close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2108588

код для вставки
2,108,588
Patented : ‘Feb. 15, 1938
UNITED STATES PATENT OFFICE
2,108,588
PROCESS ' OF PRODUCING SHEETS FROM
CORROSION~RESISTANT FERROUS-BASE
ALLOYS COMBINING IMPROVED‘
STRENGH PROPERTIES WITH CORRO
SIOhl RESISTANCE’ .
Victor‘ B. Lawrence, Norristown, Pa., assignor
to Alan Wood Steel Company, a corporation oi’ ,
>
Pennsylvania
No Drawing. Application May 25, 1935,
'
Serial No. 23,520
6 Claims. ('01. 1411-12)
This invention relates to the production of that are obtainable by cold rolling and at the
same time either bene?cially a?fect, or at least
not materially decrease, the corrosion resistance
properties of the alloy. as compared with those
that would be exhibited by a similar alloy worked
make for ease oi’ fabrication by methods involv- L by the hot rolling process.
According to my invention a copper-contain
ing welding, bending and similar operations.
It has long been common'practice to cold roll ing iron or steel alloy, of the ferritic type and
of a suitable composition to exhibit resistance to
iron and steel to obtain increased strength.‘ How
10 ever, cold rolling has the disadvantage that‘, it corrosion and at the same time readily rollable
lowers the corrosion resistance of the metal. when heated, and in the iorm of a slab or billet‘
Therefore, cold rolling is not applied where it‘is of suitable thickness, is heated to a temperature
desired that the ?nished sheet or plate shall have above or within the upper critical range and then
a high resistance to corrosion, and, consequently, rolled while accelerating the cooling of the metal
15 it has not been practical to produce cold rolled ‘by applying water or any other cooling medium,
sheets and plates from special iron and steel this being continued until the metal has cooled
‘alloys designed by reason 01’ their‘ composition or quenched to below the critical range. The
rolled iron and steel sheets and plates character
ized by relatively high resistance to rust and cor
rosion, ‘and having high tensile strength and
5 ductility as well as other physical properties that
to have high corrosion resistance. In other
rolling may be continued after the temperature
twor‘dsfthe sacri?ce of corrosion resistance of is below the critical range, in this way combining
'20‘ these alloys has been such as to make it unat the e?ect of cold rolling and quenching and im '20
lftractive trommthe commercial standpoint to cold
roll them to obtain high- strength. IZl‘herefore,
parting ‘to the metal greater tensile and elastic
strength with less loss oi’ ductility to the piece
where it is desired to produce sheets and plates . than would result by either cold rolling . or
having both high corrosion resistance and high‘ quenching applied individually. The rolling car
strength, resort has been had to special iron and ried on after the metal is below the critical range
does not appear to adversely affect the corrosion
steel alloys combining to a greater or lesser ex
resistance properties of the metal.
“tent the properties of high strength and cor
rosion resistance when the alloy is formed into . I have found that the rolling operation is
- advantageously carried out in a conventional
sheets or plates by hot rolling.
three-high rolling mill through which the pieces
Steel sheets of high strength have been prb
duced by the alloying of ironwith hardening are passed to and fro. A tilting table is pro
elements-carbon, manganese, chromium, nickel, vided at each side of the mill to catch the pieces
as they are rolled and lii't'them into the return
molybdenum, etc., but the fabrication by weld
ing of such iron alloys has involved di?iculties pass. The starting materlal,—billet, slab, plate
‘which have made them commercially undesira- . or break-down—is brought-‘at the appropriate
ble, and ‘the maximumweldable limits of ferrous temperature from a furnace disposed convenient
alloys hardened by additions-cf one of the above ly near theentering side of the mill.‘ The rolls" '
are kept cool by means of water sprays which
elements, or combinations of these elementsI es
tablished by the present welding technique, are prevent change in shape of the rolls due to heat
too low to permit more than moderate increases ing and at the same time promoting the cooling 40
of thelpieces being passed, through the rolls.
in strength.
.
,
Summarizing the abovefsheets and light struc
tural shapes formed from iron _or steel alloy com
bining higher resistance to corrosion, high
strength, and good welding properties, have not
been available'at a reasonable cost of produc
tion.
-‘
.
'
I have found that by appropriate selection of
the iron or steel an
with respect to work
ability’ and resistance to corrosion, and con
ducting the rolling operation in the manner
hereinafter ' more particularly described, it is
possible to produce sheets, plates and other rela
tively thin'structural shapes having the high
55 strength and other desirable physical properties
The process can also be carried out on mills other
than the conventional three-high rolling mill,
for example, two-high or four high continuous
mills, providing the material is cooled and
quenched during the rolling operation by the
application of, water or other cooling medium.
