US3725143A - Aging resistant cold rolled sheet products - Google Patents
Aging resistant cold rolled sheet products Download PDFInfo
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- US3725143A US3725143A US00112444A US3725143DA US3725143A US 3725143 A US3725143 A US 3725143A US 00112444 A US00112444 A US 00112444A US 3725143D A US3725143D A US 3725143DA US 3725143 A US3725143 A US 3725143A
- Authority
- US
- United States
- Prior art keywords
- steel
- aging
- boron
- nitrogen
- manganese
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000032683 aging Effects 0.000 title abstract description 42
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 68
- 229910052796 boron Inorganic materials 0.000 abstract description 48
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 abstract description 45
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 34
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 31
- 229910052760 oxygen Inorganic materials 0.000 abstract description 31
- 239000001301 oxygen Substances 0.000 abstract description 31
- 239000000203 mixture Substances 0.000 abstract description 27
- 229910052799 carbon Inorganic materials 0.000 abstract description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 19
- 229910052710 silicon Inorganic materials 0.000 abstract description 15
- 239000010703 silicon Substances 0.000 abstract description 15
- 229910052782 aluminium Inorganic materials 0.000 abstract description 12
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract description 12
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 abstract description 6
- 239000012535 impurity Substances 0.000 abstract description 5
- 238000012545 processing Methods 0.000 abstract description 5
- 238000009628 steelmaking Methods 0.000 abstract description 5
- 229910000831 Steel Inorganic materials 0.000 description 99
- 239000010959 steel Substances 0.000 description 99
- 239000011572 manganese Substances 0.000 description 28
- 239000000047 product Substances 0.000 description 27
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 25
- 229910052748 manganese Inorganic materials 0.000 description 25
- 238000000034 method Methods 0.000 description 18
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 14
- 238000005266 casting Methods 0.000 description 14
- 238000005098 hot rolling Methods 0.000 description 12
- 238000009749 continuous casting Methods 0.000 description 11
- 230000008569 process Effects 0.000 description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 9
- 238000007792 addition Methods 0.000 description 9
- 238000012360 testing method Methods 0.000 description 8
- 229910000616 Ferromanganese Inorganic materials 0.000 description 7
- 229910001327 Rimmed steel Inorganic materials 0.000 description 7
- 229910004534 SiMn Inorganic materials 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 description 7
- 229910000720 Silicomanganese Inorganic materials 0.000 description 6
- 238000000137 annealing Methods 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 229910015136 FeMn Inorganic materials 0.000 description 5
- 230000002411 adverse Effects 0.000 description 4
- 230000001627 detrimental effect Effects 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000005096 rolling process Methods 0.000 description 4
- 239000002893 slag Substances 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 229910052698 phosphorus Inorganic materials 0.000 description 3
- 239000011574 phosphorus Substances 0.000 description 3
- 230000002035 prolonged effect Effects 0.000 description 3
- 239000000161 steel melt Substances 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 229910001208 Crucible steel Inorganic materials 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 230000003679 aging effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 238000005097 cold rolling Methods 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 238000010079 rubber tapping Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- APRRQJCCBSJQOQ-UHFFFAOYSA-N 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid Chemical compound OS(=O)(=O)C1=CC(O)=C2C(N)=CC(S(O)(=O)=O)=CC2=C1 APRRQJCCBSJQOQ-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229910000532 Deoxidized steel Inorganic materials 0.000 description 1
- 229910005347 FeSi Inorganic materials 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 101100409194 Rattus norvegicus Ppargc1b gene Proteins 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- QFGIVKNKFPCKAW-UHFFFAOYSA-N [Mn].[C] Chemical compound [Mn].[C] QFGIVKNKFPCKAW-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000009751 slip forming Methods 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- -1 therefore Substances 0.000 description 1
- 239000005028 tinplate Substances 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0273—Final recrystallisation annealing
Definitions
- a steel composition capable of being continuously cast and further processed to produce drawing-quality sheet steel having Substantial resistance to aging comprising: 0.01-0.08% carbon, 0.20-0.60% manganese, 0.03-0.08% silicon, up to 0.015% aluminum, less than 0.01% boron and other usual steelmaking impurities such as nitrogen and oxygen. It is essential that sutficient boron be included to provide a boron to nitrogen ratio of 1.4 to 2.5 when the oxygen content exceeds 150 p.p.m., or a ratio of 1.0 to 1.4 when the oxygen content is less than 150 ppm. In further processing the steel to sheet products, it is essential that the hot rolled product be coiled at a temperature above 1100" F.
