U.S. patent application number 11/098512 was filed with the patent office on 2005-11-24 for welding wire for modified 9cr-1mo steel, and submerged-arc welding material.
This patent application is currently assigned to Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd.). Invention is credited to Hara, Noriyuki, Hatano, Hitoshi, Murakami, Toshio, Yamashita, Ken.
Application Number | 20050257853 11/098512 |
Document ID | / |
Family ID | 35374041 |
Filed Date | 2005-11-24 |
United States Patent
Application |
20050257853 |
Kind Code |
A1 |
Yamashita, Ken ; et
al. |
November 24, 2005 |
Welding wire for modified 9Cr-1Mo steel, and submerged-arc welding
material
Abstract
A welding wire for a modified 9Cr-1Mo steel is provided which
comprises C: 0.070 to 0.150% by mass, Si: more than 0.15% by mass,
but not more than 0.30% by mass, Mn: not less than 0.30% by mass,
but less than 0.85% by mass, Ni: 0.30 to 1.20% by mass, Cr: 8.00 to
13.00% by mass, Mo: 0.30 to 1.40% by mass, V: 0.03 to 0.40% by
mass, Nb: 0.01 to 0.15% by mass, N: 0.016 to 0.055% by mass, P: not
more than 0.010% by mass, S: not more than 0.010% by mass, Cu: less
than 0.50% by mass, Ti: not more than 0.010% by mass, Al: less than
0.10% by mass, B: less than 0.0010% by mass, W: less than 0.10% by
mass, Co: less than 1.00% by mass, and O: not more than 0.03% by
mass, wherein the total amount of Mn and Ni being not more than
1.50%. The welding wire provides good toughness without degradation
of creep rupture strength even at the PWHT temperature of
760.degree. C. or above.
Inventors: |
Yamashita, Ken;
(Fujisawa-shi, JP) ; Hara, Noriyuki;
(Fujisawa-shi, JP) ; Murakami, Toshio; (Kobe-shi,
JP) ; Hatano, Hitoshi; (Kobe-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Kabushiki Kaisha Kobe Seiko Sho
(Kobe Steel Ltd.)
Hyogo
JP
|
Family ID: |
35374041 |
Appl. No.: |
11/098512 |
Filed: |
April 5, 2005 |
Current U.S.
Class: |
148/26 ;
420/69 |
Current CPC
Class: |
B23K 2103/18 20180801;
C22C 38/04 20130101; C22C 38/48 20130101; B23K 35/0255 20130101;
B23K 2103/04 20180801; C22C 38/02 20130101; C22C 38/46 20130101;
B23K 35/3086 20130101; B23K 26/34 20130101; B23K 35/3605 20130101;
B23K 2103/05 20180801; C22C 38/44 20130101 |
Class at
Publication: |
148/026 ;
420/069 |
International
Class: |
C22C 038/48 |
Foreign Application Data
Date |
Code |
Application Number |
May 18, 2004 |
JP |
2004-148204 |
Claims
What is claimed is:
1. A welding wire consisting essentially of, by mass, C: 0.070 to
0.150%, Si: more than 0.15%, but not more than 0.30%, Mn: not less
than 0.30%, but less than 0.85%, Ni: 0.30 to 1.20%, Cr: 8.00 to
13.00%, Mo: 0.30 to 1.40%, V: 0.03 to 0.40%, Nb: 0.01 to 0.15%, N:
0.016 to 0.055%, P: not more than 0.010%, S: not more than 0.010%,
Cu: less than 0.50%, Ti: not more than 0.010%, Al: less than 0.10%,
B: less than 0.0010%, W: less than 0.10%, Co: less than 1.00%, O:
not more than 0.03%, and balance: Fe and unavoidable impurities,
the total amount of Mn and Ni being not more than 1.50%.
2. The welding wire according to claim 1, wherein the Ni content is
0.40 to 1.00% by mass.
3. The welding wire according to claim 1, wherein the Mo content is
0.80 to 1.10% by mass.
4. The welding wire according to claim 1, wherein the Cu content is
not more than 0.10% by mass.
5. The welding wire according to claim 1, wherein the Al content is
less than 0.05% by mass.
6. A submerged-arc welding material, consisting essentially of, the
welding wire according to claim 1, and a flux, said flux
comprising, by mass, CaF.sub.2: 10 to 60%, CaO: 2 to 25%, MgO: 10
to 50%, Al.sub.2O.sub.3: 2 to 30%, and Si and SiO.sub.2: 6 to 30%
in terms of SiO.sub.2.
7. The welding material according to claim 6, wherein the Ni
content of the welding wire is 0.40 to 1.00% by mass.
8. The welding material according to claim 6, wherein the Mo
content is 0.80 to 1.10% by mass.
9. The welding material according to claim 6, wherein the Cu
content is not more than 0.10% by mass.
10. The welding material according to claim 6, wherein the Al
content is less than 0.05% by mass.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to welding wires for welding
modified 9Cr-1Mo steels, which are used for various types of
heat-resistant and pressure-resistant piping, including a boiler
for power generation, a turbine, and the like. More particularly,
the invention relates to welding wires for modified 9Cr-1Mo steels,
which are used for performing a submerged arc welding (SAW) process
of the modified 9Cr-1Mo steel, and/or a tungsten inert gas (TIG)
welding process thereof, and to welding materials comprising the
combination of the welding wire and a flux.
BACKGROUND OF THE INVENTION
[0002] A modified 9Cr-1Mo steel (hereinafter referred to as
"Mod.9Cr-1Mo steel") is made of a 9Cr-1Mo steel with Nb and V added
thereto. For example, the modified 9Cr-1Mo steel is SA387Gr.91, or
SA213Gr.T91, which is specified in the American Society for Testing
and Materials (ASTM) Specification/American Society of Mechanical
Engineers (ASME) Specification, X10CrMoVNb9-1, which is specified
in the European standards (EN) Specification, or KA-STBA28,
KA-STPA28, KA-SCMV28, or KA-SFVAF28, which is specified in the
Technical Standard for Thermal Power Generating Facilities.
Hitherto, welding materials, such as welding wires, for welding
these Mod.9Cr-1Mo steels, have been developed variedly in view of
design of the components thereof for improving crack resistance,
creep rupture strength, and toughness.
[0003] For example, a welding wire has been proposed in Japanese
Patent No. 2631228 which contains 0.030 to 0.065% by mass of
carbon, which is relatively small, the atomic ratio of Nb and V to
C, namely, ((Nb+V)/C), being adjusted within a range of 0.26 to
0.35, so as to have good crack resistance, creep rupture strength,
and toughness. Further, in the welding wire material, Mn is added
to the wire for deoxidation and for maintaining strength, and Ni is
also added thereto for improvement of toughness and for decrease of
embrittlement in use under high temperature and pressure conditions
for a long time. This document discloses an example in which a post
weld heat treatment (PWHT) temperature is 740.degree. C.
[0004] JP-A No. 258894/1989 discloses a submerged arc welding
method using a flux with a Li compound added thereto so as to have
good resistance to intercrystalline crack. This welding method
comprises addition of Mn to a welding wire for deoxidation and for
maintaining strength, and addition of Ni to the wire for decrease
of embrittlement in use under high temperature and pressure
conditions for a long time. Further, this publication discloses an
example in which the PWHT temperature is 740.degree. C.
[0005] A welding wire disclosed in Japanese Patent No. 2668530 is a
welding wire for a gas-shielded arc welding process. The welding
wire contains a small content of carbon, and optimized contents of
Nb and V so as to have good crack resistance, creep rupture
strength, and toughness. Further, in the welding wire, Mn is added
to the wire for deoxidation and for maintaining strength, and Ni is
also added thereto for decrease of embrittlement in use under high
temperature and pressure conditions for a long time. This document
discloses an example in which the PWHT temperature is 740.degree.
C.
[0006] Japanese Patent No. 2529843 discloses a submerged arc
welding method which comprises restricting a Si content of a
welding wire to 0.05% by mass or less, while restricting a
SiO.sub.2 content of a flux to 5% by mass or less so as to have
good resistance to intercrystalline crack. This welding method
further comprises addition of Mn to the welding wire for
deoxidation and for maintaining strength, and addition of Ni
thereto for decrease of embrittlement in use under high temperature
and pressure conditions for a long time. Also, this document
discloses an example in which the PWHT temperature is 740.degree.
C.
[0007] In welding wires disclosed in Japanese Patent No. 2594265
and JP-B No. 36996/1994, an element W is added to the wire, and a
relationship between the W content and the Mo content is optimized,
so as to obtain good creep rupture strength. Further, Mn is added
to the welding wire for deoxidation and for maintaining strength,
and Ni is added thereto for decrease of embrittlement in use under
high temperature and pressure conditions for a long time. These
documents also disclose examples in which the PWHT temperature is
750.degree. C.
[0008] In welding materials disclosed in Japanese Patent No.
2908228 and Japanese Patent No. 2928904, Ni and Cu are combined and
added to the materials so as to obtain excellent high-temperature
strength, high-temperature corrosion resistance, and toughness.
Further, Mn is added to the material so as to fix the S content,
thereby preventing harmful effects caused by the element S,
including welding cracks, creep embrittlement, and the like, while
Ni is added thereto so as to ensure toughness by improving
toughness of a matrix, and restricting the residual
.delta.-ferrite. Further, these documents also disclose examples in
which the PWHT temperature is 740.degree. C.
[0009] A welding wire disclosed in JP-A No. 96390/1995 contains
optimized contents of Mn, Ni, and N to obtain good creep rupture
strength and toughness. The Mn is added to the wire for ensuring
the strength and for prevention of formation of bulky ferrite, and
the Ni is also added thereto for prevention of formation of the
bulky ferrite to stabilize the toughness. Further, this document
also discloses an example in which the PWHT temperature is
740.degree. C.
