Nippon Steel & Sumikin Stainless Steel Corporation

Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Shunji Sakamoto

Shinichi Teraoka

Satoshi Nishimura

Akihiko Takahashi

Toshio Tanoue

Akira Usami

Nobuhiko Hiraide

Naoto Ono

Motohiro Okushima

Masuhiro Fukaya

Takashi Kusunoki

Satoshi Ito

Masayuki Abe

Kenji Kato

Masao Kikuchi

Kazuo Yamamoto

Michio Kaneko

Hiroshi Kihira

Hidekuni Murakami

Katsuhiko Kato

Tadashi Komori

Tomomi Murata

Yuji Koyama

Fumio Fudanoki

Hiroshi Urashima

An automotive member or a feed oil pipe includes: a member made of a ferritic stainless steel containing predetermined components containing 10.5% to 18.0% of Cr in mass %; a metal fitting made of an aluminized stainless steel sheet, the metal fitting being attached to the member; and a gap structure defined between the member and the metal fitting, the gap structure being exposed to a chloride environment, where the metal fitting has an Al-plating weight per unit area of 20 g/mor more and 150 g/mor less on a surface corresponding to a gap of the gap structure, and surfaces of the metal fitting and the non-aluminized member other than the gap are coated with a cation electrodeposition coating film having a thickness of 5 &#x3bc;m to 35 &#x3bc;m.

Inexpensive automotive member and feed oil pipe, exhibiting excellent salt corrosion resistance

An aspect of a ferritic stainless steel contains, by mass %: C: 0.03% or less; N: 0.03% or less; Si: more than 0.1% to 1% or less; Mn: 0.02% to 1.2%; Cr: 15% to 23%; Al: 0.002% to 0.5%; and either one or both of Nb and Ti, with the remainder being Fe and unavoidable impurities, wherein Expression (1) and Expression (2) illustrated below are satisfied, an oxide film is formed on a surface thereof, and the oxide film contains Cr, Si, Nb, Ti and Al in a total cationic fraction of 30% or more,8(C+N)+0.03&#x2266;Nb+Ti&#x2266;0.6&#x2003;&#x2003;(1)Si+Cr+Al+{Nb+Ti&#x2212;8(C+N)}&#x2267;15.5&#x2003;&#x2003;(2).

Ferritic stainless steel for biofuel supply system part, biofuel supply system part, ferritic stainless steel for exhaust heat recovery unit, and exhaust heat recovery unit

A fuel pipe which is inexpensive and is excellent in salt spray corrosion resistance, characterized by being comprised of a steel pipe member having as a material a ferritic stainless steel which contains, by mass %, C: 0.015% or less, Si: 0.01 to 0.50%, Mn: 0.01 to 0.50%, P: 0.050% or less, S: 0.010% or less, N: 0.015% or less, Al: 0.010 to 0.100%, and Cr: 13.0 to 18.0% and further, one or both of Ti: 0.03 to 0.30% and Nb: 0.03 to 0.30% and a metal fitting part, the metal fitting part and the steel pipe member having between them a crevice structure at the surface which the structure is exposed to a salt spray environment, an opening amount at a crevice part of the crevice structure being 0.2 mm or more, and an inside of the crevice part being coated by electrodeposition.

Fuel pipe and method of production of same

This ferritic stainless steel for components of an automobile exhaust system includes, in terms of percent by mass: C: &#x2266;0.015%; Si: 0.01% to 0.50%; Mn: 0.01% to 0.50%; P: &#x2266;0.050%; S: &#x2266;0.010%; N: &#x2266;0.015%; Al: 0.010% to 0.100%; Cr: 16.5% to 22.5%; Ni: 0.5% to 2.0%; and Sn: 0.01% to 0.50%, and further includes either one or both of Ti: 0.03% to 0.30% and Nb: 0.03% to 0.30%, with a remainder being Fe and inevitable impurities.

Ferrite-based stainless steel for use in components of automobile exhaust system

High strength dual-phase stainless steel sheet and steel strip which are excellent in corrosion resistance, the dual-phase stainless steel sheet and steel strip having a Vicker's hardness of 200HV or more and comprising, by mass %, C: 0.02 to 0.20%, Si: 0.10 to 2.0%, Mn: 0.20 to 2.0%, P: 0.040% or less, S: 0.010% or less, Cr: 15.0 to 18.0%, Ni: 0.5 to 4.0%, Sn: 0.05 to 0.50, N: 0.010 to 0.10%, and a balance of Fe and unavoidable impurities. The dual-phase stainless steel sheet and steel strip have a &#x3b3;p range of 60 to 95, and a ferrite and martensite dual-phase microstructure formed by being heated to the ferrite and austenite dual-phase region, then the austenite phase transforming to martenite in the subsequent cooling process, wherein &#x3b3;p=420C+470N+23Ni+7Mn+9Cu&#x2212;11.5Cr&#x2212;11.5Si&#x2212;12Mo&#x2212;7Sn&#x2212;49Ti&#x2212;47Nb&#x2212;52Al+189.

Dual-phase stainless steel sheet and steel strip and method of production

The present invention provides an optimum low-chromium stainless steel which prevents corrosion resistance degradation of a weld in the case of welding a low-chromium stainless steel utilizing martensite transformation in multiple passes (multipass), is excellent in weld intergranular corrosion resistance even in a severe corrosion environment, simultaneously avoids occurrence of preferential corrosion at the bond-bordering region of the weld heat-affected zone, and is also excellent in productivity, which low-chromium stainless steel comprises, in mass %, C: 0.015 to 0.025%, N: 0.008 to 0.014%, Si: 0.2 to 1.0%, Mn: 1.0 to 1.5%, P: 0.04% or less, S: 0.03% or less, Cr: 10 to 13%, Ni 0.2 to 1.5%, and Al: 0.005 to 0.1% or less, and further comprises Ti: 6&#xd7;(C %+N %) or greater and 0.25% or less, the balance being Fe and unavoidable impurities, and the contents of the elements satisfy specified expressions.