- rimmed steels are preferred because of their superior surface quality and high degree of ductility. It is well known in the art that rimmed steel ingots are produced by casting a low-carbon, non-deoxidized steel into an ingot mold, where the decreasing temperature, and resulting decrease in oxygen solubility, causes the released oxygen to react with dissolved carbon and violently evolve carbon monoxide gas. This violent gas evolution called rimming action causes the ingot to solidify with a high purity, dense surface or rim and exceptional cleanliness and ductility throughout.
- Rimmed steels do, however, have one serious disadvantage for some applications in that the steel products rolled therefrom are subject to a high degree of strain aging. That is to say, the temper-rolled steel undergoes a spontaneous increase in hardness and decrease in ductility upon prolonged storage even at room temperatures, which is primarily due to segregation of nitrogen. atoms to dislocations producing pinning of the dislocations by solute atoms. For those applications where prolonged storage or severe cold forming are expected, non-aging steels can be produced by casting the ingot with a steel that has been deoxidized with aluminum and/or titanium.
- This invention concerns our discovery of a unique steel composition which can be continuously cast to produce a non-aging or aging-resistant steel having exceptionally good quality for further processing to thin flat rolled steel products.
- the inventive concepts not only involve the critical control of steels composition, particularly a very critical balance between the boron, nitrogen and oxygen contents, but also the critical control of the hot-rolling finishing temperature, coiling temperature, and annealing temperature when further processing the steel to thin flat rolled products.
- An object of this invention is to provide a unique steel composition which can be continuously cast and further processed to produce non-aging or aging-resistant highquality thin fiat rolled steel products with surface quality equal to that of conventionally produced rimmed steel.
- Another object of this invention is to provide a unique steel composition which can be continuously cast and further processed to produce high-quality thin flat rolled steel products having improved aging-resistance.
- a further object of this invention is to provide a process for producing a non-aging drawing-quality sheet steel from a continuous cast steel slab.
- Still another object of this inventon is to provide a process for producing a drawing-quality sheet steel having enhanced resistance to aging.
- the composition of a molten steel is determined and adjusted to provide a composition substantially as described in US. "Pat. No. 3,412,781, supra, namely, 0.01 to 0.08% carbon, 0.20 to 0.60% manganese, 0.03 to 0.08% silicon andup to-0.0l aluminum.
- this composition will provide a steel melt which can be continuously cast to provide a slab having good mechanical properties and especially suited for fiat-rolling to sheet products, the sheet products being comparable-to those previously rolled from rimmed steel ingots.'As previously noted, however, this steel'is subject to aging, so that sheet products rolled therefrom are not suitedto prolonged storage.
- the present invention overcomes the. aging problem inthe steel by further adjusting the melt composition to contain a carefully controlled amount of boron not exceeding about 0.01%.
- the boron content must be 1.4 to 2.5 times the :nitrogen content, in weight relationship, in a conventional non-degassed steel; and on the other hand, must be 1.0 to about 1.4 times the nitrogen content, in weight relationship, in a steel which has been degassed to contain less than about 150 p.p.m. of oxygen.
- the continuous cast slabs, having the above composition must be heated to a temperature within the range 2100 to 2300 F., for hot rolling, as is the customary prior art procedure.
- the hot rolling finishing temperature be above 1500 F. and preferably within the range 1550 to 1650 F., and that the hot rolled steel be coiled at a temperature above 1100 F. and preferably 1150 to 1250 F. Thereafter, the steel may be pickled, and cold rolled in accordance with conventional mill practices.
- the carbon content of the melt should not be less than 0.01%, and preferably not less than 0.03%, because otherwise the oxygen content of the steel would be too high for continuous casting.
- the lining life in the steelmaking furnace would be significantly shortened if the carbon content of steels therein are below 0.01%.
- the carbon content should not exceed 0.08% to assure sufficient ductility in the final sheet product.
- the manganese and silicon ranges for the molten steel as noted above are preferred because of the synergistic effect of these amounts in preventing pinhole porosity of a steel whose carbon content is 0.01 to 0.08%.