The process is applicable to a wide range of
copper-containing iron and steel alloys of the
non-austenitic or ferritic type. One advantage 50
of the present invention resides in the fact that
relatively‘ cheap iron and steel alloys may be
so improved with respect to their strength and
other physical properties as to meet strength and
corrosion resistance speci?cations that hereto 55
2
'
2,108,588.
fore could only be met by resort to more expen
sive iron and steel alloys. A group of relatively
inexpensive corrosion resistant iron and steel al
.
quenching‘ should then be continued, the larger .
part of the further reduction occurring with the
steel in the Ac1-Ac3 range. However, it is pref-.
loys that are amenable to the process and can
erable to so conduct the operation as to insure
be formed into sheets and plates having rela
tively high strength without detrimental effect
that some further reduction must be e?ected
after the temperature of the metal has fallen be
low the AC1 range. In this way it is‘ insured that
there will not be any annealing effect which
on vtheir corrosion resistance, are those copper
containing iron and steel alloys in which the
carbon content is kept under 0.50%, the copper
10 is under 0.80%, and phosphorus is less than
‘would tend to nullify the results of the accel
erated cooling and rolling treatment. At the 10
same time, further improvement in the strength
0.10%. I have found, for example, that im
provement in strength values of the order noted properties of the sheet is brought about in this
below maybe obtained by rolling a copper-bear
?nal stage under conditions‘ approaching those
ing steel of the following analysis range under
of cold rolling but without the detrimental ef
fects on the "corrosion resistance of the product
the conditions of accelerated cooling hereinbe-_
15
fore
described:
8
>
.C---
'
'
that is characteristic’ of cold rolling.
‘
Percent
.._'__
Mn
0.1 —0.3 '
___
__
____ 0.30-0.70
SP-
Under 0.04
~
_
__,__
C11 __._..
_
_.._..
Elastic limit
25'
.os-o.1o
_ 0.35- .50
ultimaltf
lbs/sq. in. 1§8t_/'§g§‘in_
_
When starting with pieces that have already
been'brought down to a relatively thin cross
section by hot rolling, they may be brought to
the combined quenching and rolling operation 20
of the present invention at a temperature within
the A03 critical range. For example,lstarting
with steel sheets or break-downs that have been
hot rolled to 1%" and which it is desired to re-.
duce to sheets of 1%" thickness, the temperature 25
at t e beginning-'of-the combined quenching and
rolling operation may be about 1600” F. _
30
0
40
45
50
Ordinary liotrolled ....... _. ________ _-
' 33,000
saoocssom
Present process ______________________ __
70,000
‘ 90,000
While the invention has been described with
particular reference to the production of sheets,
it will be understood that bene?cial results may 30
and, what is particularly _ important, these .be obtained in producing other products of thin I ‘
values are obtainable without adversely affecting cross-section such as light plates and strips. In
the corrosion resistance of the alloy.
‘
fact, any structural shape that may be formed
Although the invention makes possible the sub
by rolling and having a cross-section of a sim- '
stitution of relatively inexpensive copper-con
ilar thinness as sheets and light plates is to be 35
taining iron and steel alloys for more expensive
considered as within the scope of the invention.
alloys that have heretofore been considered es
Except where the context indicates a more re
sential to obtain desired combinations of cor
stricted meaning, the term “sheet” as used in the
rosion resistance and strength, it will be under? speci?cation and appended claims is to be under
stood thatthis ‘does not mean necessarily thatvv stood as including plates and other structural
the more expensive ferrous-base copper-contain
shapes of thin cross-section.
I
ing alloys will be rendered uninteresting from
The term “slab” as used in the speci?cation
the commercial standpoint by reason of the im
and claims is to be understood as including not
provement in the properties 01' cheaper alloys only slabs as this term is applied in its more re
that is made possible by my process. On the stricted sense in the rolling industry but also. 45
contrary, my process makes it possible to so im .billets, ‘plates and sheets which have been pre-'- ;
prove the properties of. some of the more ex-' liminarily worked by hot rolling from the origi
pensive alloys ‘as to widen their field of useful-. nal cast ingots, and which are intended to be
ness. Commercially available copper-containing further reduced to bring them to ?nal dimension.
alloy ‘steels oi’ the territic type which oil’er this
50
I claim:
prospect are‘ those containing in‘ appropriate
1. The process of working and heat treating»
amounts or combinations, chromium, copper, corrosion resista'nt ‘copper-containing ferrous
manganese, molybdenum, ‘nickel, silicon, phos ' base
alloys of the ferritic type to produce struc
phorus or vanadium.