[0010] The above-mentioned prior art, however, has the following
problems. In some existing welding methods, approaches are taken in
terms of working conditions to improve the creep rupture strength
and toughness. More specifically, such an approach involves
increasing the PWHT temperature, which is carried out on the
overseas working conditions. In statutes pertaining to electrical
work pieces in Japan (the Technical Standard for Thermal Power
Generating Facilities), the PWHT temperature of high Cr ferrite
steels, such as the Mod.9Cr-1Mo steel, is set to 760.degree. C. or
less. For this reason, on the working conditions in Japan, the PWHT
temperature is intended to be set within a range of 740 to
750.degree. C., taking into consideration variations in the
temperature of a heat treatment furnace, resulting in the actual
temperature that does not exceed 760.degree. C. inmost cases. On
the other hand, in statutes in other countries, the PWHT
temperature is set to be raised up to an Acl transformation
temperature of a base material according to the ASME specification,
for example. Strictly speaking, there are no rules in other
countries that limit the PWHT temperature to 760.degree. C. or
less.
[0011] Thus, in some welding processes in other countries, the PWHT
temperature is intended to be set to 760.degree. C. for the purpose
of improving the creep rupture strength and toughness, and the PWHT
temperature is often increased until the actual temperature reaches
780.degree. C. In this case, a problem of the Acl transformation
temperature for a deposited metal arises. Concretely, when the PWHT
is carried out at a temperature above the Acl transformation
temperature of the deposited metal, phase transformation occurs in
the deposited metal, resulting in a danger that the creep rupture
strength may be significantly degraded. Some recent reports have
suggested that, even if the PWHT temperature does not exceed the
Acl transformation temperature of the deposited metal, the creep
rupture strength is degraded at the PWHT temperature extremely
close to the transformation temperature.
[0012] From such a background, the American Welding Society (AWS)
Specification and the EN Specification tend to restrict the total
content of Mn and Ni in the welding material to 1.5% by mass or
less for the purpose of enhancement of the Acl transformation
temperature of the deposited metal. Since there is a negative
correlation between the total content of Mn and Ni and the Acl
transformation temperature, decrease in the total content of Mn and
Ni can raise the Acl transformation temperature of the deposited
metal. Furthermore, as disclosed in the above-mentioned cited
documents, since Mn and Ni each have effects of ensuring and
improving toughness, just restriction of the total content of Mn
and Ni in the welding material under the high PWHT temperature
condition disadvantageously leads to failure in improvement of the
toughness. The above-mentioned documents do not take into
consideration the welding material whose PWHT temperature is not
less than 760.degree. C. In the welding materials disclosed in
these documents, when the PWHT temperature exceeds the Acl
transformation temperature of the deposited metal, phase
transformation might occur in the deposited metal, resulting in
significantly degraded creep rupture strength. Accordingly, a
welding wire for the Mod.9Cr-1Mo steel is required which is usable
at the PWHT temperature of 760.degree. C. or above, and has good
toughness.
SUMMARY OF THE INVENTION
[0013] The present invention has been accomplished in view of those
problems encountered with the prior art, and it is an object of the
invention to provide a welding wire for a modified 9Cr-1Mo steel
that provides good toughness without degradation of creep rupture
strength even at the PWHT temperature of 760.degree. C. or
above.
[0014] A welding wire according to one aspect of the invention
consists essentially of, by mass, C: 0.070 to 0.150%, Si: more than
0.15%, but not more than 0.30%, Mn: not less than 0.30%, but less
than 0.85%, Ni: 0.30 to 1.20%, Cr: 8.00 to 13.00%, Mo: 0.30 to
1.40%, V: 0.03 to 0.40%, Nb: 0.01 to 0.15%, N: 0.016 to 0.055%, P:
not more than 0.010%, S: not more than 0.010%, Cu: less than 0.50%,
Ti: not more than 0.010%, Al: less than 0.10%, B: less than
0.0010%, W: less than 0.10%, Co: less than 1.00%, O: not more than
0.03%, and balance: Fe and unavoidable impurities, the total amount
of Mn and Ni being not more than 1.50%.
[0015] In the present invention, the total content of Mn and Ni is
restricted to not more than 1.50% by mass, and the Co content is
also restricted to less than 1.00% by mass, so that the creep
rupture strength is not degraded even at the PWHT temperature of
760.degree. C. or above. The contents of Mn, Ni, Si, Cr, Mo, V and
Nb, each of which might affect the toughness, are optimized, while
the contents of Al, W, Ti, B, C, and O, each of which might degrade
the toughness, are restricted, resulting in the good toughness.
[0016] Preferably, in the welding wire, the Ni content may be 0.40
to 1.00% by mass, the Mo content 0.80 to 1.10% by mass, the Cu
content not more than 0.10% by mass, and the Al content less than
0.05% by mass. This improves the toughness and the creep rupture
strength.
[0017] A submerged-arc welding material according to another aspect
of the invention consists essentially of, the welding wire with the
aforesaid components, and a flux. The flux comprises, by mass,
CaF.sub.2: 10 to 60%, CaO: 2 to 25%, MgO: 10 to 50%,
Al.sub.2O.sub.3: 2 to 30%, and Si and SiO.sub.2: 6 to 30% in terms
Of SiO.sub.2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] A welding wire for a modified 9Cr-1Mo steel according to the
present invention will be hereinafter described in details. The
applicant et al have obtained the following findings from the study
of the relationship between wire components and toughness so as to
solve the aforesaid problems. That is, the applicant et al have
found that each of Mn and Ni contents should be optimized to have
good toughness, and that the best toughness is achieved by setting
the total content of Mn and Ni within a range of 0.60% to 1.50% by
mass. Further, the applicant et al have found that loadings of the
ferrite stabilizing elements should be restricted so as to prevent
the residual .delta.-ferrite, which might adversely affect the
toughness. For example, when the Mn content, and the Ni content,
and the total content of Mn and Ni are restricted, in particular,
the contents of Si, Cr, Mo, V, Nb, Al, and W among the ferrite
stabilizing elements necessarily should be restricted.
[0019] Although the element Cu has an effect of preventing the
.delta.-ferrite from remaining in a weld metal, the excessive
amount of added Cu causes embrittlement in the weld metal,
resulting in decreased toughness. Also, although the Co has a high
effect on improving the toughness by preventing the .delta.-ferrite
from remaining in the weld metal, the excessive amount of added Co
decreases an Acl transformation temperature and creep rupture
strength. The element N has effects of improving the creep rupture
strength and of preventing the .delta.-ferrite from remaining in
the weld metal. The excessive amount of N is required to exhibit an
effect of improving the toughness by addition of the N to the wire,
which might lead to blowholes. Ti and B are precipitated as fine
carbide particles and fine boride particles, respectively,
resulting in significant degradation of the toughness. Thus, the
contents of these elements need to be restricted.
[0020] Now, the reason for numeric restriction of a chemical
composition of the welding wire for the modified 9Cr--Mo steel
according to the invention will be explained below.
[0021] C: 0.070 to 0.150% by Mass
[0022] The element C has an effect of precipitating various kinds
of carbides in combination with the elements Cr, Mo, W, V, and Nb
to improve the creep rupture strength. Note that in the case of the
C content of less than 0.070% by mass, this effect is not
sufficient. In contrast, excessive addition of the element C, for
example, when the C content exceeds 0.150% by mass, leads to
degradation in crack resistance. Accordingly, the C content is
preferably 0.070 to 0.150% by mass.
[0023] Si: More than 0.15% by Mass, but not More than 0.30% by
Mass
[0024] The element Si has an effect of acting as a deoxidizing
agent to decrease the oxygen amount of a deposited metal, thereby
improving the toughness of the weld metal. Note that the welding
wire with the Si content of 0.15% by mass or less does not exhibit
the effect. In contrast, since the Si is one of the ferrite
stabilizing elements, excessive addition of the Si, for example,
when the Si content exceeds 0.30% by mass, causes the residual
.delta.-ferrite in the weld metal, thus resulting in degradation of
the toughness of the weld metal. Accordingly, the Si content is
preferably more than 0.15% by mass, but not more than 0.30% by
mass.
[0025] Mn: not Less than 0.30% by Mass, but Less than 0.85% by
Mass, Ni: 0.30 to 1.20% by Mass, and Mn+Ni: not More than 1.50% by
Mass in Total
[0026] The element Mn has an effect of acting as a deoxidizing
agent to decrease the oxygen amount of the deposited metal, thereby
improving the toughness of the weld metal. Mn and Ni are austenite
forming elements, and each of them has an effect of preventing the
degradation of the toughness due to the residual .delta.-ferrite in
the weld metal. Note that in the case of the Mn content of less
than 0.30% by mass, or in the case of the Ni content of less than
0.30% by mass, such an effect is not obtained, resulting in the
degraded toughness. In contrast, in the case of the Mn content of
at least 0.85%, or in the case of the Ni content of above 1.20% by
mass, the toughness of the weld metal is degraded. In a case where
the total content of Mn and Ni exceeds 1.50% by mass, the toughness
of the weld metal is degraded, while the Acl transformation
temperature of the deposited metal is decreased, thus resulting in
the degraded creep rupture strength. Accordingly, the Mn content is
preferably not less than 0.30% by mass, but less than 0.85% by
mass, the Ni content 0.30 to 1.20% by mass, and the total content
of Mn and Ni not more than 1.50% by mass. Note that the Ni content
is more preferably 0.40 to 1.00% by mass. This further improves the
toughness of the weld metal.