Low-chromium stainless steel excellent in corrosion resistance of weld

The present invention provides enamelware and a glaze improving the bondability between the steel substrate and enamel layer and superior in resistance to dew point corrosion by sulfuric acid and hydrochloric acid, that is, a steel substrate of a composition containing, by mass %, Cu: 0.05 to 0.5%, Si: 0.1 to 2.0%, Mn: 0.05 to 2.0%, P: 0.005 to 0.10%, and S: 0.005 to 0.1%, restricting C to C: 0.20% or less, and comprising a balance of Fe and unavoidable impurities on the surface of which an enamel layer of a thickness of 50 to 700 &#x3bc;m is provided. At that time, the content of Co oxides in the enamel layer is made, converted to Co, 0.01 to 10% and/or the content of Ni oxides is made, converted to Ni, 0.05 to 20% or the total content of Ni in the steel substrate and enamel layer is made 0.005 to 4.5% with respect to the total mass of the enamelware and/or the total content of Co is made 0.008 to 4.0% with respect to the total mass of the enamelware.

Enamelware and glaze

The present invention provides a steel material able to secure a superior corrosion resistance in a sulfuric acid dew point corrosive environment of exhaust gas obtained by burning high S-containing fuel, containing, by mass %, C: &#x2266;0.010%, Si: &#x2266;0.10%, Cu: 0.05 to 1.00%, P: &#x2266;0.030%, S: &#x2266;0.050%, and Al: &#x2266;0.10% and comprising a balance of Fe and unavoidable impurities. Further, this steel contains one type or two types or more of Sb, Sn, Cr, Mn, Mo, Ni, Nb, V, Ti, and B.

Steel excellent in resistance to sulfuric acid dew point corrosion

The present invention provides optimal low chromium stainless steel preventing the deterioration in corrosion resistance at the weld zone in the case of multipass welding, superior in grain boundary corrosion resistance of the weld zone even in a harsh corrosive environment, simultaneously free from preferential corrosion at the heat affected zones near weld fusion lines, and further superior in manufacturability, that is, low chromium stainless steel containing, by mass %, C: 0.03% or less, N: 0.004 to 0.02%, Si: 0.2 to 1%, Mn: over 1.5 to 2.5%, P: 0.04% or less, S: 0.03% or less, Cr: 10 to 15%, Ni: 0.2 to 3.0%, and Al: 0.005 to 0.1%, further containing Ti: 4&#xd7;(C %+N %) to 0.35%, and having a balance of Fe and unavoidable impurities, having a &#x3b3;p(%) expressed by a predetermined formula satisfying 80 or more, and satisfying Ti %&#xd7;N %&#x3c;0.004 as well.

Low chromium stainless steel superior in corrosion resistance of multipass welded heat affected zones and its method of production

The present invention provides a low alloy steel and a weld joint thereof excellent in hydrochloric acid corrosion resistance and sulfuric acid corrosion resistance, said low alloy steel containing, in mass, Here, said AI is given by the following expression,/10,000=0.0005+0.045&#xd7;Sb %&#x2212;C %&#xd7;Mo %,where % means mass %.

Low alloy steel and weld joint thereof excellent in corrosion resistance to hydrochloric acid and sulfuric acid

The present invention provides a fuel tank or a fuel pipe excellent particularly in the corrosion resistance of the outer surface in a salt damage environment, and is a fuel tank or a fuel pipe excellent in corrosion resistance characterized by: being formed by using a steel sheet or a steel pipe containing Cr of 9.0 to 25.0 mass % as the base material; on the outer surface thereof, having any one or more of welded portions, brazed portions and structurally gapped portions contacting components; and having one or more of metals, whose electrode potential in a 5%-NaCl aqueous solution at 30&#xb0; C. is &#x2212;0.4 V or less relative to a saturated calomel electrode, attached to at least a part or parts of said portion(s) of the outer surface in an electrically conductive manner.

Fuel tank or fuel pipe excellent in corrosion resistance and method for producing the same

The present invention provides: a fuel tank made of a ferritic stainless steel sheet having long lasting corrosion resistance under the environment of the fuel tank and excellent in formability when fabricating the fuel tank; more specifically, a fuel tank made of a ferritic stainless steel sheet containing 10 to 25 mass % of Cr and having an average r-value of 1.9 or larger, an r-value in-plane anisotropy &Dgr;r of 1.0 or smaller, and a total elongation of 30% or larger, having a plane intensity ratio I(111)/I(100) of 10 or larger, and having lubricant films on the surfaces of the steel sheet and a surface friction coefficient of 0.10 or less.

Fuel tank made of ferritic stainless steel

Method and apparatus for diagnosing degree of degradation of a coating film of a painted metal material by dividing the surface of the painted metal material into a number of small area zones, measuring impedance of the coating film at each of the zones through an AC impedance measuring technique, determining a statistic distribution and/or a two-dimensional distribution of impedance values measured at the individual zones to thereby determine the degree of degradation of the coating film of the painted metal material on the basis of the aforementioned distribution(s).

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Kitakyushu, Japan

Shunji Sakamoto