- the oxygen content of the steel can be more easily estimated and controlled when manganese exceeds 0.20%.
- the amount of acid soluble aluminum in the steel is preferably not greater than 0.015% because larger amounts tend to cause the formation of excessive quanticold forming operations such as press forming or deep drawing.
- the boron content of our steel must not exceed about 0.01%.
- the mere adding of .a prescribed, amount of boron in the range of 0.001 to 0.010%. is not enough, however, to assure that aging properties will even be affected, since the steels boron content must further be very carefully controlled with respect to thesteels nitrogen content, andto some extent with respect to the oxygen content as well.
- the boron content must be from -1.4 to 2.5 times the nitrogen content.
- boron to nitrogen ratios above 2.5 Nevertheless, an upper limit 2.5 on the boron to nitrogen ratio was arbitrarily chosen because excessive amounts of boron, i.e., more than about 2.5 times nitrogen when the nitrogen content is within the normal range of 0.003 to 0.005, will cause the resulting sheet steel to be quite hard, having a substantially adverse effect on the formability of the sheet.
- the boron to nitrogen ratio is maintained within the more preferred range of 1.4 to 2.0, the resulting steel will have a ductility equal to or greater than comparable prior art steels.
- the minimum boron to nitrogen ratio of 1.4 is no longer applicable, and in fact, ratios below 1.4, i.e., about 1.0 to 1.4 are equally effective at improving aging resistance.
- boron to nitrogen ratios above about 1.4 are actually detrimental, causing proportionally greater hardness at ratios thereabove.
- the boron to nitrogen weight ratio should be from about 1.0 to 1.4. Less boron than about 1.0 times nitrogen content will become exceedingly less effective in promoting aging resistance, while boron in amounts exceeding about 1.4 times nitrogen will proportionally decrease product ductility.
- the standard basic oxygen furnace practice for making low carbon steel may be used without modification. However, it is frequently advantageous to modify the cus .tomary .BOP furnace practice by charging enough manganese to the furnace to obtain a residual manganese content of at least 0.1% in the furnace melt. It is essential that the residual manganese content in the furnace melt beat least 0.10% when the sulfur content of the iron supplied to the furnace is in a normal range of from about 0.025% to 0.050%, in order to keep the sulfur content in the furnace melt down to an acceptable amount not greater than 0.02%.
- Residual manganese contents of over 0.1% are obtained by the addition of a manganese ore to the furnace charge, or by the addition of hot metal (iron from the blast furnace) containing enough manganese to give the residual manganese content of at least 0.10%.
- the use of manganese ore is preferred, since high manganese hot metal usually contains so much phosphorus as to raise the quantity of phosphorus in the steel casting above acceptable limits.
- the use of manganese ore makes it possible to obtain the desired residual manganese content in the furnace melt without also obtaining an excessively high phosphorus content.
- Either a high grade or low grade manganese ore may be used.
- the amount of ore added is at least about 0.1% by weight of Mn, based on the total weight of the furnace charge. Generally larger quantities are required because a large part of the manganese is lost to the furnace slag.
- the temperature in the furnace is customarily held within the range of 2850 to 3000" Temperatures above 3000 F. are to be avoided because these high temperatures cause rapid deterioration of the furnace lining, resulting in the presence of excessive quantities of refractory oxide slag in the furnace melt.
- a large portion of the manganese content of the molten steel introduced into the mold is added after tapping of the furnace melt, because it is impractical to charge enough manganese to a basic oxygen process furnace to furnish the desired manganese content in view of the excessive losses of manganese to furnace slag.
- Manganese may be added in the ladle in the form of silicomanganese, high or medium carbon ferromanganese, or electrolytic 1 manganese.
- the addition of silicomanganese also supplies the entire quantity of silicon which must be added in order to bring the molten steel composition up to the desired silicon level of 0.03-0.08%.
- Customarily about 6 to 10 lbs. per ton of silicomanganese and about 2 to 4 lbs. per ton of medium carbon ferromanganese are added in order to supply the necessary manganese and silicon to the molten steel.
- medium carbon manganese either high carbon ferromanganese or electrolytic manganese may be added. Frequently the amounts of high carbon ferromanganese required are somewhat less than the amounts of medium carbon ferromanganese normally required, being only about 1 to 2 lbs. per ton in most instances.
- the silicomanganese and the ferromanganese are most conveniently added to the molten steel during the filling of the tapping ladle with the furnace melt obtained in the steelmaking furnace. Best results are obtained when the silicomanganese and ferromanganese are added durin the filling of the middle third of the ladle.
- boron In addition to manganese and silicon, it is frequently preferably, following the aluminum addition after the aluminum has gone into solution, but early enough to prevent the boron from rising in the steel and contacting the slag and thus becoming oxidized and losing its effectiveness.
- Any practical form of boron may be used, such as ferroboron, calcium boride, silicomanganese boron, and so on. If the steel is not to be degassed or vacuum treated so that normal oxygen contents exceeding 150 p.p.m. will be present, then as explained above, the boron addition should be sufiicient to provide a boron to nitrogen weight ratio of 1.4 to 2.5 and preferably 1.4 to 2.0.
- the boron addition should be made after degassing and should be suflicient to provide a boron to nitrogen ratio of about 1.0 to 1.4.
- the steel is then poured into the upper end of an open-ended tubular water cooled continuous casting mold. solidification of the steel is initiated in the mold. A casting having a solidified skin surrounding a molten metal core is withdrawn downwardly from the mold, as entire solidification is effected by means of water sprays located below the mold, as is conventional in the art.
- the slab When the slab has been suitably conditioned for hot rolling, if such conditioning is necessary, it is heated to a hot rolling temperature within the range 2100 F. to 23-00 F. according to conventional prior art practices. Thereafter the slab is hot rolled according to conventional practices, with the finishing temperature being of course within the austenitic range, i.e., above about 1500 F., and preferably within the range 1550 to 1650 F. To eifect the aging resistance properties of this invention it is essential that the hot rolled steel be coiled at a temperature above 1100 F. and preferably Within the range 1150 to 1250 F. Although the reason for this limit is not clearly understood, the final product does show large reductions in aging resistance at coiling temperatures below about 1100 F.
- the steel may be pickled and cold rolled in accordance with conventional prior art practices.
- the steel may be pickled in either HCl or H acid solution, and then cold reduced by 50 to 75%.
- HNX gas a nitrogen containing atmosphere
- the cold rolled sheet is temper rolled in accordance with conventional prior art practices.
- the resulting cold-rolled sheet steel product obtained by practicing the above invention will have mechanical properties equal to or superior to prior art aging-resistant sheet steels produced from ingot cast steels. Of most significance is the fact that the improved results are substantially more reproduceable than experiences with prior art processes.
- conventional aging as indicated by return of yield point elongation, can be reproduceably retarded for at least days. Strain-aging index values can readily be reproduced within the range 0 to 10%.
- the aging resistance properties can be maximized to virtually an nonaging characteristic, i.e., strain-aging index values of from 0 to about 2.0% if the preferred hot rolling finishing temperatures of from 1550 to 1650 F. and coiling temperatures of 1150 to 1250 F. are provided.
- this invention is equally applicable to ingot cast steels.
- this invention ofliers the further advantage of providing an aging resistant steel which can be produced by either ingot casting or continuous casting operations.
- the R (or plastic strain ratio in the longitudinal direction) was then calculated as the ratio of the true width strain to the true thickness strain as is well known in the art.
- Table I gives the results of the tests as well as the compositions of the heats.
- eighteen heats not containing boron were identically prepared, processed and tested, with the typical results thereof shown at the bottom of Table I.
- the improved strain-aging index provided by this invention is readily apparent.
- N on-boron treated heats (typical values) 18 heats Various 0. 030/0. 046 0. 36/0. 47 0. 026/0. 052 003/0. 009 N.A. 17 1. 1
- a method of producing thin flat rolled steel products having substantial aging-resistance comprising forming a steel melt consisting of 0.0l-0.08% carbon, 0.20- 0.60% manganese, 0.0*30.08% silicon, -0.004-0.015% aluminum with a balance of iron and other usual steelmaking impurities including oxygen and nitrogen; adding up to about 0.01% boron to the steel to provide a boron to nitrogen ratio of 1.4 to 2.5 when the oxygen content is more than about ppm.
- a flat rolled steel product characterized by good surface quality, good drawability and exceptional aging resistance consisting essentially of 0.010.08% carbon, 0.200.60% manganese, 0.03-0.08% silicon up to 0.015% aluminum, other usual impurities including nitrogen and oxygen, less than about 0.01% boron but sufficient to provide a boron to nitrogen ratio of from 1.4 to 2.5 when the oxygen content is more than about 150 p.p.m.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11244471A | 1971-02-03 | 1971-02-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3725143A true US3725143A (en) | 1973-04-03 |
Family
ID=22343932
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00112444A Expired - Lifetime US3725143A (en) | 1971-02-03 | 1971-02-03 | Aging resistant cold rolled sheet products |
Country Status (15)
Country | Link |
---|---|
US (1) | US3725143A (fr) |
JP (1) | JPS5134807B1 (fr) |
AT (1) | AT330228B (fr) |
AU (1) | AU458543B2 (fr) |
BE (1) | BE778759A (fr) |
BR (1) | BR7200574D0 (fr) |
CA (1) | CA968587A (fr) |
DE (1) | DE2204454A1 (fr) |
FR (1) | FR2124370B1 (fr) |
GB (1) | GB1384263A (fr) |
IT (1) | IT948999B (fr) |
NL (1) | NL7201435A (fr) |
PL (1) | PL83384B1 (fr) |
YU (1) | YU34717B (fr) |
ZA (1) | ZA72471B (fr) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3873381A (en) * | 1973-03-01 | 1975-03-25 | Armco Steel Corp | High permeability cube-on-edge oriented silicon steel and method of making it |
US3905842A (en) * | 1974-01-07 | 1975-09-16 | Gen Electric | Method of producing silicon-iron sheet material with boron addition and product |
US3905843A (en) * | 1974-01-02 | 1975-09-16 | Gen Electric | Method of producing silicon-iron sheet material with boron addition and product |
US3950191A (en) * | 1974-10-21 | 1976-04-13 | Kawasaki Steel Corporation | Cold rolled steel sheets having an excellent enamelability and a method for producing said cold rolled steel sheets |
US3957546A (en) * | 1974-09-16 | 1976-05-18 | General Electric Company | Method of producing oriented silicon-iron sheet material with boron and nitrogen additions |
US3988173A (en) * | 1972-04-03 | 1976-10-26 | Nippon Steel Corporation | Cold rolled steel sheet having excellent workability and method thereof |
US3988174A (en) * | 1972-04-03 | 1976-10-26 | Nippon Steel Corporation | Hot rolled steel sheet having excellent workability and method thereof |
US4001052A (en) * | 1971-09-30 | 1977-01-04 | Kawasaki Steel Corporation | Hot-rolled low-carbon steel strip with an excellent press-workability capable of forming smooth pressed surface and a method of making the same |
US4113517A (en) * | 1974-04-26 | 1978-09-12 | Nippon Kokan Kabushiki Kaisha | Method of making cold-reduced al-killed steel strip for press-forming by continuous casting and continuous annealing process |
US4168181A (en) * | 1977-12-12 | 1979-09-18 | Eastern Steelcasting, Division Of Sivaco Wire & Nail Company | Wire manufacture |
US4397699A (en) * | 1980-05-27 | 1983-08-09 | Nippon Steel Corporation | Process for producing deep-drawing cold rolled steel strip by continuous annealing |
US4410372A (en) * | 1981-06-10 | 1983-10-18 | Nippon Steel Corporation | Process for producing deep-drawing, non-ageing, cold rolled steel strips having excellent paint bake-hardenability by continuous annealing |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS58174551A (ja) * | 1982-04-03 | 1983-10-13 | Sumitomo Electric Ind Ltd | ボロン含有鋼およびその製造方法 |
FR2696421B1 (fr) * | 1992-10-05 | 1995-01-06 | Lorraine Laminage | Acier pour emballage à ouverture par rupture d'une ligne de moindre résistance. |
CN114107833A (zh) * | 2020-08-26 | 2022-03-01 | 上海梅山钢铁股份有限公司 | 抗拉强度320MPa级电池壳用冷轧钢板及其生产方法 |
-
1971
- 1971-02-03 US US00112444A patent/US3725143A/en not_active Expired - Lifetime
-
1972
- 1972-01-24 ZA ZA720471A patent/ZA72471B/xx unknown
- 1972-01-24 CA CA133,058A patent/CA968587A/en not_active Expired
- 1972-01-26 AU AU38338/72A patent/AU458543B2/en not_active Expired
- 1972-01-31 DE DE19722204454 patent/DE2204454A1/de active Pending
- 1972-01-31 BE BE778759A patent/BE778759A/fr unknown
- 1972-02-01 PL PL1972153211A patent/PL83384B1/pl unknown
- 1972-02-02 AT AT82272*#A patent/AT330228B/de not_active IP Right Cessation
- 1972-02-02 IT IT67315/72A patent/IT948999B/it active
- 1972-02-02 BR BR574/72*[A patent/BR7200574D0/pt unknown
- 1972-02-02 FR FR7203419A patent/FR2124370B1/fr not_active Expired
- 1972-02-03 YU YU255/72A patent/YU34717B/xx unknown
- 1972-02-03 NL NL7201435A patent/NL7201435A/xx unknown
- 1972-02-03 GB GB518172A patent/GB1384263A/en not_active Expired
- 1972-02-04 JP JP47012529A patent/JPS5134807B1/ja active Pending
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4001052A (en) * | 1971-09-30 | 1977-01-04 | Kawasaki Steel Corporation | Hot-rolled low-carbon steel strip with an excellent press-workability capable of forming smooth pressed surface and a method of making the same |
US3988173A (en) * | 1972-04-03 | 1976-10-26 | Nippon Steel Corporation | Cold rolled steel sheet having excellent workability and method thereof |
US3988174A (en) * | 1972-04-03 | 1976-10-26 | Nippon Steel Corporation | Hot rolled steel sheet having excellent workability and method thereof |
US3873381A (en) * | 1973-03-01 | 1975-03-25 | Armco Steel Corp | High permeability cube-on-edge oriented silicon steel and method of making it |
US3905843A (en) * | 1974-01-02 | 1975-09-16 | Gen Electric | Method of producing silicon-iron sheet material with boron addition and product |
US3905842A (en) * | 1974-01-07 | 1975-09-16 | Gen Electric | Method of producing silicon-iron sheet material with boron addition and product |
US4113517A (en) * | 1974-04-26 | 1978-09-12 | Nippon Kokan Kabushiki Kaisha | Method of making cold-reduced al-killed steel strip for press-forming by continuous casting and continuous annealing process |
US3957546A (en) * | 1974-09-16 | 1976-05-18 | General Electric Company | Method of producing oriented silicon-iron sheet material with boron and nitrogen additions |
US3950191A (en) * | 1974-10-21 | 1976-04-13 | Kawasaki Steel Corporation | Cold rolled steel sheets having an excellent enamelability and a method for producing said cold rolled steel sheets |
US4168181A (en) * | 1977-12-12 | 1979-09-18 | Eastern Steelcasting, Division Of Sivaco Wire & Nail Company | Wire manufacture |
US4397699A (en) * | 1980-05-27 | 1983-08-09 | Nippon Steel Corporation | Process for producing deep-drawing cold rolled steel strip by continuous annealing |
US4410372A (en) * | 1981-06-10 | 1983-10-18 | Nippon Steel Corporation | Process for producing deep-drawing, non-ageing, cold rolled steel strips having excellent paint bake-hardenability by continuous annealing |
Also Published As
Publication number | Publication date |
---|---|
GB1384263A (en) | 1975-02-19 |
ZA72471B (en) | 1972-09-27 |
CA968587A (en) | 1975-06-03 |
AT330228B (de) | 1976-06-25 |
FR2124370B1 (fr) | 1975-10-24 |
FR2124370A1 (fr) | 1972-09-22 |
DE2204454A1 (fr) | 1972-08-17 |
AU458543B2 (en) | 1975-02-27 |
NL7201435A (fr) | 1972-08-07 |
JPS5134807B1 (fr) | 1976-09-29 |
YU34717B (en) | 1979-12-31 |
ATA82272A (de) | 1975-09-15 |
IT948999B (it) | 1973-06-11 |
BR7200574D0 (pt) | 1973-05-15 |
YU25572A (en) | 1979-07-10 |
AU3833872A (en) | 1973-08-02 |
PL83384B1 (fr) | 1975-12-31 |
BE778759A (fr) | 1972-07-31 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: USX CORPORATION, A CORP. OF DE, STATELESS Free format text: MERGER;ASSIGNOR:UNITED STATES STEEL CORPORATION (MERGED INTO);REEL/FRAME:005060/0960 Effective date: 19880112 |