‘
‘
i
In carrying out the rolling operation the tem- '
perature at which the slab or other partially re
’ duced shape is brought to the rolls will vary
somewhat depending on the'thickness of the slab
tural shapes of thin cross-section having im
proved , physical
properties,
which comprises 55
heating a'copper-containing ferrous-base alloy
of corrosion resistance analysis and of thefere
ritic type' to a temperature at least approximat
ing the upper critical point, and then hot rolling
with accelerated cooling of the metal during the
rolling operation, and continuing said combined
and the thickness desired in the ?nished sheet
or ‘plate. The thickness of the slab brought to
the rollingoperation should also beconsidered in
relation to the temperature, the extent of the re . rolling and accelerated cooling 'until the tem
duction required and the time involved in e?ect
perature of the metal throughout its section has
, ing the reduction, so asto insure that a suitable
been brought below the lower critical range.
relation
is
maintained
between
the
rate
oi’
cool4
2. The‘process of producing structural shapes 65
65
ing of the material as it undergoes rolling and of thin cross-section with improved strength
60
' quenching and, the rate ofreduction to the de
sired thickness. In the case of heavier sheets,
properties from corrosion resistant copper-con
taining ferrous-base alloys of the ferritic type
v‘say, %"-?;" ‘in thickness, the slab, should be( without substantially impairing the corrosion re
70 heated to about 2000" R, or well above the Ac: sistance of the alloy, whichcomprises subjecting 70
critical range. Starting --with a slab of say a copper-containing ferrous-base alloy or cor
UAW-3” thick, reduction to about %" may be rosion resistance analysis and of the ferritic type
expected at the time the temperature, of the slab to hot rolling while accelerating the cooling of
or plate has fallen to the Ac: point, or around the metal by applying a liquid quenching medium
75 1'750n F. for a low carbon steel. Therolling and thereto, continuing said combined rolling and 75
3
quenching treatment until the temperature of
the metal throughout its section has been brought
below the lower critical range, and continuing
the rolling treatment to e?’ect further reduction
5 of the thickness and to improve the strength
properties of the rolled shape. ‘ .
ture at least approximating the upper critical
point, then simultaneously subjecting the heated '
slab to rollingand quenching, and so correlating
the initial temperature, the thickness of the slab
and the time and rate of rolling as to insure that
the temperature of the rolled product shall have
been brought‘below the lower critical range before
3. Process of producing sheets with improved
strength properties from corrosion resistant cop
the desired ?nal dimension is reached.
per-containing ferrous-base alloys of the ierritic
.5. Process of producing structural shapes of
10 type without detrlmentally aii’ecting the corro
thin cross-section with improved strength from 10
sion resistance of the alloy, which comprises sub
corrosion resistant copper-containing ferrous
Jecting a copper-containing ferrous-base alloy of base alloys of the ierritic type while. substantially
corrosion resistance analysis, containing not retaining the corrosion resistance‘ properties of
more than 0.5% carbon and of the ierritic type, 'the alloy, which comprises subjecting a copper
15 to hot rolling to produce a slab of desired thick , containing ferrous-base alloy of corrosion re 15
ness for the succeeding working and heat treat- }
ment, heating the slab to a temperature at least
approximating the'upper critical point, then sub
Jecting the thus heated slab to rolling while
' an accelerating the cooling hi the metal by applying
a quenching medium thereto during the rolling
operation, and continuing said combined rolling
and quenching treatment until the temperature
oi the metal throughout its section has been
brought below the lower critical range.
>
4, Process of producing sheets with improved
structural properties from corrosion resistant
copper-containing‘ ferrous-base alloys 01' the
. i'erritic type without detrimentally aii'ecting the
:20 corrosion resistance of the alloy, which comprises
subjecting a copper-containing ferrous-base alloy
oi corrosion resistance analysis, containing not
‘ more than'0.5% carbon and of the ,ferritic type
to hot rolling to produce a slab oi desired thick
v35 ness tor the succeeding working and heat treat
ment operations, heating the slab to a tempera
sistance analysis, containing not more than 0.5%
carbon and‘ oi the i’erritic type to hot rolling in
a three-high rolling mill while accelerating the
cooling~ oi the metal by applying sprays of water
thereto during the rolling operation, and con 20
tinuing said combined rolling and quenching
treatment until the temperature of 'the metal has
been brought below the lower critical range.
