Jfe Steel Corporation

Kawasaki Steel Corporation

Takumi Ujiro

Yasushi Kato

Susumu Satoh

Hiroki Ota

Osamu Furukimi

Junichiro Hirasawa

Kunio Fukuda

Tomohiro Ishii

Shin Ishikawa

Norimasa Hirata

Takeshi Yokota

Mitsuyuki Fujisawa

Tetsuyuki Nakamura

Masaaki Kohno

Makoto Kobayashi

Yoshimasa Funakawa

Yoshihiro Yazawa

Kazuhide Ishii

Koji Yamato

Shinsuke Ide

Yoshihiro Ozaki

Fusao Togashi

Katsuhisa Yamauchi

Atsutaka Honda

Susumu Sato

Yasuhiro Yamaguchi

Akito Mizutani

Takako Yamashita

Naoki Nishiyama

Noriko Makiishi

Masayuki Ohta

Shinji Yamazaki

Masahiro Yoshioka

Shohei Kanari

Toshihiro Kasamo

Katsuhiro Kobori

Hiroshi Yaginuma

Astushi Miyazaki

Masayuki Kasai

Shintaro Kumazawa

Hideaki Yamashita

Hideya Furusawa

Shuji Okada

A ferritic stainless steel excellent in corrosion resistance and conductivity and a method for manufacturing the same, the stainless steel having a chemical composition containing, by mass %, C: 0.001% or more and 0.05% or less, Si: 0.001% or more and 0.5% or less, Mn: 0.001% or more and 1.0% or less, Al: 0.001% or more and 0.5% or less, N: 0.001% or more and 0.05% or less, Cr; 17% or more and 23% or less, Mo: 0.1% or less and the balance being Fe and inevitable impurities and a passivation film on the surface of the stainless steel which is obtained by immersing the stainless steel in a solution for an immersion treatment, said solution mainly contains hydrofluoric acid or a liquid mixture of hydrofluoric acid and nitric acid.

Ferritic stainless steel excellent in corrosion resistance and conductivity and method for manufacturing the same, separator of proton-exchange membrane fuel cell and proton-exchange membrane fuel cell

Ferritic stainless steel is excellent in terms of both oxidation resistance and thermal fatigue resistance without adding expensive elements, such as Mo or W. The ferritic stainless steel, contains: C: 0.015 mass % or lower, Si: 1.0 mass % or lower, Mn: 1.0 mass % or lower, P: 0.04 mass % or lower, S: 0.010 mass % or lower, Cr: 16 to 23 mass % or lower, N: 0.015 mass % or lower, Nb: 0.3 to 0.65 mass %, Ti: 0.15 mass % or lower, Mo: 0.1 mass % or lower, W: 0.1 mass % or lower, Cu: 1.0 to 2.5 mass %, Al: 0.2 to 1.5 mass %, and the balance of Fe and inevitable impurities.

Heat-resistance ferritic stainless steel

A stainless steel foil contains, in percent by mass, 0.05% or less of C, 2.0% or less of Si, 1.0% or less of Mn, 0.003% or less of S, 0.05% or less of P, 25.0% to 35.0% of Cr, 0.05% to 0.30% of Ni, 3.0% to 10.0% of Al, 0.10% or less of N, 0.02% or less of Ti, 0.02% or less of Nb, 0.02% or less of Ta, 0.005% to 0.20% of Zr, 0.02% or less of Ce, 0.03% to 0.20% of REM excluding Ce, 0.5% to 6.0% in total of at least one of Mo and W, and the balance being Fe and incidental impurities.

Stainless steel foil and catalyst carrier for exhaust gas purifying device using the foil

An object is to provide a ferritic stainless steel having excellent oxidation resistance, while preventing a deterioration in formability, without adding expensive chemical elements such as Mo and W. Specifically, the ferritic stainless steel excellent in oxidation resistance having a chemical composition containing, by mass %, C: 0.015% or less, Si: 0.40% or more and 1.00% or less, Mn: 1.00% or less, P: 0.040% or less, S: 0.010% or less, Cr: 12.0% or more and 23.0% or less, N: 0.015% or less, Nb: 0.30% or more and 0.65% or less, Ti: 0.150% or less, Mo: 0.10% or less, W: 0.10% or less, Cu: less than 1.00%, Al: 0.20% or more and 1.00% or less, while the relationship Si&#x2267;Al is satisfied, and the balance being Fe and inevitable impurities.

