With Working At Or Below 120c Or Unspecified Cold Working Patents (Class 148/610)
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Patent number: 5606787Abstract: A continuous process line for converting hot rolled stainless steel strip to final gauge product is provided. The stainless steel strip has a scale formed on the surface thereof. The steel strip is introduced to a rolling mill to reduce the thickness of the hot rolled stainless steel to a final gauge thickness and tolerance. The rolling mill also cracks the scale on the surface of the final gauge thickness strip. An annealing section anneals the final gauge thickness strip received from the rolling mill. A pickling section pickles the annealed strip from the annealing section and removes the scale from the surface. Preferably, a molten salt bath section provided between the annealing section and the pickling section conditions the scale cracked in the cold rolling section and passes the conditioned stainless steel to the pickling section.Type: GrantFiled: September 14, 1995Date of Patent: March 4, 1997Assignee: J & L Specialty Steel, Inc.Inventor: Michael F. McGuire
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Patent number: 5571343Abstract: An austenitic stainless steel and a manufacturing process therefor are disclosed, in which, instead of the expensive Ni, there are added Cu as an austenite (.tau.) stabilizing element, and tiny amounts of Ti as a ferrite forming element and B for improvement of high temperature hot workability, so that the optimum Md.sub.30 temperature and the optimum delta-ferrite content can be controlled, thereby improving the formability, the season cracking resistance, the hot workability and the high temperature oxidation resistance, and reducing the surface defects during the hot rolling and saving the manufacturing cost by reducing the content of Ni. The austenitic stainless steel according to the present invention includes in weight %: less than 0.07% of C, less than 1.0% of Si, less than 2.0% of Mn, 16-18% of Cr, 6.0-8.0% of Ni, less than 0.005% of Al, less than 0.05% of P, less than 0.005% of S, less than 0.03% of Ti, less than 0.003% of B, less than 3.0% of Cu, less than 0.3% of Mo, less than 0.Type: GrantFiled: April 19, 1995Date of Patent: November 5, 1996Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & TechnologyInventors: Do Y. Ryoo, Yong H. Lee, Jae S. Park, Hyun C. Kim, Eung J. Kim
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Patent number: 5554235Abstract: A method and process line for producing cold-rolled stainless-steel or titanium-alloy strip from hot-rolled strip descales the hot-rolled strip by shot-blasting and/or brush-polishing and then cold-rolls the descaled strip. The cold-rolled strip, at its final thickness, is annealed and then pickled, all in a single continuous line.Type: GrantFiled: November 2, 1994Date of Patent: September 10, 1996Assignee: BWG Bergwerk-Und Walzwerk-Machinenbau GmbHInventors: Rolf Noe, Andreas Noe, Dieter Baukloh
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Patent number: 5505797Abstract: A method of producing a ferritic stainless steel strip having reduced intra-face anisotropy as well as excellent r value and anti-ridging characteristics. The method involves subjecting a ferritic stainless steel slab to a hot rolling step including rough rolling having at least one rough rolling pass and a finish rolling having at least one finish rolling pass, followed by a hot-rolled sheet annealing, pickling, cold rolling and finish annealing. At least one of the passes in the rough rolling is conducted with the rolling temperature between about 970.degree. C. to about 1150.degree. C., the friction coefficient between the rolls and the rolled material of about 0.3 or less, and the rolling reduction ratio between about 40 to about 75%.Type: GrantFiled: March 27, 1995Date of Patent: April 9, 1996Assignee: Kawasaki Steel CorporationInventors: Takeshi Yokota, Susumu Satoh, Takumi Ujiro, Fusao Togashi, Makoto Kobayashi, Shohei Kanari
