U.S. patent application number 15/540816 was filed with the patent office on 2017-12-28 for corrosion resistant cemented carbide for fluid handling.
The applicant listed for this patent is SANDVIK INTELLECTUAL PROPERTY AB. Invention is credited to Selassie DORVLO, Milena MECH, Henrik NORDENSTROM.
Application Number | 20170369973 15/540816 |
Document ID | / |
Family ID | 55085635 |
Filed Date | 2017-12-28 |
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United States Patent
Application |
20170369973 |
Kind Code |
A1 |
DORVLO; Selassie ; et
al. |
December 28, 2017 |
CORROSION RESISTANT CEMENTED CARBIDE FOR FLUID HANDLING
Abstract
A cemented carbide for fluid handling components or a seal ring
has a composition in wt %; about 7-11 Ni; about 0.5-2.5
Cr.sub.3C.sub.2; and about 0.5-1 Mo; and a balance of WC, with an
average WC grain size greater than or equal to 4 .mu.m.
Inventors: |
DORVLO; Selassie; (Solihull,
GB) ; MECH; Milena; (Royal Leamington Spa, GB)
; NORDENSTROM; Henrik; (Vendelso, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SANDVIK INTELLECTUAL PROPERTY AB |
Sandviken |
|
SE |
|
|
Family ID: |
55085635 |
Appl. No.: |
15/540816 |
Filed: |
December 28, 2015 |
PCT Filed: |
December 28, 2015 |
PCT NO: |
PCT/EP2015/081283 |
371 Date: |
June 29, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62098211 |
Dec 30, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 29/08 20130101;
C22C 29/067 20130101 |
International
Class: |
C22C 29/08 20060101
C22C029/08; C22C 29/06 20060101 C22C029/06 |
Claims
1. A cemented carbide for a fluid handling component or seal ring,
the cemented carbide having a composition comprising in wt %
(weight %): a balance of WC; about 7-11 Ni; about 0.5-2.5
Cr.sub.3C.sub.2; and about 0.5-2.5 Mo, wherein the composition has
an average WC grain size greater than or equal to 4 .mu.m.
2. The cemented carbide of claim 1, wherein the composition further
comprises of from about 0.3 to about 1.5 wt % Nb.
3. The cemented carbide according to claim 1, wherein the
composition comprises from about 8.0 to about 10.1wt % Ni.
4. The cemented carbide according to claim 3, wherein the
composition comprises of from about 8.0 to about 9.0 wt % Ni.
5. The cemented carbide according to claim 3, wherein the
composition comprises of from about 9.1 to about 10.1 wt % Ni.
6. The cemented carbide according to claim 1, wherein the
composition comprises from about 0.7 to about 1.0wt %
Cr.sub.3C.sub.2.
7. The cemented carbide according to claim 6, wherein the
composition comprises from about 0.7 to about 0.9 wt %
Cr.sub.3C.sub.2.
8. The cemented carbide according to claim 6, wherein the
composition comprises from about 0.8 to about 1.0 wt %
Cr.sub.3C.sub.2.
9. The cemented carbide according to claim 1, wherein the
composition comprises from about 0.7 to about 1.0wt % Mo.
10. The cemented carbide according to claim 9, wherein the
composition comprises from about 0.7 to about 0.9 wt % Mo.
11. The cemented carbide according to claim 9, wherein the
composition comprises from about 0.8 to about 1.0 wt % Mo.
12. The cemented carbide according to claim 1, wherein the
composition comprises of from about 87.9 to about 90.6 wt % WC.
13. The cemented carbide of claim 12, wherein the composition
comprises of from about 87.9 to about 89.1 wt % WC
14. The cemented carbide of claim 12, wherein the composition
comprises of from about 89.4 to about 90.6 wt % WC
15. The cemented carbide according to claim 1, wherein the
composition has a density of about 14.3 to about 14.7
g/cm.sup.3.
