U.S. patent application number 10/805276 was filed with the patent office on 2004-09-09 for use of zinc alloys.
This patent application is currently assigned to Grillo-Werke AG. Invention is credited to Jahny, Andrea, Knepper, Michael, Spriestersbach, Jochen, Wisniewski, Jurgen.
Application Number | 20040173294 10/805276 |
Document ID | / |
Family ID | 32928934 |
Filed Date | 2004-09-09 |
United States Patent
Application |
20040173294 |
Kind Code |
A1 |
Knepper, Michael ; et
al. |
September 9, 2004 |
Use of zinc alloys
Abstract
Zinc alloys containing from 5 to 35% by weight of aluminum and
optionally further alloy components are used as constructional zinc
for strips and plates.
Inventors: |
Knepper, Michael; (Mulheim
a. d. Ruhr, DE) ; Spriestersbach, Jochen; (Marl,
DE) ; Jahny, Andrea; (Duisburg, DE) ;
Wisniewski, Jurgen; (Wesel, DE) |
Correspondence
Address: |
JACOBSON HOLMAN PLLC
400 SEVENTH STREET N.W.
SUITE 600
WASHINGTON
DC
20004
US
|
Assignee: |
Grillo-Werke AG
|
Family ID: |
32928934 |
Appl. No.: |
10/805276 |
Filed: |
March 22, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10805276 |
Mar 22, 2004 |
|
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09831377 |
Aug 22, 2001 |
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09831377 |
Aug 22, 2001 |
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PCT/EP99/08664 |
Nov 11, 1999 |
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Current U.S.
Class: |
148/557 |
Current CPC
Class: |
E04C 2/08 20130101; E04F
13/12 20130101 |
Class at
Publication: |
148/557 |
International
Class: |
C22F 001/16 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 17, 1998 |
DE |
198 52 987.2 |
Claims
1. Use of zinc alloys containing from 5 to 35% by weight of
aluminum and optionally further alloy components as constructional
zinc for strips and plates.
2. The use according to claim 1, characterized by an aluminum
content of from 5 to 20%, preferably from 8 to 15% by weight.
3. The use according to claim 1 or 2, characterized by: from 0.002
to 0.04% by weight of indium; and/or from 0.002 to 0.04% by weight
of calcium; and/or from 0.002 to 0.4% by weight of titanium; and/or
from 0.05 to 0.8% by weight of manganese; as said further alloy
components.
4. The use according to any of claims 1 to 3, characterized by from
3 to 100 ppm of boron, from 3 to 100 ppm of carbon, from 3 to 50
ppm of magnesium, from 2 to 500 ppm of vanadium, from 2 to 500 ppm
of silicon and/or from 2 to 500 ppm of nickel as said further alloy
components.
Description
[0001] The present invention relates to the use of zinc alloys as
constructional zinc for strips and plates.
[0002] To date, strips and plates of alloyed zinc for building
purposes have contained, in addition to zinc with a content of
99.99%, from 0.005 to 0.05% by weight of aluminum as well as
additions of from 0.05 to 0.2% by weight of titanium and copper.
This alloy is described, for example, in DE 17 58 498 and meets the
standard DIN 17 770, part 1.
[0003] The preparation of this material is generally performed
using the casting-and-rolling process in which strips are prepared
in a predetermined thickness by a continuous procedure
(melting-casting-rollin- g-winding), which strips are subsequently
cut into narrow strips or plates on shear lines.
[0004] This material is highly stable in the atmosphere. Its
surface first reacts with atmospheric oxygen to form zinc oxide.
Then, by the action of water, zinc hydroxide is formed which is
converted to a dense, firmly adhering and water-insoluble coat
layer of basic zinc carbonate by reaction with atmospheric carbon
dioxide. This protective layer is also responsible for the high
corrosion resistance of such strips and plates.
[0005] In contrast to the behavior of the surface of zinc facing
the free atmosphere, other conditions prevail on the lower side of
the zinc strips and plates, i.e., on the side facing away from
weathering influences. If the lower side of the zinc strips and
plates is additionally exposed to moisture or condensed water for
an extended period of time due to poor aeration and deaeration,
enhanced corrosion must be expected due to such mistakes of
building physics and laying technology. Such water inclusions,
water irruptions and condensation water eventually lead to punctual
deep corrosion (pinholing) which can spread two-dimensionally.
[0006] To avoid these consequences, care has to be taken that
sufficient aeration and deaeration of the base construction of zinc
strip or plate coatings is provided by observing the prescriptions
and regulations of the VOB and DIN standards as well as technical
rules of the art and decrees of the building authorities.
[0007] Due to increased ecological demands on the resistance of
these materials, it has been desired to develop materials having
comparable mechanical properties, but with clearly more beneficial
corrosion properties. The strips and plates previously used as
constructional zinc lose 4 to 5 .mu.m per year.