6. Process of producing sheets with improved
structural properties from copper-containing 25
ferrous-base alloys without detrimentally a?’ect-,
ing the corrosion resistance of the alloy, which
comprises heating a hot rolled slab of a copper
containing ferrous-base alloy of the ierritic type
to a temperature at least approximating the upper 30
critical point, then simultaneously subjecting
said slab to rolling and quenching and continuing
said combined rolling and quenching treatment
until the temperature of the rolled product has
been brought below the lower critical range;
35
‘
VICTOR H. LAWRENCE.
CERTIFICATE OF G-ORREGTI ON .
Patent n01, 2,108,588’.
February 15, 1958.
VICTOR H. LAWRENCE.
It.
hereby certified that error appears in the printed specification
of the above number-ed patent requiring correction as follows: Page 2, second
column, line 71,- claim 2, for the word "or" read of; and that the said Letters
Patent should-be read with this correction therein that the same ‘nay conform
to’ the record of the case in the Patent Office.- >'
= Signed and-sealed this 29th day of March, A. r n.’ 1958; -
i
> Henry van'rjtr'sdale,
Acting Commissioner of Patents.
3
quenching treatment until the temperature of
the metal throughout its section has been brought
below the lower critical range, and continuing
the rolling treatment to e?’ect further reduction
5 of the thickness and to improve the strength
properties of the rolled shape. ‘ .
ture at least approximating the upper critical
point, then simultaneously subjecting the heated '
slab to rollingand quenching, and so correlating
the initial temperature, the thickness of the slab
and the time and rate of rolling as to insure that
the temperature of the rolled product shall have
been brought‘below the lower critical range before
3. Process of producing sheets with improved
strength properties from corrosion resistant cop
the desired ?nal dimension is reached.
per-containing ferrous-base alloys of the ierritic
.5. Process of producing structural shapes of
10 type without detrlmentally aii’ecting the corro
thin cross-section with improved strength from 10
sion resistance of the alloy, which comprises sub
corrosion resistant copper-containing ferrous
Jecting a copper-containing ferrous-base alloy of base alloys of the ierritic type while. substantially
corrosion resistance analysis, containing not retaining the corrosion resistance‘ properties of
more than 0.5% carbon and of the ierritic type, 'the alloy, which comprises subjecting a copper
15 to hot rolling to produce a slab of desired thick , containing ferrous-base alloy of corrosion re 15
ness for the succeeding working and heat treat- }
ment, heating the slab to a temperature at least
approximating the'upper critical point, then sub
Jecting the thus heated slab to rolling while
' an accelerating the cooling hi the metal by applying
a quenching medium thereto during the rolling
operation, and continuing said combined rolling
and quenching treatment until the temperature
oi the metal throughout its section has been
brought below the lower critical range.
>
4, Process of producing sheets with improved
structural properties from corrosion resistant
copper-containing‘ ferrous-base alloys 01' the
. i'erritic type without detrimentally aii'ecting the
:20 corrosion resistance of the alloy, which comprises
subjecting a copper-containing ferrous-base alloy
oi corrosion resistance analysis, containing not
‘ more than'0.5% carbon and of the ,ferritic type
to hot rolling to produce a slab oi desired thick
v35 ness tor the succeeding working and heat treat
ment operations, heating the slab to a tempera
sistance analysis, containing not more than 0.5%
carbon and‘ oi the i’erritic type to hot rolling in
a three-high rolling mill while accelerating the
cooling~ oi the metal by applying sprays of water
thereto during the rolling operation, and con 20
tinuing said combined rolling and quenching
treatment until the temperature of 'the metal has
been brought below the lower critical range.
6. Process of producing sheets with improved
structural properties from copper-containing 25
ferrous-base alloys without detrimentally a?’ect-,
ing the corrosion resistance of the alloy, which
comprises heating a hot rolled slab of a copper
containing ferrous-base alloy of the ierritic type
to a temperature at least approximating the upper 30
critical point, then simultaneously subjecting
said slab to rolling and quenching and continuing
said combined rolling and quenching treatment
until the temperature of the rolled product has
been brought below the lower critical range;
35
‘
VICTOR H. LAWRENCE.
CERTIFICATE OF G-ORREGTI ON .
Patent n01, 2,108,588’.
February 15, 1958.
VICTOR H. LAWRENCE.
It.
hereby certified that error appears in the printed specification
of the above number-ed patent requiring correction as follows: Page 2, second
column, line 71,- claim 2, for the word "or" read of; and that the said Letters
Patent should-be read with this correction therein that the same ‘nay conform
to’ the record of the case in the Patent Office.- >'
= Signed and-sealed this 29th day of March, A. r n.’ 1958; -
i
> Henry van'rjtr'sdale,
Acting Commissioner of Patents.
Документ
Категория
Без категории
Просмотров
0
Размер файла
542 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа