With Working Patents (Class 148/609)
  • Patent number: 6113710
    Abstract: The present invention provides a ferritic stainless steel plate improved in the deep drawability and the anti-ridging property at deep drawing work and the production technique thereof. The practical construction of the present invention is a ferritic stainless steel plate containing from 0.001 to 0.015 wt. % C, not more than 1.0 wt. % Si, not more than 1.0 wt. % Mn, not more than 0.05 wt. % P, not more than 0.010 wt. % S, from 8 to 30 wt. % Cr, not more than 0.08 wt. % Al, from 0.005 to 0.015 wt. % N, not more than 0.0080 wt. % O, not more than 0.25 wt. % Ti with Ti/N.gtoreq.12, and from 0.05 to 0.10 wt. % (Nb+V) with V/Nb being from 2 to 5, and, if necessary, further containing one or more kinds selected from not more than 2.0 wt. % Mo, not more than 1.0 wt. % Ni, and not more than 1.0 wt. % Cu together with one or more kinds selected from from 0.0005 to 0.0030 wt. % B, from 0.0007 to 0.0030 wt. % Ca and from 0.0005 to 0.0030 wt. % Mg.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: September 5, 2000
    Assignee: Kawasaki Steel Corporation
    Inventors: Yasushi Kato, Takumi Ujiro, Susumu Satoh
  • Patent number: 6110421
    Abstract: A non-magnetic stainless steel, which contains stably a large amount of N, is excellent in the corrosion resistance and the strength and possible to obtain sound ingots and products, consists by weight percentage of C.ltoreq.0.08%, Si.ltoreq.0.50%, 13%.ltoreq.Mn.ltoreq.16%, P.ltoreq.0.040%, S.ltoreq.0.030%, 0.35%.ltoreq.Cu.ltoreq.1.00%, 2.50%.ltoreq.Ni.ltoreq.5.50%, 17.0%.ltoreq.Cr.ltoreq.19.0%, 0.5%.ltoreq.Mo+W.ltoreq.1.0%, 0.38%.ltoreq.N.ltoreq.0.60%, 0.ltoreq.0.0100%, sol-Al.ltoreq.0.05% and the balance Fe on condition that86(Ni+Cu).gtoreq.13Cr+19Mo+9W+2Mn.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: August 29, 2000
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Tetsuya Shimizu, Michio Okabe
  • Patent number: 6045633
    Abstract: A manufacturing mold base for plastic injection molds is formed from a martensitic stainless steel alloy comprising: about 0.03%-0.06% by weight C, about 1.0%-1.6% by weight Mn, about 0.01%-0.03% by weight P, about 0.06%-0.3% by weight S, about 0.25%-1.0% by weight Si, about 12.0%-14.0% by weight Cr, about 0.5%-1.3% by weight Cu, about 0.01%-0.1% by weight V, about 0.02%-0.08% by weight N, with the balance being Fe with trace amounts of ordinarily present elements.
    Type: Grant
    Filed: May 14, 1998
    Date of Patent: April 4, 2000
    Assignee: EDRO Engineering, Inc.
    Inventors: Eric D. Henn, Robert J. Friedrich, Michael A. Guscott
  • Patent number: 5986205
    Abstract: The stainless steel sheet useful as a substrate for non-single crystalline semiconductor solar cells has minute ripples with undulations along a rolling direction, and its surface roughness is controlled in the range of R.sub.z 0.3-1.4 .mu.m and R.sub.max 0.5-1.7 .mu.m. It is manufactured by finish cold rolling a stainless steel strip with a reduction ratio of at least 20% at a rolling speed of at least 400 m/min. using work rolls polished with abrasives of gage #100-#400 at a final pass, annealing the rolled strip in an open-air atmosphere and then electrolytically pickling the annealed strip in a nitric acid solution. Since minute ripples with undulations are formed on the surface of the stainless steel sheet, an energy conversion efficiency is increased by acceleration of scattering and multiple reflection of incident light rays projected into a non-single crystalline semiconductor layer.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: November 16, 1999
    Assignees: Nisshin Steel Co., Ltd., Canon Kabushiki Kaisha
    Inventors: Hisashi Matsune, Yasushi Nishimura, Takuji Okiyama, Masafumi Sano
  • Patent number: 5976282
    Abstract: An austenite stainless steel plate having both excellent surface brightness and superior corrosion resistance, without polishing after finish annealing and pickling for descaling of the strip. The steel plate contains Si 0.02 to 0.2 wt % together with Si oxides at 1.0 wt % or less in the surface layer part in the 10 .mu.m depth from the surface. The depth of the intergranular groove in the surface layer part is 0.1 .mu.m or more to 0.5 .mu.m or less. Furthermore, the steel plate contains Al of 0.005 wt % or less and 0 of 0.006 wt % or less. The Al oxides are contained at 0.1 wt % or less in the surface layer part in the 10 .mu.m depth from the surface.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: November 2, 1999
    Assignee: Kawasaki Steel Corporation
    Inventors: Kunio Fukuda, Yoshikazu Kawabata, Kazuhide Ishii, Susumu Sato
  • Patent number: 5868875
    Abstract: A ferritic non-ridging stainless steel and process therefor. A chromium alloyed steel melt is deoxidized with a sub-equilibrium amount of titanium and nitrogen and continuously cast into a strip or a slab or cast into an ingot having an as-cast fine equiaxed microstructure substantially free of columnar grains. The as-cast steel contains .ltoreq.0.010% Al, up to 0.08% C, 0.10-1.50% Mn, .ltoreq.0.05% N, .ltoreq.1.5% Si, 8-25% Cr, <2.0% Ni and is deoxidized with titanium, all percentages by weight, the balance Fe and residual elements. Preferably, the titanium is controlled so that (Ti/48)/?(C/12)+(N/14)!>1.5. A hot processed continuous sheet may be formed from a continuously cast slab without surface grinding, may be descaled, cold reduced to a final thickness and recrystallization annealed. An anneal prior to cold reduction is not required to obtain an annealed sheet essentially free of ridging.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: February 9, 1999
    Inventors: Eizo Yoshitake, Alan R. McKague
  • Patent number: 5849116
    Abstract: A steel material and a steel pipe each exhibiting an excellent corrosion resistance in an environment containing a wet carbon dioxide and a small amount of hydrogen sulfide are produced at low cost and with high productivity, a steel slab which contains, in wt %, 0.01 to 0.6% of Si, 0.02 to 1.8% of Mn, 7.5 to 14.0% of Cr, 1.5 to 4.0% of Cu and 0.005 to 0.1% of Al, which reduces C to not more than 0.02%, N to not more than 0.02%, P to not more than 0.025% and S to not more than 0.01%, and whose balance consists of Fe and unavoidable impurities, is heated to a temperature of 1,100.degree. to 1,300.degree. C., hot rolling is finished at a rolling finish temperature of not less than 800.degree. C. and a cumulative rolling reduction quantity at a temperature not more than 1,050.degree. C. is at least 65%, and cooling is carried out at a cooling rate of less than 0.02.degree. C./sec to at least 500.degree. C. so as to substantially convert the metallic structure to ferrite.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: December 15, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Akihiro Miyasaka, Masaaki Obata, Takashi Motoyoshi
  • Patent number: 5824264
    Abstract: A high-temperature austenitic stainless steel having improved weldability is disclosed. The steel consists essentially, by weight, of:C: 0.05%-0.15%, Si: less than 1.0%, Mn: 2.0% or less,P: 0.04% or less, S: 0.01% or less, Cr: 20%-30%,Ni: 10%-15%, N: 0.10%-0.30%,B: 0.0010%-0.01%,one or two of La and Ce: 0.01%-0.10% in total,Al: 0.01%-0.20%, anda balance of Fe and incidental impurities, wherein the contents of N and Al satisfy the following inequality:% N+2.times.% Al.ltoreq.0.500%and the value for Ni balance (Ni bal.) of the steel calculated by the following formula is in the range of from -1.0% to +3.0%:Ni bal. (%)=% Ni+0.5.times.% Mn+30.times.(% C+% N)-1.1.times.(% Cr+1.5.times.% Si)+8.2.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: October 20, 1998
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Hideki Uno, Yoshitaka Nishiyama, Yoshiatsu Sawaragi, Nobuo Otsuka, Kazuhiro Ogawa, Toshiro Anraku
  • Patent number: 5779820
    Abstract: The present invention relates to a process for producing a ferritic stainless steel having an improved corrosion resistance, and especially resistance to intergranular corrosion and to pitting corrosion. The steel is subjected, in a first phase, to cooling at a rate of between 400.degree. C. and 600.degree. C./hour down to a temperature of 900.degree. C. and then, in a second phase, to rapid cooling at a rate of between 1200.degree. C. and 1400.degree. C./h.
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: July 14, 1998
    Assignee: Usinor Sacilor
    Inventors: Jean-Michel Hauser, Pascale Haudrechy
  • Patent number: 5733387
    Abstract: A duplex stainless steel consisting of a ferrite phase and an austenite phase is disclosed which is superior in the hot ductility, the high temperature oxidation resistance, the corrosion resistance and the impact toughness. The duplex stainless steel is applied to marine facility and the like. The duplex stainless steel which consists of a ferrite phase and an austenite phase is composed of in weight %: less than 0.03% of C, less than 1.0% of Si, less than 2.0% of Mn, less than 0.04% of P, less than 0.004% of S, less than 2.0% of Cu, 5.0-8.0% of Ni, 22-27% of Cr, 1.0-2.0% of Mo, 2.0-5.0% of W, and 0.13-0.30% of N. Or there are further added one or two elements selected from a group consisting of: less than 0.03% of Ca, less than 0.1% of Ce, less than 0.005% of B and 0.5% of Ti. Further, the ratio (Cr.sub.eq /Ni.sub.eq) of the Cr equivalent (Cr.sub.eq) to the Ni equivalent (Ni.sub.eq) is 2.2-3.0. Further, the weight ratio (W/Mo) of the W to Mo is 2.6-3.4.
    Type: Grant
    Filed: February 4, 1997
    Date of Patent: March 31, 1998
    Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & Technology
    Inventors: Yong Deuk Lee, Kwang Tae Kim, Bong Un Kim, Yong Heon Lee
  • Patent number: 5626694
    Abstract: This invention relates to a process for the production of stainless steel sheets and proposes a process for the production of stainless steel sheets having a more excellent corrosion resistance as compared with the conventional one without trimming the steel sheet surface after annealing-pickling by preventing the chapping of steel sheet surface created in the production of present stainless steel sheet, particularly stainless steel sheets having extreme-low amounts of C, S, O.For this purpose, according to the invention, a starting material of stainless steel containing C: not more than 0.01 wt %, S: not more than 0.005 wt % and O: not more than 0.005 wt % is subjected to a hot rolling at a draft below 830.degree. C. of not less than 30%, cooled at a cooling rate of not less than 25.degree. C. sec, coiled below 650.degree. C. and then annealed and pickled.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: May 6, 1997
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoshikazu Kawabata, Susumu Satoh, Mitsuyuki Fujisawa, Kunio Fukuda
  • Patent number: 5565167
    Abstract: A stainless steel excellent in fused-salt corrosion resistance having a composition specified in weight per cent including not more than 0.1% of C, not more than 2.0% of Mn, not less than 7.5% and less than 15.0% of Ni, 14.0-20.0% of Cr, more than 0.2% and not more than 4.0% of Si, and 1.0-4.0% of Al, and in some cases also including one or more of not more than 3.0% of Cu, not more than 3.0% of Mo, not more than 1.0% of Ti, not more than 1.0% of Zr, not more than 0.5% Y, and not more than 0.5% of REM, and satisfying the relationship Si%/Al%.ltoreq.1.0, the balance being Fe and unavoidable impurities.