[0027] Cr: 8.00 to 13.00% by Mass
[0028] The element Cr is an important element of the Mod.9Cr-1Mo
steel, for which the welding wire of the invention is used, and
essential for ensuring the oxidation resistance and the
high-temperature strength. It should be noted that when the Cr
content is less than 8.00% by mass, the oxidation resistance and
the high-temperature strength are insufficient. In contract, since
the Cr is one of the ferrite stabilizing elements, excessive
addition of the Cr, for example, when the Cr content is greater
than 13.00% by mass, causes the residual .delta.-ferrite, thus
resulting in degradation of the toughness. Accordingly, the Cr
content is preferably 8.00 to 13.00% by mass. This provides the
excellent oxidation resistance and high-temperature strength.
[0029] Mo: 0.30 to 1.40% by Mass
[0030] The element Mo is a solid solution strengthening element,
and has an effect of improving the creep rupture strength. Note
that when the Mo content is less than 0.30% by mass, the sufficient
creep rupture strength is not obtained. In contract, since the Mo
is one of the ferrite stabilizing elements, excessive addition of
the Mo, for example, when the Mo content is greater than 1.40% by
mass, causes the residual .delta.-ferrite in the weld metal, thus
resulting in degradation of the toughness thereof. Accordingly, the
Mo content is preferably 0.30 to 1.40% by mass, and more preferably
0.80 to 1.10% by mass. This improves the creep rupture strength and
the toughness.
[0031] V: 0.03 to 0.40% by Mass
[0032] The element V is a precipitation strengthening element, and
has an effect of precipitating as carbonitride to improve the creep
rupture strength. Note that when the V content is less than 0.03%
by mass, the sufficient creep rupture strength is not obtained. In
contract, since the V is one of the ferrite stabilizing elements,
excessive addition of the V, for example, when the V content is
greater than 0.40% by mass, causes the residual .delta.-ferrite in
the weld metal, thus resulting in degradation of the toughness
thereof. Accordingly, the V content is preferably 0.03 to 0.40% by
mass.
[0033] Nb: 0.01 to 0.15% by Mass
[0034] The element Nb is an element which precipitates as a solid
solution strengthening nitride to contribute to stabilization of
the creep rupture strength. Note that when the Nb content is less
than 0.01% by mass, the sufficient creep rupture strength is not
obtained. In contract, since the Nb is one of the ferrite
stabilizing elements, excessive addition of the Nb, for example,
when the Nb content is greater than 0.15% by mass, causes the
residual .delta.-ferrite in the weld metal, thus resulting in
degradation of the toughness thereof. Accordingly, the Nb content
is preferably 0.01 to 0.15% by mass.
[0035] N: 0.016 to 0.055% by Mass
[0036] The element N is an element which precipitates as a solid
solution strengthening nitride to contribute to stabilization of
the creep rupture strength. Note that when the N content is less
than 0.016% by mass, the sufficient creep rupture strength is not
obtained. In contract, excessive addition of the N, for example,
when the N content is greater than 0.055% by mass, causes
blowholes. Accordingly, the N content is preferably 0.016 to 0.055%
by mass.
[0037] P: not More than 0.010% by Mass
[0038] The element P is an element enhancing the sensitivity to hot
cracking. When the P content exceeds 0.010% by mass, the hot
cracking occurs. Accordingly, the P content is restricted to not
more than 0.010% by mass.
[0039] S: not More than 0.010% by Mass
[0040] The element S is an element enhancing the sensitivity to hot
cracking. When the S content exceeds 0.010% by mass, the hot
cracking occur. Accordingly, the S content is restricted to not
more than 0.010% by mass.
[0041] Cu: Less than 0.50% by Mass
[0042] The element Cu is an element that degrades the toughness. In
some cases, a surface of a wire is coated with Cu plating so as to
improve energizing and feeding properties. As mentioned above,
excessive addition of the Cu, for example, when the Cu content is
not less than 0.50% by mass, causes the enbrittlement in the weld
metal, resulting in degradation of the toughness. Accordingly, the
Cu content in the whole wire including the plating is restricted to
less than 0.50% by mass. Note that the Cu content is more
preferably restricted to not more than 0.10% by mass. This improves
the toughness.
[0043] Ti: not More than 0.010% by Mass
[0044] The element Ti is precipitated as fine carbide to harden the
deposited metal, thus significantly degrading the toughness of the
weld metal. For example, when the Ti content exceeds 0.010% by
mass, the toughness is degraded. Accordingly, the Ti content is
restricted to not more than 0.010% by mass.
[0045] Al: Less than 0.10% by Mass
[0046] The element Al is one of the ferrite stabilizing elements.
Excessive addition of the Al, for example, when the Al content is
not less than 0.10% by mass, causes the residual .delta.-ferrite,
which might adversely affect the toughness of the weld metal.
Accordingly, the Al content is restricted to less than 0.10% by
mass. Note that the Al content is preferably restricted to less
than 0.05% by mass. This improves the toughness.
[0047] B: Less than 0.0010% by Mass
[0048] The element B is precipitated as carbon boride and boride to
harden the deposited metal, thus significantly degrading the
toughness of the weld metal. For example, when the B content is not
less than 0.0010% by mass, the toughness is degraded. Accordingly,
the B content is restricted to less than 0.0010% by mass.
[0049] W: Less than 0.10% by Mass
[0050] The element W is one of the ferrite stabilizing elements.
Excessive addition of the W, for example, when the W content is not
less than 0.10% by mass, causes the residual .delta.-ferrite in the
weld metal, resulting in degradation of the toughness thereof.
Accordingly, the W content is restricted to less than 0.10% by
mass.
[0051] Co: Less than 1.00% by Mass
[0052] The element Co is one of the austenite forming elements, and
has an effect of preventing the residual .delta.-ferrite in the
weld metal to improve the toughness thereof. However, excessive
addition of the Co, for example, when the Co content is not less
than 1.00% by mass, decreases the Acl transformation temperature of
the deposited metal, thus resulting in degradation of the creep
rupture strength. Accordingly, the Co content is restricted to less
than 1.00% by mass.
[0053] O: not More than 0.03% by Mass
[0054] The element O remains as the oxide in the deposited metal to
degrade the toughness of the weld metal. For example, when the O
content exceeds 0.03% by mass, the amount of residual oxide is
increased, leading to degradation of the toughness. Accordingly,
the O content is restricted to not more than 0.03% by mass.
[0055] In cases where the welding wire of the invention is used for
the welding methods, such as the submerged arc welding, current
polarity significantly affects chemical components of the deposited
metals, mechanical property, and welding workability. More
specifically, direct current electrode positive (hereinafter
referred to as DCEP) tends to increase the amount of oxygen in the
deposited metal and to degrade the toughness of the weld metal, as
compared to alternating current (AC). Further, the DCEP tends to
have magnetic blow-outs, and to cause slug winding and incomplete
fusion. In order to solve such problems, and to have good
mechanical property, the welding wire of the invention is
preferably combined in use with a flux, which comprises CaF.sub.2:
10 to 60% by mass, CaO: 2 to 25% by mass, MgO: 10 to 50% by mass,
Al.sub.2O.sub.3: 2 to 30% by mass, and Si and SiO.sub.2: 6 to 30%
in terms of SiO.sub.2 by mass in total.
[0056] Now, reasons for numeric restriction of a chemical
composition of the flux to be used in combination with the welding
wire for the modified 9Cr--Mo steel of the invention will be
explained below.
[0057] CaF.sub.2: 10 to 60% by Mass
[0058] The compound CaF.sub.2 has an effect of enhancing the
basicity of the slug to decrease the amount of oxygen in the
deposited metal, thus improving the toughness of the weld metal.
Also, the CaF.sub.2 has an effect of fixing the shape of a weld
bead, since CaF2 decreases a melting point of the slug and improves
its mobility. Note that when the CaF.sub.2 content in the flux is
less than 10% by mass, such effects are not obtained. When the
CaF.sub.2 content in the flux exceeds 60% by mass, the mobility of
the slug is excessive, thus significantly impairing the shape of
the bead. Accordingly, the CaF.sub.2 content in the flux is
preferably 10 to 60% by mass.
[0059] CaO: 2 to 25% by Mass
[0060] The compound CaO is a basic component, and has an effect of
decreasing the amount of oxygen in the deposited metal to improve
the toughness of the weld metal, in the same manner as the
above-mentioned compound CaF.sub.2. Also, the CaO has an effect of
fixing the shape of the weld bead by adjusting the viscosity of the
slug. Note that when the CaO content in the flux is less than 2% by
mass, such effects are not obtained. When the CaO content in the
flux exceeds 25% by mass, the amount of oxygen in the deposited
metal is increased, leading to degradation of the toughness of the
weld metal. Accordingly, the CaO content in the flux is preferably
2 to 25% by mass.
[0061] MgO: 10 to 50% by Mass
[0062] The compound MgO is a basic component, and has an effect of
decreasing the amount of oxygen in the deposited metal to improve
the toughness of the weld metal, in the same manner as the
above-mentioned compound CaF.sub.2. Also, the MgO has an effect of
fixing the shape of the weld bead by adjusting the viscosity of the
slug. Note that when the MgO content in the flux is less than 10%
by mass, such effects are not obtained. When the MgO content in the
flux exceeds 50% by mass, the amount of oxygen in the deposited
metal is increased, leading to degradation of the toughness of the
weld metal. Accordingly, the MgO content in the flux is preferably
10 to 50% by mass.
[0063] Al.sub.2O.sub.3: 2 to 30% by Mass
[0064] The compound Al.sub.2O.sub.3 has an effect of enhancing a
melting point of the slug to adjust its mobility, thereby fixing
the shape of the weld bead. Note that when the Al.sub.2O.sub.3
content in the flux is less than 2% by mass, this effect is not
obtained. When the Al.sub.2O.sub.3 content in the flux exceeds 30%
by mass, slug seizing occurs, and impairs the external appearance
of the bead. Accordingly, the Al.sub.2O.sub.3 content in the flux
is preferably 2 to 30% by mass.