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Patent number: 5496514Abstract: A fracture resistant stainless steel sheet comprises: non-metallic inclusions of Al.sub.2 O.sub.3, MnO, and SiO.sub.2 which inevitably exist in stainless steel; the non-metallic inclusions having a composition situated in a region defined by nine points in a phase diagram of a 3-component system of "Al.sub.2 O.sub.3 --MnO--SiO.sub.2 "; the stainless steel sheet having an 1.0% on-set stress of at least 1520 N/mm.sup.2 (155 kgf/mm.sup.2); the stainless steel sheet having an anisotropic difference of 1.0% on-set stress of 196 N/mm.sup.2 (20 kgf/mm.sup.2) or less; and the stainless steel sheet having a Erichsen number of at least 4.6 mm.A method for producing a high fracture resistant stainless steel sheet comprises the steps of: preparing a stainless steel strip; applying to the stainless steel strip a process of annealing--pickling --first cold rolling (CR.sub.1)--first intermediate annealing--second cold rolling (CR.sub.2)--second intermediate annealing--third cold rolling (CR.sub.Type: GrantFiled: February 1, 1994Date of Patent: March 5, 1996Assignee: NKK CorporationInventors: Katsuhisa Yamauchi, Hitoshi Misao, Tadashi Inoue, Tomoyoshi Okita
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Patent number: 5407493Abstract: A fracture resistant stainless steel sheet comprises: non-metallic inclusions of Al.sub.2 O.sub.3, MnO, and SiO.sub.2 which inevitably exist in stainless steel; the non-metallic inclusions having a composition situated in a region defined by nine points in a phase diagram of a 3-component system of "Al.sub.2 O.sub.3 -MnO-SiO.sub.2 "; the stainless steel sheet having an 1.0% on-set stress of at least 1520 N/mm.sup.2 (155 kgf/mm.sup.2); the stainless steel sheet having an anisotropic difference of 1.0% on-set stress of 196 N/mm.sup.2 (20 kgf/mm.sup.2) or less; and the stainless steel sheet having a punch test work load of at least 25 kgf.multidot.mm or more.A method for producing a high fracture resistant stainless steel sheet comprises the steps of: preparing a stainless steel strip; applying to the stainless steel strip a process of annealing--pickling --first cold rolling (CR.sub.1)--first intermediate annealing--second cold rolling (CR.sub.2)--second intermediate annealing--third cold rolling (CR.sub.Type: GrantFiled: January 31, 1994Date of Patent: April 18, 1995Assignee: NKK CorporationInventors: Katsuhisa Yamauchi, Hitoshi Misao, Tadashi Inoue, Tomoyoshi Okita
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Patent number: 5314549Abstract: A stainless steel sheet essentially consisting of: 0.01 to 0.2 wt. % C, 0.1 to 2 wt. % Si, 0.1 to 2 wt. % Mn, 4 to 11 wt. % Ni, 13 to 20 wt. % Cr, 0.01 to 0.2 wt. % N, 0.0005 to 0.0025 wt. % sol.Al, 0.002 to 0.01 wt. % O, 0.009 wt. % or less S, and the balance being Fe and inevitable impurities; the sheet containing 40 to 90% martensite; and the steel sheet having a 1400 N/mm.sup.2 or more tensile stress when a tensile strain is 1.0%. The invention also provides a method for producing a stainless steel sheet comprising the steps of: applying to the steel sheet a process of first cold rolling (CR.sub.1)--first intermediate annealing--second cold rolling (CR.sub.2)--second intermediate annealing--third cold rolling (CR.sub.3)--the final annealing--fourth cold rolling (CR.sub.4)--low temperature heat treatment; the first-, second- and third cold reduction ratio being 30% to 60%; the annealing temperatures in the first-, second- and final annealing being in the range of 950.degree. C. to 1100.degree. C.Type: GrantFiled: July 29, 1993Date of Patent: May 24, 1994Assignee: NKK CorporationInventors: Hitoshi Misao, Katsuhisa Yamauchi, Tadashi Inoue, Tomoyoshi Okita
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Patent number: 5284535Abstract: A method of manufacturing an austenitic stainless steel sheet having reduced minute surface concavities and convexties ropings and gloss unevenness and a manufacturing system for carrying out the same are provided. The method comprises (a) a casting process of casting a molten austenitic (.gamma.) stainless steel into a thin cast plate by a twin-roll thin plate casting method employing a pair of cooled rolls disposed opposite to each other, (b) a cooling process of cooling the cast thin plate in a single phase state of the .gamma. phase, (c) a cast plate in a dual phase state of the .delta. and .gamma. phase or a single phase state of the .delta. phase and then cooling the thin cast plate to restore the single phase state of the .gamma. phase, and (d) a cold-rolling process of cold-rolling the heat-treated thin cast plate.Type: GrantFiled: August 19, 1991Date of Patent: February 8, 1994Assignee: Nippon Steel CorporationInventors: Yoshiyuki Ueshima, Kenichi Miyazawa, Toshiaki Mizoguchi, Masayuki Abe