    Type: Grant
    Filed: July 10, 1995
    Date of Patent: October 15, 1996
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Nobukazu Fujimoto, Naoto Hiramatsu, Yoshihiro Uematsu
  • Patent number: 5492575
    Abstract: To produce a thin strip having a high cast strip toughness from a thin cast strip of a Cr-stainless steel containing Nb, Ti, and Al in an amount of 0.05% or more, a process includes the steps of: casting a thin cast strip of a Cr-stainless steel having a thickness of 10 mm or less, the steel containing 13-25 wt % of Cr, 0.05-1 wt % of one or more of Nb, Ti, Al and V in terms of a total amount, 0.03 wt % or less of C, 0.03 wt % or less of N, and 0.3-3.0 wt % of Mo in accordance with need, and having a .gamma.p value of 0% or less; hot-rolling the thin cast strip in a temperature range of from 1150.degree. to 950.degree. C. at a reduction in thickness of 5 to 50% to form a thin strip; either slowly cooling the thin strip at a rate of 20.degree. C./sec or less or holding the thin strip for 5 sec or more, in a temperature range of from 1150.degree. to 950.degree. C.; and then coiling the thin strip at a temperature lower than 700.degree. C..gamma.p(%)=420C+470N+23Ni+9Cu+7Mn-11.5Cr-11.
    Type: Grant
    Filed: September 14, 1994
    Date of Patent: February 20, 1996
    Assignee: Nippon Steel Corporation
    Inventors: Shinichi Teraoka, Takehisa Mizunuma, Takanori Nakazawa, Yuichi Satoh
  • Patent number: 5462615
    Abstract: Disclosed is a process for producing seamless steel pipes or flat products (strip or sheet) for pipes or vessels which are intended for the conveyance, transport or processing of gaseous or liquid hydrocarbons containing CO.sub.2 and water and possibly small proportions of H.sub.2 S and are resistant to stress crack corrosion and have good welding properties at the same time and a 0.2-percent elongation limit of at least 450 N/mm.sup.2. The process uses a nickel-containing steel of the following composition (percent by weight): min. 0.015% C, 0.15-0.50% Si, max. 2.00% Mn, max. 0.020% P, max. 0.003% S, 12.0-13.8% Cr, 0.002-0.02% N, 0.01-0.05% Nb, remainder iron and usual impurities. It is presently suggested that the nickel content is limited to a maximum of 0.25%, the manganese content amounts to at least 1.0%, the carbon content is limited to 0.035%, and 0.01 to 1.2% molybdenum is contained as additional alloying component.
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: October 31, 1995
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Ingo Von Hagen, Rolf Popperling, Hubertus Schlerkmann, Ulrike Zeislmair
  • Patent number: 5340415
    Abstract: A heat-resistant ferritic stainless steel plate or foil having improved toughness as well as workability is disclosed, which consists essentially of:C: not larger than 0.020%,N: not larger than 0.020%,wherein,C(%)+N(%): not larger than 0.030%,Si: not larger than 1.0%,Mn: not larger than 1.0%,orone or more of Si: larger than 1.0% but not larger than 5.0% and Mn: larger than 1.0% but not larger than 2.0%,Cr: 9.0-35.0%,Al: 3.0-8.0%,Y: 0.010-0.10%,Ti: 0.010-0.10%,Mo: 0-5.0%,Fe and incidental impurities: balance,and which is manufactured by cooling the hot-rolled steel plate at a cooling rate of 20.degree. C./sec- or higher immediately after hot rolling, coiling the hot-rolled steel plate at a temperature of 400.degree. C. or lower, and preferably cold rolling the resulting hot-rolled steel plate until the thickness thereof reaches 50 micrometers or less, and applying Al vapor deposition to both sides of the thus-obtained foil to a thickness of 0.2-4.0 micrometers.