[0065] Si and SiO.sub.2: 6 to 30% by Mass in Total
[0066] The compound SiO.sub.2 has an effect of enhancing the
viscosity of the slug to fix the shape of the weld bead. Note that
when the SiO.sub.2 content in the flux is less than 6% by mass,
this effect is not obtained. Since the SiO.sub.2 is reduced in an
arc to be included in the deposited metal, excessive addition of
the SiO.sub.2 increases the amount of reduced Si, which leads to
degradation of the toughness due to the residual .delta.-ferrite in
the deposited metal. The same goes for the element Si, which is
arbitrarily added as a deoxidizing agent into the flux. For this
reason, the total amount of Si and SiO.sub.2 in the flux needs to
be restricted, including SiO.sub.2 in a soluble glass which is used
as a binder when granulating the flux. Accordingly, the total
content of Si and SiO.sub.2 in the flux is preferably 6 to 30% by
mass in terms of SiO.sub.2.
[0067] Such essential components can be added in the form of a
single material, a compound including these elements themselves, an
ore, a fused flux, or the like. For example, a fluorite may be
added as the CaF.sub.2; calcis and a melting flux as the CaO; a
magnesia clinker and a melting flux as the MgO; alumina and a
melting flux as Al.sub.2O.sub.3; and potassium feldspar, albite, a
melting flux, and the like as the SiO.sub.2. In addition to the
above-mentioned essential components, alloy powders, oxides, and/or
fluorides may be arbitrarily added to the flux so as to adjust the
alloy components and the welding workability. Note that unavoidable
impurities in the welding wire of the invention include Sn, As, Sb,
Ca, Mg, and the like.
EXAMPLE
[0068] Now, effects of the examples according to the invention will
be explained by comparing with comparative examples, which depart
from the scope of the invention. First, the welding wires with
compositions shown in the following Tables 1 and 2 were used as
first examples of the invention. A sample steel plate with a
composition shown in Table 3, and having a thickness of 20 mm, a
groove angle of 45 degrees, and a root gap of 13 mm, was welded
using each of the above-mentioned welding wires in the submerged
arc welding process under a condition shown in the following Table
4. The toughness and creep rupture strength of each of the
thus-obtained weld metals were evaluated. The following Table 5
shows a composition of a combination flux. The combination flux was
obtained by granulating flux raw materials and a water glass as a
binder, sintering them at 500 to 550.degree. C. for one hour, so
that the content of 10.times.48 mesh grains in the whole flux was
70% by mass or more. Note that the balance shown in the Tables 1
and 2 are Fe and unavoidable impurities.
[0069] Table 1
[0070] Table 2
[0071] Table 3
[0072] Table 4
[0073] Table 5
[0074] Now, evaluation methods of respective items will be
described hereinafter. First, for classification, radiographic
testing (JIS specification Z3104) was performed on the samples
after welding. Results corresponding to JIS Class 1 were judged as
good, and then the samples with these results were subjected to the
PWHT at 760.degree. C. for two hours. Thereafter, creep rupture and
Charpy impact tests were performed on these samples. The creep test
used a specimen with a diameter of 6.0 mm as specified in JIS
specification Z2273. And test conditions were as follows:
650.degree. C., and 86 MPa. The Charpy impact test used a specimen
as specified in JIS specification Z3114, and a test temperature was
set to 20.degree. C. The respective specimens for the creep rupture
and impact tests were extracted from a center part of the weld
metal located in the through-thickness center region of the
obtained plate. Criterions for evaluation of those tests were as
follows. In the radiographic testing, the results corresponding to
JIS Class 1 were judged good (.largecircle.), and the results other
than the JIS Class 1 judged bad (x). In the creep rupture test,
results with a rupture time of not less than 1000 hours were judged
as good (.largecircle.), and results with a rupture time of less
than 1000 hours judged bad (x). In the Charpy impact test, results
with vE20.degree. C. average of not less than 40 J were judged good
(.largecircle.), and results with vE20.degree. C. average of less
than 40 J judged bad (x). Those results are shown in the following
Tables 7 and 9. The following Tables 6 and 8 show the chemical
components of the deposited metals.
[0075] Table 6
[0076] Table 7
[0077] Table 8
[0078] Table 9
[0079] Now, in second examples of the invention, the welding wires
of the examples No. W43 to W48 and No. W55 to W60 shown in the
above Table 2 were subjected to wire drawing treatments until a
diameter of each wire reached 1.6 mm. A sample steel plate with a
composition shown in the above Table 3, and having a thickness of
12 mm, a groove angle of 45 degrees, and a root gap of 6 mm, was
welded using each of the above-mentioned welding wires in the TIG
welding process under a condition shown in the following Table 10.
The toughness and creep rupture strength of each of the
thus-obtained weld metals were evaluated in the same way and
condition as those of the aforesaid first example. Results are
shown in the following Table 11.
[0080] Table 10
[0081] Table 11
[0082] As shown in the above Tables 6 and 7, in the wire of the
comparative example No. W1, the C content was less than that
covered by the scope of the invention. Thus, the strength of the
wire was insufficient, and the creep rupture time did not satisfy a
predetermined requirement of performance. In the wire of the
comparative example No. W2, the C content exceeded that covered by
the scope of the invention, thus leading to occurrence of hot
cracking in the radiographic testing. In the wire of the
comparative example No. W3, since the Si content was less than that
covered by the scope of the invention, the deposited metal lacked
deoxidation, and the toughness of the weld metal did not satisfy
the predetermined requirement of performance. In the wire of the
comparative example No. W4, since the Si content exceeded that
covered by the scope of the invention, the .delta.-ferrite remained
in the weld metal, and the toughness did not satisfy the
predetermined requirement of performance. In the wire of the
comparative example No. W5, since the Mn content was less than that
covered by the scope of the invention, the deposited metal lacked
deoxidation, and the .delta.-ferrite remained in the weld metal. As
a result, the toughness did not satisfy the predetermined
requirement of performance. In the wire of the comparative example
No. W6, the Mn content and the total content of Mn and Ni exceeded
those covered by the scope of the invention, resulting in the
decreased Acl transformation temperature of the deposited metal,
and hence the creep rupture time did not satisfy the predetermined
requirement of performance. Also, the toughness did not meet the
predetermined requirement of performance.
[0083] In the wire of the comparative example No. W7, the P content
exceeded that covered by the scope of the invention, thus leading
to occurrence of hot cracking in the radiographic testing. Also, in
the wire of the comparative example No. W8, the S content exceeded
that covered by the scope of the invention, thus leading to
occurrence of hot cracking in the radiographic testing. In the wire
of the comparative example No. W9, since the Cu content exceeded
that covered by the scope of the invention, the toughness did not
meet the predetermined requirement of performance. In the wire of
the comparative example No. W10, since the Ni content was less than
that covered by the scope of the invention, the .delta.-ferrite
remained in the weld metal, and the toughness did not satisfy the
predetermined requirement of performance. In the wire of the
comparative example No. W11, the Ni content and the total content
of Mn and Ni exceeded those covered by the scope of the invention,
resulting in the decreased Acl transformation temperature of the
deposited metal, and hence the creep rupture time did not satisfy
the predetermined requirement of performance. Also, the toughness
did not meet the predetermined requirement of performance. In the
wire of the comparative example No. W12, the Co content exceeded
that covered by the scope of the invention, resulting in the
decreased Acl transformation temperature of the deposited metal,
and hence the creep rupture time did not satisfy the predetermined
requirement of performance.
[0084] In the wire of the comparative example No. W13, since the Cr
content was less than that covered by the scope of the invention,
the strength of the wire was insufficient, and the creep rupture
time did not satisfy the predetermined requirement of performance.
In the wire of the comparative example No. W14, since the Cr
content exceeded that covered by the scope of the invention, the
.delta.-ferrite remained in the weld metal, and the toughness
thereof did not satisfy the predetermined requirement of
performance. In the wire of the comparative example No. W15, since
the Mo content was less than that covered by the scope of the
invention, the strength of the wire was insufficient, and the creep
rupture time did not satisfy the predetermined requirement of
performance. In the wire of the comparative example No. W16, since
the Mo content exceeded that covered by the scope of the invention,
the .delta.-ferrite remained in the weld metal, and the toughness
did not satisfy the predetermined requirement of performance.
Likewise, in the wire of the comparative example No. W17, since the
Al content exceeded that covered by the scope of the invention, the
.delta.-ferrite remained in the weld metal, and the toughness did
not satisfy the predetermined requirement of performance. In the
wire of the comparative example No. W18, the Ti content exceeded
that covered by the scope of the invention, resulting in
significantly enhancing the strength of the weld metal, and hence
the toughness did not meet the predetermined requirement of
performance. In the wire of the comparative example No. W19, the Nb
content was less than that covered by the scope of the invention,
leading to insufficient strength of the wire, resulting in the fact
that the creep rupture time did not satisfy the predetermined
requirement of performance. In the wire of the comparative example
No. W20, since the Nb content exceeded that covered by the scope of
the invention, the .delta.-ferrite remained in the weld metal, and
the toughness did not satisfy the predetermined requirement of
performance.
[0085] In the wire of the comparative example No. W21, the V
content was less than that covered by the scope of the invention,
leading to insufficient strength of the wire, and hence the creep
rupture time did not satisfy the predetermined requirement of
performance. In the wire of the comparative example No. W22, since
the V content exceeded that covered by the scope of the invention,
the .delta.-ferrite remained in the weld metal, and the toughness
thereof did not satisfy the predetermined requirement of
performance. In the wire of the comparative example No. W23, since
the W content exceeded that covered by the scope of the invention,
the .delta.-ferrite remained in the weld metal, and the toughness
thereof did not satisfy the predetermined requirement of
performance. Likewise, in the wire of the comparative example No.