16. The cemented carbide according to claim 1, wherein the
composition has an average grain size of greater than or equal to
about 4 to about 10 .mu.m.
Description
TECHNICAL FIELD/INDUSTRIAL APPLICABILITY
[0001] The present disclosure relates to cemented carbides for flow
components, and more particularly to fluid handling components such
as seal rings having improved service life.
BACKGROUND
[0002] Seal rings are the key critical component in mechanical
shaft seals for pumps where corrosion resistance is an issue.
Cemented carbides show a good mechanical performance in this kind
of application.
[0003] Similarly, cemented carbide flow components, the primary
function of which is to control the pressure and flow of well
products, are used in, for example, the oil and gas industry where
components are subjected to high pressures of multi-media fluid
where there is a corrosive environment. A cemented carbide grade
with Ni--Cr--Mo binder having improved corrosion resistance for use
in choke valves is disclosed in WO2012/045815, also assigned to the
assignee of the present disclosure
[0004] One of the most important properties for seal rings is
thermal conductivity. This is crucial for seal rings because during
the operation of a pump the friction between the seal rings
generates heat. This heat needs to be conducted away; otherwise the
heat will lead to a temperature increase in the sealing gap, which
again can lead to evaporation of the lubricating film and dry
running. Point temperatures of over 300.degree. C. can be reached
during seal ring dry running. Thus, the thermal conductivity of the
seal ring material is vitally important in dissipating the
temperature generated. Materials with low thermal conductivities
tend to fail prematurely in service due to thermal cracking.
Therefore, there is still a need for a type or grade of cemented
carbide having high thermal conductivity and high corrosion
resistance.
SUMMARY
[0005] It is an aspect of the present disclosure to provide a
cemented carbide for fluid handling components and for a seal ring,
all of which having improved corrosion resistance.
[0006] The present disclosure therefore provides a cemented carbide
composition for fluid handling components and/or seal rings
comprises in wt % about balance WC; about 7-11 Ni; about 0.5 to 2.5
Cr.sub.3C.sub.2; and about 0.5 to about 2.5 Mo.
[0007] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter further comprises of from 0.3 to
1.5 wt % Nb.
[0008] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 8.0 to about 10.1 wt % Ni.
[0009] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 8.0 to about 9.0 wt % Ni, such as 8.49 wt %
[0010] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 9.1 to about 10.1 wt % Ni, such as 9.6 wt %
[0011] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 0.7 to about 1.0wt % Cr.sub.3C.sub.2.
[0012] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 0.7 to about 0.9 wt % Cr.sub.3C.sub.2, such as 0.8 wt
%
[0013] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 0.8 to about 1.0 wt % Cr.sub.3C.sub.2, such as 0.9 wt
%.
[0014] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 0.7 to about 1.0wt % Mo.
[0015] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 0.7 to about 0.9 wt % Mo, such as 0.8 wt %.
[0016] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 0.8 to about 1.0 wt % Mo, such as 0.9 wt %.
[0017] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 88.0 to about 90.6 wt % WC.
[0018] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 87.9 to about 89.1 wt % WC, such as 88.6 wt %.
[0019] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition comprising
from about 89.4 to about 90.5 wt % WC, such as 89.91 wt %
[0020] In an embodiment, the composition as defined hereinabove or
hereinafter has an average grain size of from about 4 .mu.m to
about 10 .mu.m, such as 8 .mu.m.
[0021] In an embodiment, a cemented carbide for a fluid handling
component or seal ring as defined hereinabove or hereinafter, has a
composition comprising in wt %: of 89.91% WC; of 8.49 Ni; of 0.8
Cr.sub.3C.sub.2; and of 0.8 Mo, wherein the composition has an
average grain size equal to or greater than 4 .mu.m.
[0022] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a composition has a density
of about 14.3 to about 14.7 g/cm.sup.3, such as about 14.4 to about
14.6 g/cm.sup.3.
[0023] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a density of from 14.4 to
14.6 g/cm3.