    Type: Grant
    Filed: June 1, 1993
    Date of Patent: August 23, 1994
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Masao Koike, Akihito Yamagishi, Katsuhiko Maruyama, Shusuke Kakuchi
  • Patent number: 5327634
    Abstract: Process for improving the elasticity of a ski edge made of corrosion-resistant martensitic chrome steel, consisting of pre-stretching the edge, and for the manufacture of a ski incorporating edges so produced.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: July 12, 1994
    Assignee: Salomon S.A.
    Inventor: Yves Gagneux
  • Patent number: 5269856
    Abstract: A high strength steel belt having an excellent flatness and a duplex structure of austenite and martensite has been prepared by a process which comprises providing a cold rolled or cold rolled and annealed strip of a martensitic structure from low carbon martensitic stainless steel containing from 10 to 17% by weight of Cr and having a carbon content of not exceeding 0.15% by weight, connecting ends of the strip or ends of a plate cut from said strip to provide an endless belt, causing the endless belt to circularly move between rolls under tension and to pass through a heating furnace where the belt is heated to a temperature within a range from (As point of the steel+30.degree. C.) to Af point of the steel and not higher than 900.degree. C. so that a part of the martensitic phase may be changed to a reversed austenitic phase and a desired surface flatness may be obtained after cooling.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: December 14, 1993
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Takashi Igawa, Yoshihiro Uematsu, Toshihiko Takemoto
  • Patent number: 5232520
    Abstract: A high strength martensitic stainless steel having superior anti-fatigue characteristics when used in a corrosive or erosive environment. The steel has a proof strength of 80 to 110 kg/mm.sup.2 and a composition containing specified amounts of carbon, silicon, manganese, chromium, nickel, molybdenum, vanadium, and nitrogen, the balance being substantially iron and incidental inclusions. The contents of the additives are such that a nickel equivalent Nieq given by the following Formula (1) ranges between 10.5 and 12.9 wt. %:Nieq=[Ni]+[Mn]+0.5[Cr]+0.3 [Si]+[Mo] (1)where, [Ni], [Mn], [Cr], [Si], and [Mo], respectively represent the contents of Ni, Mn, Cr, Si, and Mo, respectively. The steel may also contain niobium or copper. The steel is produced by a process which includes a hot work and a subsequent cooling at a specific cooling rate to a specific temperature range.
    Type: Grant
    Filed: January 14, 1992
    Date of Patent: August 3, 1993
    Assignee: Kawasaki Steel Corporation
    Inventors: Yutaka Oka, Shigeto Matsumoto, Kiyoshi Uchida
  • Patent number: 5152848
    Abstract: A high toughness ferritic stainless steel having the excellent cold workability and the excellent heading workability suitable for the plastic working of screws, which consists essentially of, by weight percentage, C.ltoreq.0.03%, P.ltoreq.0.040%, S.ltoreq.0.010%, Si.ltoreq.1.0%, Mn.ltoreq.1.0%, 11.5%.ltoreq.Cr.ltoreq.22.0%, 0.05%.ltoreq.Nb.ltoreq.0.80%, N.ltoreq.0.025%, if necessary at least one selected from 0.2%.ltoreq.Cu.ltoreq.1.0%, 0.01.ltoreq.Mo.ltoreq.2.00%, 0.020%.ltoreq.Ni.ltoreq.1.50% and the balance being Fe and inevitable impurities, and the number of inclusions larger than 20 .mu.m amoung inclusions composed of carbo-nitrides of Nb, Ti and/or Zr in the steel is not more than 20. In the production of the high toughness ferritic stainless steel, the rolling material having the above-mentioned chemical compositions is heated to 1200.degree. C. or above at the rod rolling.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: October 6, 1992
    Assignee: Daido Tokushuko K.K.
    Inventor: Hideyuki Ohma