W24, the B content exceeded that covered by the scope of the
invention, resulting in the residual .delta.-ferrite in the weld
metal, and hence the toughness did not meet the predetermined
requirement of performance. In the wire of the comparative example
No. W25, the N content was less than that covered by the scope of
the invention, leading to insufficient strength. Thus, the creep
rupture time failed to satisfy the predetermined requirement of
performance. In the wire of the comparative example No. W26, the N
content exceeded that covered by the scope of the invention,
leading to occurrence of blowholes in the radiographic testing.
[0086] In the wire of the comparative example No. W27, the O
content exceeded that covered by the scope of the invention,
resulting in an increased oxygen amount in the deposited metal, and
thus the toughness did not meet the predetermined requirement of
performance. In the wire of the comparative example No. W28, the
total content of Mn and Ni exceeded those covered by the scope of
the invention, resulting in decreased Acl crystal temperature of
the deposited metal, and thus the creep rupture time did not
satisfy the predetermined requirement of performance. Also, the
toughness did not meet the predetermined requirement of
performance. In the wire of the comparative example No. W29, since
the Cu content exceeded that covered by the scope of the invention,
the toughness did not satisfy the predetermined requirement of
performance. Further, since the Nb content was less than that
covered by the scope of the invention, the strength was
insufficient, and hence the creep rupture time did not meet the
predetermined requirement of performance. In the wire of the
comparative example No. W30, the Ni content and the total content
of Mn and Ni exceeded those covered by the scope of the invention,
resulting in the fact that the toughness did not satisfy the
predetermined requirement of performance. This decreased the Acl
transformation temperature of the deposited metal. Even addition of
the Nb in an amount more than that covered by the scope of the
invention did not allow the creep rupture time to meet the
predetermined requirement of performance.
[0087] In contrast, as shown in the above Tables 8 and 9, in the
wires of the examples No. W31 to W60, since the component
compositions were within the scope of the invention, even when
performing the PWHT at 760.degree. C. for two hours, the toughness
and creep rupture time satisfied the predetermined requirements of
performance. Especially, in the wires No. W49 to W60, the Cu, Ni,
Mo, and Al contents each were adjusted within a preferable range,
thereby achieving excellent toughness and creep rupture strength.
As shown in the above Table 11, the wires No. W43 to W48, and wires
No. W55 to W60 satisfied the predetermined requirement of
performance even in the TIG welding process. In particular, the
wires No. W55 to W60, in which the Cu, Ni, Mo, and Al contents each
were within the preferable range, had significantly excellent
toughness and creep rupture strength.
1 TABLE 1 Wire composition (% by mass) No. C Si Mn P S Cu Ni Co Cr
Mo Al Comparative W1 0.067 0.16 0.65 0.006 0.005 Less than 0.02
0.67 Less than 0.02 8.70 0.95 0.005 examples W2 0.158 0.23 0.55
0.006 0.007 0.03 0.89 Less than 0.02 8.89 0.99 0.010 W3 0.115 0.13
0.80 0.005 0.002 0.05 0.30 Less than 0.02 9.65 1.05 0.010 W4 0.121
0.33 0.73 0.005 0.003 0.10 0.45 Less than 0.02 8.23 1.00 0.017 W5
0.126 0.27 0.24 0.004 0.004 0.03 0.55 0.83 11.50 0.45 0.008 W6
0.137 0.26 0.86 0.006 0.007 Less than 0.02 1.00 0.54 12.70 0.40
0.009 W7 0.110 0.18 0.74 0.14 0.008 Less than 0.02 0.60 Less than
0.02 9.50 0.89 Less than 0.002 W8 0.080 0.16 0.79 0.005 0.014 Less
than 0.02 0.65 Less than 0.02 8.70 0.75 0.004 W9 0.075 0.17 0.83
0.007 0.005 0.54 0.54 Less than 0.02 8.72 1.04 0.004 W10 0.074 0.20
0.78 0.005 0.004 Less than 0.02 0.23 0.78 11.50 0.53 0.019 W11
0.120 0.24 0.33 0.004 0.005 0.05 1.24 Less than 0.02 8.54 0.67
0.030 W12 0.125 0.25 0.43 0.008 0.005 0.20 0.52 1.03 8.45 0.91 Less
than 0.002 W13 0.114 0.26 0.42 0.005 0.006 0.30 0.38 Less than 0.02
7.93 0.84 0.050 W14 0.108 0.19 0.55 0.003 0.007 0.04 0.42 Less than
0.02 13.11 0.53 0.004 W15 0.120 0.23 0.62 0.005 0.008 0.25 0.55
Less than 0.02 8.49 0.21 0.004 W16 0.080 0.25 0.25 0.008 0.005 0.28
0.56 Less than 0.02 9.56 1.44 0.010 W17 0.089 0.24 0.38 0.009 0.007
0.40 0.67 Less than 0.02 8.95 0.89 0.110 W18 0.093 0.26 0.79 0.008
0.004 Less than 0.02 0.32 Less than 0.02 8.56 0.94 0.004 W19 0.099
0.16 0.84 0.007 0.003 Less than 0.02 0.45 0.89 12.83 0.43 0.005 W20
0.078 0.17 0.70 0.006 0.003 0.02 0.52 0.34 9.85 0.85 0.005 W21
0.073 0.19 0.83 0.006 0.003 0.03 0.35 0.05 8.65 0.86 0.005 W22
0.085 0.16 0.84 0.004 0.005 0.08 0.23 Less than 0.02 8.89 0.93
0.070 W23 0.120 0.16 0.75 0.007 0.005 Less than 0.02 0.50 0.30 8.83
0.92 0.075 W24 0.095 0.23 0.62 0.005 0.005 Less than 0.02 0.45 Less
than 0.02 8.85 0.99 0.003 W25 0.134 0.17 0.84 0.008 0.008 0.04 0.42
0.91 10.54 0.37 0.003 W26 0.098 0.16 0.57 0.007 0.007 0.02 0.55
Less than 0.02 9.05 0.89 0.003 W27 0.110 0.21 0.65 0.001 0.001 0.05
0.47 Less than 0.02 8.93 0.79 0.007 W28 0.095 0.25 0.84 0.007 0.007
Less than 0.02 0.69 Less than 0.02 8.99 0.95 0.005 W29 0.120 0.24
0.10 0.004 0.004 0.52 0.55 Less than 0.02 9.65 1.05 0.010 W30 0.108
0.19 0.55 0.002 0.002 0.08 1.46 Less than 0.02 8.89 0.99 0.010 Wire
composition (% by mass) No. Ti Nb V W B N O Mn + Ni Comparative W1
0.002 0.065 0.280 Less than 0.02 0.0002 0.040 0.013 1.32 examples
W2 0.002 0.047 0.380 Less than 0.02 0.0003 0.038 0.009 1.44 W3 Less
than 0.002 0.052 0.040 0.09 0.0007 0.050 0.015 1.10 W4 0.005 0.055
0.240 Less than 0.02 0.0003 0.028 0.005 1.18 W5 0.007 0.030 0.230
0.03 0.0003 0.020 0.014 0.79 W6 0.005 0.059 0.350 Less than 0.02
0.0003 0.036 0.005 1.86 W7 Less than 0.002 0.130 0.034 0.05 0.0003
0.038 0.006 1.34 W8 0.003 0.050 0.190 Less than 0.02 Less than
0.0002 0.045 0.008 1.44 W9 0.003 0.048 0.050 Less than 0.02 Less
than 0.0002 0.051 0.009 1.37 W10 0.004 0.056 0.078 Less than 0.02
Less than 0.0002 0.039 0.007 1.01 W11 0.003 0.075 0.190 Less than
0.02 0.0002 0.033 0.006 1.57 W12 0.005 0.054 0.150 Less than 0.02
0.0002 0.029 0.006 0.95 W13 0.007 0.045 0.250 Less than 0.02 0.0003
0.035 0.007 0.80 W14 Less than 0.002 0.039 0.240 0.07 0.0003 0.038
0.011 0.97 W15 Less than 0.002 0.083 0.240 Less than 0.02 0.0003
0.037 0.010 1.17 W16 0.005 0.058 0.190 Less than 0.02 0.0003 0.019
0.008 0.81 W17 0.005 0.059 0.170 Less than 0.02 Less than 0.0002
0.026 0.007 1.05 W18 0.012 0.055 0.150 Less than 0.02 0.0004 0.032
0.008 1.11 W19 0.004 0.004 0.380 0.03 0.0005 0.035 0.012 1.29 W20
0.004 0.158 0.037 Less than 0.02 0.0003 0.045 0.011 1.22 W21 0.005
0.048 0.022 0.05 0.0003 0.035 0.014 1.18 W22 0.004 0.056 0.460 Less
than 0.02 0.0003 0.038 0.013 1.07 W23 0.003 0.085 0.200 0.12 0.0003
0.038 0.011 1.25 W24 0.005 0.062 0.290 Less than 0.02 0.0013 0.045
0.010 1.07 W25 0.007 0.092 0.050 Less than 0.02 0.0003 0.013 0.010
1.26 W26 0.004 0.049 0.190 Less than 0.02 0.0003 0.059 0.012 1.12
W27 Less than 0.002 0.048 0.180 Less than 0.02 0.0003 0.036 0.034
1.12 W28 Less than 0.002 0.058 0.220 Less than 0.02 Less than
0.0002 0.039 0.009 1.53 W29 Less than 0.002 Less than 0.002 0.150
Less than 0.02 0.0005 0.032 0.008 0.65 W30 0.002 0.163 0.190 Less
than 0.02 0.0003 0.033 .0006 2.01
[0088]
2 TABLE 2 Wire composition (% by mass) No. C Si Mn P S Cu Ni Co Cr
Mo Al Examples W31 0.085 0.22 0.60 0.002 0.009 0.13 0.35 0.02 11.95
0.71 0.051 W32 0.133 0.16 0.46 0.005 0.004 0.32 0.35 0.31 12.71
1.12 0.060 W33 0.078 0.20 0.74 0.004 0.009 0.35 0.30 0.51 12.29
1.17 0.080 W34 0.100 0.20 0.63 0.007 0.003 0.38 0.39 0.58 11.26
1.27 0.072 W35 0.134 0.21 0.64 0.002 0.002 0.42 0.34 0.36 8.12 1.19
0.098 W36 0.104 0.19 0.48 0.006 0.008 0.42 0.34 0.04 10.75 1.13
0.098 W37 0.137 0.20 0.37 0.010 0.003 0.42 0.39 0.04 11.53 1.17
0.062 W38 0.108 0.16 0.40 0.008 0.002 0.46 1.04 0.61 9.04 1.26
0.054 W39 0.091 0.18 0.37 0.002 0.009 0.30 0.36 0.05 10.21 1.15
0.062 W40 0.108 0.21 0.33 0.007 0.004 0.32 1.03 0.82 11.33 0.48
0.087 W41 0.094 0.22 0.40 0.002 0.002 0.36 0.38 0.85 10.77 1.13
0.053 W42 0.071 0.19 0.32 0.009 0.008 0.39 0.98 0.48 12.39 1.38
0.093 W43 0.079 0.20 0.73 0.002 0.002 0.41 0.35 0.43 11.12 0.52
0.074 W44 0.139 0.18 0.77 0.006 0.002 0.44 0.33 0.62 10.79 0.74
0.084 W45 0.105 0.18 0.84 0.008 0.002 0.47 0.35 Less than 0.02
12.30 0.62 0.052 W46 0.150 0.20 0.76 0.009 0.003 0.49 0.38 0.23
9.02 0.78 0.069 W47 0.077 0.21 0.32 0.002 0.003 0.15 1.14 0.72
10.07 0.71 0.078 W48 0.094 0.20 0.75 0.003 0.004 0.26 0.67 Less
than 0.02 8.55 0.93 0.002 W49 0.128 0.23 0.35 0.010 0.010 Less than
0.02 1.00 0.44 8.94 0.98 0.031 W50 0.141 0.22 0.75 0.002 0.007 0.07
0.64 0.74 10.39 0.80 Less than 0.002 W51 0.105 0.17 0.44 0.005
0.007 0.09 0.84 0.44 11.38 0.85 0.002 W52 0.132 0.21 0.36 0.004
0.010 0.03 0.74 0.20 9.09 0.80 Less than 0.002 W53 0.118 0.18 0.36
0.002 0.006 0.06 0.94 0.60 8.18 1.09 0.002 W54 0.133 0.24 0.54
0.004 0.002 0.03 0.80 0.78 11.18 0.80 0.007 W55 0.121 0.24 0.31
0.002 0.002 0.03 0.99 0.82 9.14 0.93 0.005 W56 0.092 0.27 0.32
0.009 0.002 0.07 0.77 0.94 8.37 1.01 Less than 0.002 W57 0.115 0.23
0.47 0.002 0.008 0.09 0.73 0.39 9.17 0.93 0.005 W58 0.079 0.22 0.37
0.004 0.005 0.06 0.92 0.24 11.04 1.07 Less than 0.002 W59 0.126
0.16 0.60 0.004 0.006 0.02 0.79 0.54 10.95 0.69 0.004 W60 0.094
0.30 0.50 0.005 0.004 0.04 0.87 0.28 12.90 1.10 0.006 Wire
composition (% by mass) No. Ti Nb V W B N O Mn + Ni Examples W31
0.003 0.063 0.303 0.02 Less than 0.0002 0.018 0.025 0.95 W32 0.004
0.047 0.227 0.05 0.0003 0.030 0.026 0.81 W33 0.007 0.116 0.379 0.09
0.0003 0.037 0.009 1.04 W34 Less than 0.002 0.091 0.286 Less than
0.02 0.0003 0.035 0.005 1.02 W35 0.006 0.036 0.099 0.06 0.0004
0.038 0.022 0.98 W36 0.007 0.074 0.397 Less than 0.02 0.0003 0.036
0.029 0.82 W37 0.007 0.119 0.242 0.08 0.0003 0.016 0.021 0.76 W38
Less than 0.002 0.074 0.209 0.09 0.0002 0.051 0.020 1.44 W39 0.009
0.140 0.148 0.03 0.0003 0.023 0.010 0.73 W40 0.009 0.038 0.297 0.09
0.0003 0.055 0.009 1.36 W41 0.009 0.046 0.057 0.07 Less than 0.0002
0.031 0.023 0.78 W42 0.002 0.084 0.287 Less than 0.02 0.0003 0.049
0.027 1.30 W43 0.006 0.043 0.265 0.09 0.0003 0.033 0.017 1.08 W44
0.009 0.037 0.125 0.02 0.0003 0.033 0.015 1.10 W45 0.005 0.067
0.080 0.08 0.0007 0.054 0.011 1.19 W46 0.004 0.096 0.235 0.09
0.0005 0.052 0.023 1.14 W47 Less than 0.002 0.072 0.080 0.08 0.0003
0.032 0.008 1.46 W48 0.002 0.056 0.220 Less than 0.02 0.0009 0.033
0.025 1.42 W49 Less than 0.002 0.094 0.052 0.09 0.0003 0.029 0.017
1.35 W50 0.008 0.130 0.182 0.07 0.0003 0.033 0.012 1.39 W51 0.002
0.084 0.125 0.02 0.0003 0.053 0.013 1.28 W52 Less than 0.002 0.127
0.089 0.04 0.0003 0.028 0.017 1.10 W53 0.002 0.104 0.107 0.08
0.0003 0.021 0.012 1.30 W54 0.007 0.028 0.299 0.04 0.0003 0.031
0.009 1.34 W55 0.005 0.101 0.138 0.03 0.0003 0.054 0.015 1.30 W56
Less than 0.002 0.12 0.358 0.06 0.0003 0.017 0.004 1.09 W57 0.005
0.084 0.371 0.05 0.0003 0.043 0.020 1.19 W58 Less than 0.002 0.107
0.365 0.06 0.0003 0.025 0.027 1.29 W59 0.004 0.077 0.081 0.04
0.0003 0.034 0.022 1.39 W60 0.006 0.144 0.323 0.04 0.0003 0.047
0.006 1.37
[0089]
3TABLE 3 Type Composition (% by mass) of steel C Si Mn P S Cu Ni Co
Cr Mo Al Ti Nb V W B N Mod.9Cr--1Mo 0.09 0.32 0.41 0.008 0.007 0.05
0.03 Less 8.95 1.02 Less Less 0.08 0.2 Less Less 0.042 Steel than
than than than than 0.01 0.002 0.002 0.02 0.005
[0090]
4TABLE 4 Welding Power supply Welding Welding Welding Preheating
and Other method Wire diameter polarity current voltage Welding
speed attitude interpass temperatures condition SAW 2.4 mm DCEP 400
A 29.about.30 V 30 cm/min Flat 200.about.250.degree. C. Single
electrode
[0091]
5 TABLE 5 Components Content (% by mass) CaF.sub.2 27 CaO 7 MgO 30
Al.sub.2O.sub.3 9 Total SiO.sub.2 14 ZrO.sub.2 3 NaF 2
Fe.sub.2O.sub.3 1 Mn 0.7 Si 0.5 REM 0.2 Ca 0.2 B.sub.2O.sub.3 0.1
Balance Unavoidable impurities
[0092]
6 TABLE 6 Deposited metal composition (% by mass) No. C Si Mn P S
Cu Ni Co Cr Mo Al Ti Comparative W1 0.052 0.19 0.72 0.008 0.007
Less than 0.02 0.66 Less than 0.02 8.32 0.94 0.008 0.003 examples
W2 0.156 0.29 0.66 0.008 0.009 0.03 0.90 Less than 0.02 8.45 0.98
0.013 0.003 W3 0.087 0.12 0.82 0.008 0.004 0.05 0.31 Less than 0.02
8.86 1.02 0.013 Less than 0.002 W4 0.117 0.48 0.77 0.008 0.005 0.09
0.45 Less than 0.02 8.02 0.97 0.020 0.007 W5 0.093 0.43 0.23 0.007
0.006 0.03 0.55 0.82 10.34 0.44 0.011 0.009 W6 0.126 0.33 1.28
0.008 0.009 Less than 0.02 0.10 0.55 11.17 0.39 0.011 0.007 W7
0.095 0.22 0.78 0.015 0.010 Less than 0.02 0.58 Less than 0.02 8.73
0.86 0.003 0.002 W8 0.046 0.16 0.81 0.008 0.018 Less than 0.02 0.65
Less than 0.02 8.09 0.73 0.007 0.005 W9 0.007 0.16 0.84 0.008 0.007