[0024] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a hardness of from 1000 to
1100 HV30.
[0025] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a toughness of from 10 to 13
MPa m.
[0026] In an embodiment, a cemented carbide for a fluid handling
component or seal ring as defined hereinabove or hereinafter, the
cemented carbide having a composition comprising in wt % of 88.6%
WC; of 9.6 Ni; of 0.9 Cr.sub.3C.sub.2; and of 0.9 Mo, wherein the
composition has an average WC grain size greater than 4 .mu.m.
[0027] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has an average WC grain size of
8 .mu.m.
[0028] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a hardness of about 990
HV30.
[0029] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a toughness of about 12.2
MPa m.
[0030] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a density of 14.4
g/cm.sup.3.
[0031] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has an average WC grain size of
4 .mu.m.
[0032] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a hardness of 1290 HV30.
[0033] In an embodiment, the cemented carbide composition as
defined hereinabove or hereinafter has a toughness of about 11.6
MPa m.
[0034] The foregoing summary, as well as the following detailed
description of the embodiments, will be better understood when read
in conjunction with the appended drawings. It should be understood
that the embodiments depicted are not limited to the precise
arrangements and instrumentalities shown.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is an SEM image of an embodiment of cemented carbide
for a flow component or seal ring.
[0036] FIG. 2 is an SEM image of another embodiment of cemented
carbide for a flow component or a seal ring.
[0037] FIG. 3 is an SEM image of another embodiment of cemented
carbide for a flow component or a seal ring.
[0038] FIG. 4 is an SEM image of another embodiment of cemented
carbide for a flow component or a seal ring.
DETAILED DESCRIPTION
[0039] As used herein, the term "about" means plus or minus 10% of
the numerical value of the number with which it is being used.
Therefore, about 50% means in the range of 45%-55%.
[0040] As will be described fully herein, embodiments of the
present disclosure relate to cemented carbides for flow components
(herein, the term "component" means parts or pieces), particularly
for seal rings used in the oil and gas industry, where the
components are subjected to high pressures of multi-media fluid and
where there is a corrosive environment. Under severe conditions of
multi flow media; these components may suffer from extreme mass
loss by exposure to solid particle erosion, acidic corrosion
erosion-corrosion synergy and cavitation mechanisms even when
fitted with cemented carbide trims.
[0041] Seal rings are the key critical component in mechanical
shaft seals for pumps. The seal rings act as barriers in pumps
(i.e., to separate liquids and confine pressure) by preventing
leakage and excluding contamination. Cemented carbide shows a good
mechanical performance in this kind of application.
[0042] The cemented carbide seal rings of the present disclosure
have improved application relevant properties, such as improved
corrosion resistance. The carbon content within the sintered
cemented carbide should be kept within a narrow range in order to
retain a high resistance to corrosion and wear, as well as have a
high toughness. The carbon level of the sintered structure is held
in the lower portion of the range between free carbon in the
microstructure (top limit) and eta-phase initiation (bottom
limit).
[0043] Conventional powder metallurgical methods, such as (but not
limited to) milling, drying, pressing, shaping, sintering and
sinter hipping, which are used for manufacture of conventional
cemented carbides are used to manufacture embodiments of the
present disclosure.
[0044] A cemented carbide for seal rings (CR) according to an
embodiment the present disclosure has a composition in weight
percent % of about balance WC; 7-11 Ni; 0.5-2.5 Cr.sub.3C.sub.2;
and Mo of about 0.5 to about 2.5.
[0045] It should be appreciated that the following examples are
illustrative, non-limiting examples. The compositions and results
of the embodiments are shown in Tables 1 and 2 below.