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Patent number: 5230752Abstract: A process and combination for ferritic stainless steel resisting corrosion in neutral or weakly acid chloride-containing media, being ductile and impact resistant, the compositions consisting essentially of 28.5 to 35% chromium, 3.5 to 5.5% molybdenum, 0.5 to 2% copper, less than 0.5% nickel, less than 0.4% manganese, less than 0.4% silicon, less than 0.030% carbon, less than 0.030% nitrogen, and of titanium and/or niobium between 0.10 to 0.60% where % Ti>0.2+4(% C)+3.4(% N) and/or % Nb>0.1+7.7(% C)+6.6(% N) is satisfied. The process if for production of steel strips of the above composition where the hot-rolled steel strip is tempered at 900 to 1200.degree. C., then subjected to a first cold rolling followed by an intermediate and final tempering at 900 to 1200.degree. C. after intermediate and final cold rollings.Type: GrantFiled: September 13, 1991Date of Patent: July 27, 1993Assignee: Ugine, Aciers de Chatillon et GueugnonInventors: Pierre Bourgain, Jean-Claude Bavay
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Patent number: 5217544Abstract: The present invention relates to a process for the production of a stainless steel with a high elastic limit and a high breaking load, with a martensite ferrite two-phase structure exhibiting good malleability and good abrasion resistance, in which the steel of the following weight composition:carbon lower than 0.10%chromium between 16 and 20%nickel between 0.2 and 2%manganese lower than 2%copper lower than 2%the remainder being iron and impurities which are inherent in the method of production, is subjected to a quenching after being raised to a temperature of between 800.degree. to 1200.degree. C., and at least one cold rolling to a content of more than 15%.The present invention also relates to a stainless steel obtained by this process.Type: GrantFiled: December 24, 1991Date of Patent: June 8, 1993Assignee: Ugine S.A.Inventors: Serge Baltenneck, Jean-Claude Charenton
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Patent number: 5181970Abstract: According to the present invention, a stainless steel thin strip and sheet having a superior surface gloss and high rusting resistance is produced by heating a continuous cast slab of ferritic or martensitic stainless steel containing 10 to 35% by weight of Cr at a temperature of 1100.degree. to 1300.degree. C. selected according to the Cr content in a combustion atmosphere having an oxygen concentration lower than 7% while adjusting the furnace staying time from preheating to extrusion to within 260 minutes, carrying out hot rolling while adjusting the rolling-finish temperature to a level higher than 900.degree. C., carrying out mechanical descaling by adding a grinding and descaling agent, such as iron sand, having a maximum particle size smaller than 400 .mu.Type: GrantFiled: June 13, 1990Date of Patent: January 26, 1993Assignee: Nippon Steel CorporationInventors: Masanori Ueda, Masamitsu Tsuchinaga, Teruo Iura, Shigeru Fujiwara
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Patent number: 5131960Abstract: By solution-annealing and water-quenching of a hot-rolled ferritic chromium steel comprising 0.03 to 0.07% carbon, not more than 1% silicon, not more than 1% manganese, 13 to 18% chromium, not more than 2% nickel, balance iron and impurities arising from melting, a ferritic martensitic microstructure can be obtained to achieve high strength, hardness and toughness.Type: GrantFiled: September 13, 1990Date of Patent: July 21, 1992Assignee: Rexnord Kette GmbH & Co. KGInventor: Ehrhard Kluge