0.52 0.54 Less than 0.02 8.11 1.03 0.007 0.005 W10 0.055 0.30 0.81
0.008 0.006 Less than 0.02 0.04 0.78 10.34 0.51 0.022 0.006 W11
0.113 0.36 0.36 0.007 0.007 0.04 1.33 Less than 0.02 8.13 0.66
0.033 0.005 W12 0.093 0.30 0.58 0.008 0.007 0.21 0.52 1.00 8.05
0.89 0.004 0.007 W13 0.090 0.39 0.57 0.008 0.008 0.28 0.38 Less
than 0.02 7.49 0.82 0.053 0.009 W14 0.086 0.23 0.66 0.005 0.009
0.02 0.42 Less than 0.02 11.64 0.52 0.007 0.002 W15 0.120 0.26 0.70
0.008 0.009 0.23 0.55 Less than 0.02 8.12 0.22 0.007 0.002 W16
0.064 0.31 0.46 0.008 0.007 0.27 0.56 Less than 0.02 8.87 1.41
0.013 0.007 W17 0.056 0.31 0.55 0.011 0.009 0.39 0.70 Less than
0.02 8.31 0.87 0.113 0.007 W18 0.057 0.36 0.81 0.008 0.006 Less
than 0.02 0.32 Less than 0.02 8.00 0.91 0.007 0.014 W19 0.083 0.20
0.88 0.008 0.005 Less than 0.02 0.45 0.88 11.31 0.40 0.008 0.006
W20 0.079 0.16 0.60 0.007 0.005 Less than 0.02 0.51 0.30 9.01 0.83
0.008 0.006 W21 0.066 0.16 0.95 0.006 0.005 0.02 0.35 0.03 8.07
0.85 0.008 0.007 W22 0.059 0.16 1.10 0.007 0.007 0.07 0.25 Less
than 0.02 8.55 0.91 0.073 0.006 W23 0.093 0.21 0.79 0.008 0.007
Less than 0.02 0.49 0.30 8.20 0.91 0.078 0.005 W24 0.078 0.32 0.70
0.007 0.007 Less than 0.02 0.44 Less than 0.02 8.23 0.89 0.011
0.007 W25 0.105 0.27 0.85 0.009 0.007 0.03 0.42 0.90 9.57 0.35
0.007 0.009 W26 0.099 0.24 0.67 0.008 0.009 Less than 0.02 0.55
Less than 0.02 8.36 0.87 0.006 0.006 W27 0.076 0.33 0.72 0.004
0.008 0.04 0.49 Less than 0.02 8.26 0.76 0.009 Less than 0.002 W28
0.064 0.41 0.94 0.008 0.008 Less than 0.02 0.60 Less than 0.02 8.33
0.93 0.008 0.002 W29 0.112 0.37 0.36 0.007 0.007 0.51 0.55 Less
than 0.02 8.84 1.03 0.013 0.002 W30 0.078 0.23 0.66 0.005 0.009
0.07 1.48 Less than 0.02 8.26 0.96 0.014 0.004 Deposited metal
composition (% by mass) No. Nb V W B N O Mn + Ni Comparative W1
0.042 0.270 Less than 0.02 0.0004 0.035 0.033 1.38 examples W2
0.030 0.358 Less than 0.02 0.0005 0.034 0.030 1.56 W3 0.032 0.030
0.04 0.0009 0.041 0.055 1.13 W4 0.034 0.239 Less than 0.02 0.0005
0.027 0.026 1.22 W5 0.019 0.220 0.02 0.0005 0.021 0.052 0.78 W6
0.036 0.340 Less than 0.02 0.0005 0.033 0.027 1.38 W7 0.093 0.024
0.03 0.0005 0.035 0.026 1.36 W8 0.031 0.180 Less than 0.02 0.0005
0.038 0.028 1.46 W9 0.029 0.040 Less than 0.02 0.0003 0.041 0.031
1.38 W10 0.035 0.068 Lese than 0.02 0.0004 0.036 0.027 0.85 W11
0.049 0.170 Less than 0.02 0.0004 0.032 0.026 1.69 W12 0.034 0.130
Less than 0.02 0.0004 0.029 0.026 1.10 W13 0.028 0.240 Less than
0.02 0.0005 0.034 0.027 0.95 W14 0.024 0.230 0.03 0.0005 0.035
0.031 1.08 W15 0.054 0.230 Less than 0.02 0.0005 0.034 0.030 1.25
W16 0.036 0.170 Less than 0.02 0.0005 0.020 0.028 1.02 W17 0.037
0.160 Less than 0.02 0.0004 0.027 0.027 1.25 W18 0.034 0.140 Less
than 0.02 0.0006 0.031 0.028 1.13 W19 0.005 0.360 0.02 0.0007 0.033
0.032 1.33 W20 0.120 0.027 Less than 0.02 0.0005 0.040 0.031 1.10
W21 0.030 0.012 0.03 0.0005 0.033 0.034 1.30 W22 0.035 0.450 Less
than 0.02 0.0005 0.036 0.033 1.35 W23 0.056 0.190 0.06 0.0005 0.035
0.031 1.29 W24 0.034 0.270 Less than 0.02 0.0015 0.044 0.032 1.14
W25 0.060 0.040 Less than 0.02 0.0005 0.014 0.030 1.27 W26 0.032
0.170 Less than 0.02 0.0005 0.048 0.032 1.22 W27 0.030 0.165 Less
than 0.02 0.0005 0.034 0.064 1.21 W28 0.038 0.216 Less than 0.02
Less than 0.0002 0.036 0.029 1.54 W29 Less than 0.002 0.140 Less
than 0.02 0.0005 0.031 0.028 0.91 W30 0.126 0.180 Less than 0.02
0.0003 0.032 0.026 2.14
[0093]
7 TABLE 7 Radiographic test Creep rupture test Charpy impact test
No. Wire No. Results Evaluation Rupture time (Time) Evaluation
vE20.degree. C. average(J) Evaluation Comparative 1 W1 JIS Class 1
.largecircle. 437 X 45 .largecircle. examples 2 W2 Other than JIS
Class 1 X -- -- -- -- (Hot crack) 3 W3 JIS Class 1 .largecircle.
1238 .largecircle. 15 X 4 W4 JIS Class 1 .largecircle. 1150
.largecircle. 19 X 5 W5 JIS Class 1 .largecircle. 1250
.largecircle. 13 X 6 W6 JIS Class 1 .largecircle. 535 X 15 X 7 W7
Other than JIS Class 1 X -- -- -- -- (Hot crack) 8 W8 Other than
JIS Class 1 X -- -- -- -- (Hot crack) 9 W9 JIS Class 1
.largecircle. 1350 .largecircle. 25 X 10 W10 JIS Class 1
.largecircle. 1480 .largecircle. 11 X 11 W11 JIS Class 1
.largecircle. 180 X 19 X 12 W12 JIS Class 1 .largecircle. 459 X 48
.largecircle. 13 W13 JIS Class 1 .largecircle. 445 X 54
.largecircle. 14 W14 JIS Class 1 .largecircle. 1530 .largecircle. 6
X 15 W15 JIS Class 1 .largecircle. 182 X 45 .largecircle. 16 W16
JIS Class 1 .largecircle. 1450 .largecircle. 6 X 17 W17 JIS Class 1
.largecircle. 1350 .largecircle. 22 X 18 W18 JIS Class 1
.largecircle. 1670 .largecircle. 6 X 19 W19 JIS Class 1
.largecircle. 453 X 75 .largecircle. 20 W20 JIS Class 1
.largecircle. 1947 .largecircle. 18 X 21 W21 JIS Class 1
.largecircle. 352 X 36 X 22 W22 JIS Class 1 .largecircle. 1380
.largecircle. 26 X 23 W23 JIS Class 1 .largecircle. 1250
.largecircle. 15 X 24 W24 JIS Class 1 .largecircle. 1870
.largecircle. 12 X 25 W25 JIS Class 1 .largecircle. 759 X 49
.largecircle. 26 W26 Other than JIS Class 1 X -- -- -- --
(Blowhole) 27 W27 JIS Class 1 .largecircle. 1140 .largecircle. 5 X
28 W28 JIS Class 1 .largecircle. 253 X 11 X 29 W29 JIS Class 1
.largecircle. 132 X 20 X 30 W30 JIS Class 1 .largecircle. 760 X 5
X
[0094]
8 TABLE 8 Deposited metal Composition (% by mass) No. C Si Mn P S
Cu Ni Co Cr Mo Examples W31 0.067 0.21 0.90 0.006 0.011 0.12 0.34
0.02 10.68 0.69 W32 0.118 0.12 0.45 0.007 0.006 0.31 0.23 0.31
11.26 1.10 W33 0.059 0.18 0.78 0.007 0.011 0.34 0.29 0.51 10.93
1.15 W34 0.083 0.18 0.71 0.008 0.005 0.36 0.38 0.58 10.15 1.25 W35
0.118 0.19 0.93 0.006 0.004 0.40 0.33 0.37 7.73 1.16 W36 0.087 0.17
0.60 0.008 0.010 0.41 0.35 0.04 9.75 1.11 W37 0.122 0.18 0.47 0.009
0.005 0.41 0.37 0.05 10.35 1.15 W38 0.091 0.14 0.55 0.009 0.004
0.45 0.95 0.61 8.44 1.24 W39 0.074 0.15 0.53 0.006 0.011 0.30 0.27
0.05 9.34 1.13 W40 0.092 0.19 0.46 0.008 0.006 0.29 0.95 0.82 10.20
0.46 W41 0.076 0.21 0.55 0.006 0.004 0.35 0.14 0.85 9.77 1.11 W42
0.052 0.17 0.49 0.009 0.010 0.37 0.97 0.49 11.01 1.36 W43 0.060
0.18 0.99 0.006 0.004 0.39 0.25 0.44 10.03 0.50 W44 0.124 0.14 1.02
0.008 0.004 0.43 0.29 0.63 9.78 0.72 W45 0.088 0.14 1.17 0.009
0.005 0.46 0.11 Less than 0.02 10.94 0.60 W46 0.136 0.18 1.01 0.009
0.005 0.49 0.34 0.23 8.42 0.76 W47 0.058 0.19 0.35 0.006 0.006 0.14
1.12 0.73 9.23 0.70 W48 0.076 0.18 0.55 0.005 0.005 0.25 0.31 Less
than 0.02 8.21 0.92 W49 0.113 0.22 0.44 0.010 0.010 Less than 0.02
0.98 0.44 9.36 0.96 W50 0.126 0.31 0.79 0.006 0.006 0.06 0.65 0.74
9.48 0.78 W51 0.088 0.25 0.58 0.007 0.007 0.08 0.84 0.44 10.23 0.83
W52 0.117 0.30 0.52 0.007 0.007 0.03 0.74 0.20 8.47 0.78 W53 0.101
0.25 0.52 0.006 0.006 0.05 0.94 0.61 7.78 1.07 W54 0.117 0.33 0.65
0.007 0.007 0.03 0.81 0.79 10.08 0.78 W55 0.104 0.33 0.49 0.006
0.006 0.03 1.00 0.82 8.51 0.91 W56 0.074 0.37 0.48 0.009 0.009 0.06
0.77 0.96 7.93 0.98 W57 0.099 0.22 0.60 0.006 0.006 0.08 0.73 0.39
8.54 0.91 W58 0.060 0.31 0.53 0.007 0.007 0.06 0.92 0.24 9.97 1.05
W59 0.110 0.23 0.69 0.007 0.007 0.02 0.79 0.55 9.90 0.67 W60 0.076
0.41 0.62 0.007 0.007 0.023 0.88 0.28 11.40 1.08 Deposited metal
Composition (% by mass) No. Al Ti Nb V W B N O Mn + Ni Examples W31
0.016 0.004 0.034 0.290 Less than 0.02 0.0002 0.021 0.038 1.24 W32
0.019 0.005 0.024 0.215 0.02 0.0005 0.029 0.037 0.68 W33 0.027
0.008 0.070 0.366 0.04 0.0004 0.034 0.030 1.07 W34 0.023 0.002
0.053 0.274 Less than 0.02 0.0004 0.032 0.026 1.09 W35 0.033 0.008
0.016 0.088 0.03 0.0006 0.034 0.039 1.26 W36 0.031 0.009 0.042
0.383 Less than 0.02 0.0005 0.033 0.035 0.95 W37 0.021 0.009 0.072
0.230 0.04 0.0005 0.019 0.039 0.84 W38 0.018 Less than 0.002 0.042
0.197 0.04 0.0004 0.044 0.038 1.50 W39 0.020 0.011 0.087 0.137 Less
than 0.02 0.0005 0.024 0.030 0.80 W40 0.029 0.011 0.017 0.284 0.04
0.0005 0.046 0.029 1.41 W41 0.017 0.011 0.023 0.046 0.04 0.0002
0.029 0.039 0.69 W42 0.031 0.004 0.048 0.274 Less than 0.02 0.0005
0.042 0.037 1.46 W43 0.025 0.008 0.021 0.253 0.04 0.0005 0.031
0.036 1.24 W44 0.027 0.011 0.017 0.114 Less than 0.02 0.0005 0.031
0.034 1.31 W45 0.017 0.007 0.037 0.070 0.04 0.0009 0.046 0.031 1.28
W46 0.023 0.006 0.057 0.224 0.04 0.0006 0.044 0.039 1.35 W47 0.024
Less than 0.002 0.040 0.069 0.04 0.0005 0.030 0.028 1.47 W48 0.003
0.003 0.038 0.200 Less than 0.02 0.0010 0.031 0.038 0.86 W49 0.010
Less than 0.002 0.055 0.042 0.05 0.0004 0.028 0.036 1.42 W50 0.002
0.010 0.080 0.171 0.05 0.0004 0.031 0.032 1.44 W51 0.007 0.004
0.048 0.114 Less than 0.02 0.0004 0.045 0.033 1.42 W52 0.016 Less
than 0.002 0.078 0.078 0.02 0.0004 0.027 0.036 1.26 W53 0.015 0.004
0.062 0.096 0.04 0.0004 0.022 0.032 1.46 W54 0.012 0.009 0.010
0.287 0.02 0.0004 0.030 0.029 1.45 W55 0.016 0.007 0.060 0.127 0.02
0.0005 0.046 0.034 1.48 W56 0.012 Less then0.002 0.074 0.345 0.03
0.0004 0.019 0.025 1.25 W57 0.002 0.007 0.049 0.358 0.02 0.0004
0.038 0.038 1.33 W58 0.006 Less than 0.002 0.064 0.352 0.03 0.0004
0.025 0.037 1.45 W59 0.003 0.006 0.044 0.070 0.02 0.0005 0.031
0.038 1.48 W60 0.007 0.008 0.089 0.311 0.02 0.0004 0.041 0.027
1.49
[0095]
9 TABLE 9 Radiographic test Creep rupture test Charpy impact test
No. Wire No. Results Evaluation Rupture time (Time) Evaluation
vE20.degree. C. average(J) Evaluation Examples 31 W31 JIS Class 1
.largecircle. 1370 .largecircle. 68 .largecircle. 32 W32 JIS Class
1 .largecircle. 1154 .largecircle. 75 .largecircle. 33 W33 JIS
Class 1 .largecircle. 1668 .largecircle. 71 .largecircle. 34 W34
JIS Class 1 .largecircle. 1902 .largecircle. 78 .largecircle. 35
W35 JIS Class 1 .largecircle. 1987 .largecircle. 86 .largecircle.
36 W36 JIS Class 1 .largecircle. 1144 .largecircle. 76
.largecircle. 37 W37 JIS Class 1 .largecircle. 1144 .largecircle.
75 .largecircle. 38 W38 JIS Class 1 .largecircle. 1896
.largecircle. 95 .largecircle. 39 W39 JIS Class 1 .largecircle.
1730 .largecircle. 76 .largecircle. 40 W40 JIS Class 1
.largecircle. 1954 .largecircle. 47 .largecircle. 41 W41 JIS Class
1 .largecircle. 1885 .largecircle. 79 .largecircle. 42 W42 JIS
Class 1 .largecircle. 1930 .largecircle. 85 .largecircle. 43 W43
JIS Class 1 .largecircle. 1750 .largecircle. 57 .largecircle. 44
W44 JIS Class 1 .largecircle. 1902 .largecircle. 66 .largecircle.
45 W45 JIS Class 1 .largecircle. 1911 .largecircle. 65
.largecircle. 46 W46 JIS Class 1 .largecircle. 1839 .largecircle.
78 .largecircle. 47 W47 JIS Class 1 .largecircle. 1955
.largecircle. 60 .largecircle. 48 W48 JIS Class 1 .largecircle.
1402 .largecircle. 88 .largecircle. 49 W49 JIS Class 1
.largecircle. 3450 .circleincircle. 123 .circleincircle. 50 W50 JIS
Class 1 .largecircle. 2579 .circleincircle. 118 .circleincircle. 51
W51 JIS Class 1 .largecircle. 2702 .circleincircle. 116
.circleincircle. 52 W52 JIS Class 1 .largecircle. 2319
.circleincircle. 110 .circleincircle. 53 W53 JIS Class 1
.largecircle. 3692 .circleincircle. 124 .circleincircle. 54 W54 JIS
Class 1 .largecircle. 2191 .circleincircle. 107 .circleincircle. 55
W55 JIS Class 1 .largecircle. 2591 .circleincircle. 117
.circleincircle. 56 W56 JIS Class 1 .largecircle. 2598
.circleincircle. 114 .circleincircle. 57 W57 JIS Class 1
.largecircle. 2679 .circleincircle. 128 .circleincircle. 58 W58 JIS
Class 1 .largecircle. 2338 .circleincircle. 126 .circleincircle. 59
W59 JIS Class 1 .largecircle. 3152 .circleincircle. 118
.circleincircle. 60 W60 JIS Class 1 .largecircle. 2023
.circleincircle. 115 .circleincircle.
[0096]
10TABLE 10 Preheating and Welding Power supply Welding Welding
Welding interpass method Wire diameter polarity current voltage
Welding speed attitude temperatures Shielding gas TIG 1.6 mm DCEP
240 A 10.about.13 V 10 cm/min Flat 200.about.250.degree. C.
Composition: 100% Ar Flow rate Inside 25 L/min Outside 25 L/min
[0097]
11 TABLE 11 Radiographic test Creep rupture test Charpy impact test
No. Wire No. Results Evaluation Rupture time (Time) Evaluation
vE20.degree. C. average(J) Evaluation Examples 61 W43 JIS Class 1
.largecircle. 1545 .largecircle. 91 .largecircle. 62 W44 JIS Class
1 .largecircle. 1779 .largecircle. 109 .largecircle. 63 W45 JIS
Class 1 .largecircle. 1460 .largecircle. 126 .largecircle. 64 W46
JIS Class 1 .largecircle. 1391 .largecircle. 110 .largecircle. 65
W47 JIS Class 1 .largecircle. 1769 .largecircle. 125 .largecircle.
66 W48 JIS Class 1 .largecircle. 1283 .largecircle. 111
.largecircle. 67 W55 JIS Class 1 .largecircle. 3502
.circleincircle. 148 .circleincircle. 68 W56 JIS Class 1
.largecircle. 3871 .circleincircle. 149 .circleincircle. 69 W57 JIS
Class 1 .largecircle. 3550 .circleincircle. 176 .circleincircle. 70
W58 JIS Class 1 .largecircle. 3354 .circleincircle. 168
.circleincircle. 71 W59 JIS Class 1 .largecircle. 4109
.circleincircle. 164 .circleincircle. 72 W60 JIS Class 1
.largecircle. 2163 .circleincircle. 155 .circleincircle.
* * * * *