[0008] Such an improved material has been described in DE-A-195 45
487 and is characterized by a copper content of from 0.02 to 0.075%
by weight and manganese content of from 0.075 to 0.75% by weight.
However, tests made on this material have shown that the demands
made on such a material in practice are still far from being met,
despite the considerable improvements.
[0009] From DD-4822, the use of zinc-aluminum alloys is known which
contain from 1 to 63% of aluminum and from 99 to 37% of zinc and
which are rendered suitable for objects having a high
deformability, i.e., so-called superplastic behavior, by a special
heat treatment. This is important to the drawing of wires and to
the rolling, extruding, forging, deep-drawing of sheets, and to
bending. There are no indications to the corrosion behavior of
these alloys and thus their usability as constructional zinc for
strips and plates.
[0010] DE 30 07 850 C describes the use of a zinc alloy as a powder
for mechanical plating. In addition to improved corrosion
resistance, above all, a perfect adhesion of the coating to the
substrate is to be achieved. Thus, this is again a different use
from that of such alloys as constructional zinc for beams and
plates.
[0011] DE 914 785 describes a bearing alloy made of zinc, aluminum
and other components in which the content of copper and/or
manganese is to be about 1%. These alloys can be used as bearing
and kneading alloys. These functions are completely different from
the use of zinc alloys as constructional zinc for strips and
plates.
[0012] The object to provide strips and plates of alloyed zinc for
use as constructional zinc which meet even higher demands is now
achieved, above all, by adjusting the aluminum content to from 5 to
35% by weight, preferably from 5 to 20% by weight, especially from
8 to 15% by weight. Further improvements are achieved by
co-alloying from 0.002 to 0.04% by weight of indium and/or from
0.002 to 0.04% by weight of calcium and/or from 0.002 to 0.4% by
weight of titanium and/or from 0.05 to 0.8% by weight of manganese.
Copper, iron and lead should be contained therein only in such
amounts as are unavoidable as impurities of zinc and aluminum.
Further improvements of the properties are possible with from 3 to
100 ppm of boron, from 3 to 100 ppm of carbon, from 3 to 50 ppm of
magnesium, from 2 to 500 ppm of vanadium, from 2 to 500 ppm of
silicon and/or from 2 to 500 ppm of nickel.
[0013] The improved properties of the alloys used according to the
invention can be seen from comparative corrosion studies with the
salt spraying test according to DIN 500 21-ss (storing for 7 or 14
days), and with the condensed water/SO.sub.2 test according to DIN
50 018 KFW 0.2s (storage for 22 cycles). After the storage, the
mass changes and the optical appearance of the corrosion of the
sheets are established.
[0014] It was found that the plates and strips according to the
invention exhibit a clearly improved corrosion resistance in the
salt spraying test as compared to the previously used fine zinc
alloys, which is manifested by a corrosion rate which is reduced by
one power of ten. In the condensed water/SO.sub.2 test according to
DIN 50 018 KFW 0.2s, there was also found a clearly improved
corrosion resistance as compared to the previously used fine zinc
alloys.
[0015] Comparative studies in the salt spraying test according to
DIN 50 021-ss in comparison with fine zinc alloys I and II in
DE-A-195 45 487 have shown that the mass loss can be reduced by at
least another 80%. In the SO.sub.2 test according to DIN 50 018 KFW
0.2s, the mass loss decreases by at least another 70% as compared
to these alloys.
[0016] It is of particular importance that the risk of punctual
deep corrosion as a consequence of mistakes of building physics
and/or unprofessional laying is clearly reduced in the alloys
according to the invention, and that the loss of metal can be
minimized. Thus, the import of leached-out metals into the
environment is also clearly reduced. This is demanded, for example,
by the Dutch authorities.
[0017] The preferably co-alloyed elements indium, calcium, titanium
and manganese have an influence, above all, on the mechanical
properties, but they additionally improve the corrosion
behavior.
[0018] Particularly good results are achieved with alloys having an
aluminum content of from 5 to 20% by weight of aluminum, the range
of from 8 to 15% by weight of aluminum being particularly
preferred.
[0019] Impurities of more than 0.1% by weight of copper and of more
than 0.1% by weight of iron lead to deteriorated mechanical
properties and especially enhance intercrystalline corrosion. Thus,
these metals and other impurities should be present only in the
usual unavoidable amounts.
[0020] Although the contents of indium, calcium, titanium and
manganese can be increased in principle, this would only result in
an unnecessary increase in price of the material without noticeably
further improving the properties.
[0021] The strips and plates which can be used as constructional
zinc can be prepared by the usual casting-and-rolling process. In
principle, all zinc grades according to EN 1179 can be used, the
zinc grade Z1 being preferred because it contains relatively little
lead, iron and copper.
[0022] Aluminum as an alloy component is preferably employed in the
grades according to EN 576.
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