EXAMPLES
TABLE-US-00001 [0046] TABLE 1 Ref A B C Sample CR seal ring CR seal
ring CR seal ring WC 88.6 88.6 89.91 WC grain size (.mu.m) 4 8 8
TiC (wt %) 0 0 0 Co (wt %) 0 0 0 Ni (wt %) 9.6 9.6 8.49 Mo (wt %)
0.9 0.9 0.8 Cr.sub.3C.sub.2 (wt %) 0.9 0.9 0.8
TABLE-US-00002 TABLE 2 Ref A B C Sample CR seal CR seal ring CR
seal ring ring Density (gm/cm.sup.3) 14.4 14.4 14.4-14.6 Hardness
(Hv30) 1290 990 1000-1100 Toughness (K1c) 11.6 12.2 10.0-13.0
In the examples below the powders were sourced from the following
suppliers: (W,Ti)C from Zhuzhou or HC Starck, Co from Umicore or
Freeport, Ni from Inco, Mo from HC Starck and Cr.sub.3C.sub.2 from
Zhuzhou or HC Starck
Example 1
[0047] A cemented carbide grade with the composition in wt-% of
about 88.6 WC; about 0.9 Cr.sub.3C.sub.2; about 0.9 Mo; and about
9.6 Ni was producing using WC powder with an average FSSS (Fisher
Sub Sieve Sizer) particle size (d50) of greater than about 0.5
.mu.m, for example, about 4 to about 8. The cemented carbide
samples were prepared from powders forming the hard constituents
and powders forming the binder. The powders were wet milled
together with lubricant and anti-flocculating agent until a
homogeneous mixture was obtained and granulated by drying. The
dried powder was pressed on the Tox press to bodies and `green
machined` before sintering. Sintering was performed at
1360-1410.degree. C. for about 1 hour in vacuum, followed by
applying a high pressure, 50 bar Argon, at sintering temperature
for about 30 minutes to obtain a dense structure before cooling.
The sintered structure is shown in FIG. 1 with a grain size of 0.8
.mu.m.
[0048] Referring to Table 2, with WC grain size of about 4 .mu.m
has a hardness HV30 of about 1290 and a toughness of K1C 11.6 MPa
m. With WC grain size of about 8 .mu.m the harness HV30 is about
990 and the toughness K1C IS 12.2 MPa m. It can be observed that
when the coarser raw material is used (4 or 8 .mu.m) the hardness
is reduced and the toughness increased. FIG. 2 is an SEM image of
the sintered structure with a grain size of 4 .mu.m. FIG. 3 is an
SEM image of the sintered structure with a grain size of 8
.mu.m.
Example 2
[0049] A cemented carbide grade with the compositions in wt-% of
about 89.91 WC; about 0.8 Cr.sub.3C.sub.2; about 0.8 Mo; and about
8.49 Ni and was produced using WC powder with an average FSSS
particle size (d.sub.50) of greater than about about 4 .mu.m and/or
about 8 .mu.m. The cemented carbide samples were prepared from
powders forming the hard constituents and powders forming the
binder. The powders were wet milled together with lubricant and
anti-flocculating agent until a homogeneous mixture was obtained
and granulated by drying. The dried powder was pressed on the Tox
press to bodies and `green machined` before sintering. Sintering
was performed at 1360-1410.degree. C. for about 1 hour in vacuum,
followed by applying a high pressure, 50 bar Argon, at sintering
temperature for about 30 minutes to obtain a dense structure before
cooling. The sintered structure with a grain size of 8 .mu.m is
shown in FIG. 4.
[0050] The composition mentioned has the following properties:
density: 14.4-14.6 g/cm3; hardness HV30: 1000-1100 and toughness
K1C: 10-13 MPa m. The grades disclosed herein demonstrate improved
corrosion resistance in comparison to a standard seal ring grade.
Corrosion resistance was determined using a modified test to ASTM
G61. ASTM G61 covers a procedure for conducting potential dynamic
polarization measurements. The modification of this standard has
been in the media used. Instead of using 3.5% NaCl solution in the
tests, artificial seawater according to ASTM D1141 was used as the
media. Furthermore, the flushed port cell used in ASTM G61 was
replaced by sealing the specimen with epoxy to avoid crevice
corrosion on the edge of the sample. The pitting potential was used
as a measure for comparison. The higher the value, the better is
the corrosion resistance of the material. The value measured for a
standard seal ring grade was Epit=263 mV SCE. However, for the
above CR grade the Epit=443 mV SCE showing improved corrosion
resistance.
[0051] As discussed supra, one of the key properties for seal rings
is thermal conductivity. One way to increase thermal conductivity
is to increase the average WC grain size. Thermal conductivity was
measured between a cemented carbide grade of 88.6% WC, 9.6%
Nicke1,0.9% Cr.sub.3C.sub.2 and 0.9% Mo having an average WC grain
size of 0.8 .mu.m. As shown in Table 3 below, the higher the grain
size the higher the thermal conductivity.
TABLE-US-00003 TABLE 3 Thermal conductivity (W/(mK)) Temperature
(.degree. C.) Choke valve grade A Room temperature 46 85 200 53 80
401 53 72 1000 55 62
Itemized List of Embodiments
[0052] 1. A cemented carbide for a fluid handling component or seal
ring, the cemented carbide having a composition comprising in wt %:
[0053] a balance of WC; [0054] of 7-11 Ni; [0055] of 0.5-2.5
Cr.sub.3C.sub.2; and [0056] of 0.5-2.5 Mo, [0057] wherein the
composition has an average WC grain size greater than 4 .mu.m.
[0058] 2. The cemented carbide of item 1, wherein the composition
further comprises of from 0.3 to 1.5 wt % Nb.
[0059] 3. The cemented carbide of items 1 or 2, wherein the
composition has an average grain size of 8 .mu.m.
[0060] 4. A cemented carbide for a fluid handling component or seal
ring, the cemented carbide having a composition comprising in wt %:
[0061] of 89.91% WC; [0062] of 8.49 Ni; [0063] of 0.8
Cr.sub.3C.sub.2; and [0064] of 0.8 Mo, [0065] wherein the
composition has an average grain size greater than 4 .mu.m.
[0066] 5. The cemented carbide of item 4, wherein the composition
has an average grain size of 8 .mu.m.
[0067] 6. The cemented carbide of item 4 or 5, wherein the
composition has a density of from 14.4 to 14.6 g/cm.sup.3.
[0068] 7. The cemented carbide of any of items 4-6, wherein the
composition has a hardness of from 1000 to 1100 HV30.
[0069] 8. The cemented carbide of any of items 4-7, wherein the
composition has a toughness of from 10 to 13 MPa m.
[0070] 9. A cemented carbide for a fluid handling component or seal
ring, the cemented carbide having a composition comprising in wt %:
[0071] of 88.6% WC; [0072] of 9.6 Ni; [0073] of 0.9
Cr.sub.3C.sub.2; and [0074] of 0.9 Mo, [0075] wherein the
composition has an average WC grain size greater than 4 .mu.m.
[0076] 10. The cemented carbide of item 9, wherein the composition
has an average WC grain size of 8 .mu.m.
[0077] 11. The cemented carbide of items 9 or 10, wherein the
composition has a hardness of from 990 HV30.
[0078] 12. The cemented carbide of any of items 9-11, wherein the
composition has a toughness of from 12.2 MPa m.
[0079] 13. The cemented carbide of any of items 9-12, wherein the
composition has a density of from 14.4 g/cm.sup.3.
[0080] 14. The cemented carbide of item 9, wherein the composition
has an average WC grain size of 4 .mu.m.
[0081] 15. The cemented carbide of item 9 or 14, wherein the
composition has a hardness of from 1290 HV30.
[0082] 16. The cemented carbide of any of items 9, 14 or 15,
wherein the composition has a toughness of about 11.6 MPa m.
Although the present embodiments have been described in relation to
particular aspects thereof, many other variations and modifications
and other uses will become apparent to those skilled in the art. It
is preferred therefore, that the present embodiment(s) be limited
not by the specific disclosure herein, but only by the appended
claims.
* * * * *