Ferritic stainless steel excellent in oxidation resistance

A stainless steel for a fuel cell having good corrosion resistance throughout a wide potential range and a method for producing the same are provided. In particular, a coating having an intensity ratio [(OO/OH)/(Cr/Fe)] of 1.0 or more determined by X-ray photoelectron spectroscopy analysis is formed by performing an anodic electrolyzation treatment on a surface of a stainless steel in an electrolyte solution, the stainless steel containing 16% by mass or more of Cr and preferably having a composition that includes, in terms of percent by mass, C: 0.03% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.03% or less, Cr: 20 to 40%, at least one selected from Nb, Ti, and Zr, in total: 1.0% or less, and the balance being Fe and unavoidable impurities.

Stainless steel for fuel cell having good corrosion resistance and method for producing the same

A stainless steel sheet with excellent heat and corrosion resistances for a brake disk is provided. Specifically, in mass %, C: less than 0.10%, Si: 1.0% or less, Mn: 1.0 to 2.5%, P: 0.04% or less, S: 0.01% or less, Cr: more than 11.5% but not more than 15.0%, Ni: 0.1 to 1.0%, Al: 0.10% or less, Nb: more than 0.08% but not more than 0.6%, V: 0.02 to 0.3%, and N: more than 0.03% but not more than 0.10% are contained so that 0.03&#x2266;{C+N&#x2212;(13/93)Nb}&#x2266;0.10, (5Cr+10Si+15Mo+30Nb+50V&#x2212;9Ni&#x2212;5Mn&#x2212;3Cu&#x2212;225N&#x2212;270C)&#x2266;45, and {(14/50)V+(14/90)Nb}&#x3c;N (wherein Cr, Si, Mo, Nb, Ni, Mn, Cu, V, N, and C represent the contents (mass %) of the corresponding elements) are satisfied. With such a composition, the stainless steel sheet for a brake disk can be provided with both excellent heat resistance and excellent corrosion resistance after tempering.

Stainless steel sheet with excellent heat and corrosion resistances for brake disk

A brake disk excellent in temper softening resistance and toughness comprising, by mass, 0.1% or less of C, 1.0% or less of Si, 2.0% or less of Mn, 10.5% to 15.0% of Cr, and 0.1% or less of N, the remainder being Fe and unavoidable impurities, such that the following inequalities are satisfied: 5Cr+10Si+15Mo+30Nb&#x2212;9Ni&#x2212;5Mn&#x2212;3Cu&#x2212;225N&#x2212;270C&#x3c;45 (1) and 0.03&#x2266;{C+N&#x2212;(13/92)Nb}&#x2266;0.09 (2) wherein Cr, Si, Mo, Nb, Ni, Mn, Cu, N, and C each represent the content of the corresponding elements on a mass percent basis, and having a martensitic structure having prior-austenite grains with an average diameter of 8 to less than 15 &#x3bc;m.

Brake disk excellent in temper softening resistance and toughness

A steel sheet for a brake disc contains, on a mass percent basis, 0.02% or more and less than 0.10% C, 0.6% or less Si, more than 0.5% and 2.0% or less Mn, 0.06% or less P, 0.01% or less S, 0.05% or less Al, 11.0% to 13.5% Cr, 0.01% to 0.30% Ni, 0.10% to 0.60% Nb, 0.03% or more and less than 0.10% N, more than 0.0010% and 0.0060% or less B, and the balance being Fe and incidental impurities, and the steel sheet after quenching has a hardness of 32 HRC to 40 HRC on a Rockwell hardness scale C (HRC).

Steel sheet for brake disc, and brake disc

A stainless steel having good conductivity and ductility for use in a fuel cell separator is provided. In particular, the stainless steel has a composition of, in terms of % by mass, C: 0.01% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.02% or less, Cr: 20 to 40%, Mo: 4.0% or less, and at least one selected from Nb, Ti, and Zr: 0.05 to 0.60% in total, the balance being Fe and unavoidable impurities. At least one precipitate having an equivalent circle diameter of 0.1 &#x3bc;m or more is present per 100 &#x3bc;m, a ratio of a thickness t (&#x3bc;m) to a maximum diameter Dmax (&#x3bc;m) of the precipitates satisfies formula (1) below20&#x2266;max&#x2003;&#x2003;(1)and the thickness is 200 &#x3bc;m or less.

Stainless steel having good conductivity and ductility for use in fuel cell and method for producing the same

A ferritic stainless steel sheet for a water heater with excellent corrosion resistance of welds and toughness includes, in terms of mass %, 0.020% or less of C, 0.30 to 1.00% of Si, 1.00% or less of Mn, 0.040% or less of P, 0.010% or less of S, 20.0 to 28.0% of Cr, 0.6% or less of Ni, 0.03 to 0.15% of Al, 0.020% or less of N, 0.0020 to 0.0150% of O, 0.3 to 1.5% of Mo, 0.25 to 0.60% of Nb, and 0.05% or less of Ti, the remainder being composed of Fe and unavoidable impurities, and the ferritic stainless steel sheet satisfying the following formulae (1) and (2):25&#x2266;Cr+3.3Mo&#x2266;30&#x2003;&#x2003;(1)0.35&#x2266;Si+Al&#x2266;0.85&#x2003;&#x2003;(2)wherein Cr, Mo, Si, and Al represent the content (mass %) of Cr, Mo, Si, and Al, respectively.

Ferritic stainless steel sheet for water heater excellent in corrosion resistance at welded part and steel sheet toughness

A martensitic stainless steel, having high temper softening resistance, for disc brakes is provided. The martensitic stainless steel is not seriously softened by maintaining the steel at more than 600&#xb0; C. The steel has a hardness of 32 or more or a hardness of 30 or more in HRC after the steel is tempered at 650&#xb0; C. for one hour or tempered at 670&#xb0; C. for one hour, respectively. In particular, the martensitic stainless steel for disc brakes contains less than 0.050 mass % carbon, 1.0 mass % or less silicon, 2.0 mass % or less manganese, 0.04 mass % or less phosphorus, 0.010 mass % or less sulfur, 0.2 mass % or less aluminum, more than 11.5 mass % to 15.0 mass % chromium, 0.5 mass % to 2.0 mass % nickel, more than 0.50 mass % to 4.0 mass %. copper, more than 0.08 mass % to 0.6 mass % niobium, and less than 0.09 mass % nitrogen, the remainder being iron and unavoidable impurities. The carbon content, the nitrogen content, the niobium content, the chromium content, the silicon content, the nickel content, the manganese content, and the copper content satisfy the following inequalities (1) and (2):0.03&#x2266;[C]+[N]&#x2212;13/93&#xd7;[Nb]&#x2266;0.09 &#x2003;&#x2003;(1)5&#xd7;[Cr]+10&#xd7;[Si]+30&#xd7;[Nb]&#x2212;9&#xd7;[Ni]&#x2212;5&#xd7;[Mn]&#x2212;3&#xd7;[Cu]&#x2212;225&#xd7;[N]&#x2212;270&#xd7;[C]&#x2266;40 &#x2003;&#x2003;(2).

Martensitic stainless steel for disk brakes

A material for brake discs has temper softening resistance sufficient to maintain a hardness of HRC 31 or more after tempering at 700&#xb0; C. for one hour. The low-carbon martensitic chromium-containing steel contains 0.02% to 0.10% of carbon and 0.02% to 0.10% of nitrogen, the total content of carbon and nitrogen being 0.08% to 0.16%; 0.5% or less of silicon; 0.1% or less of aluminum; 0.3% to 3.0% of manganese; 10.5% to 13.5% of chromium; 0.05% to 0.60% of niobium and 0.15% to 0.80% of vanadium, the total content of niobium and vanadium being 0.25% to 0.95%; 0.02% to 2.0% of nickel; and 1.5% or less of copper, and has an Fp value (=&#x2212;230C+5Si&#x2212;5Mn&#x2212;6Cu+10Cr&#x2212;12Ni+32Nb+22V+l2Mo+8W+10Ta+40A1&#x2212;220N) of 80.0 to 96.0, a hardness after quenching of HRC 31 to 40, and a hardness after tempering at 700&#xb0; C. for one hour of HRC 31 or more.

Low-carbon martensitic chromium-containing steel

Disclosed is a ferritic stainless steel sheet which has excellent corrosion resistance against sulfuric acid in the high-temperature environment and shows less surface roughness at a bent part which is bent at 90&#xb0; or more. Specifically disclosed is a ferritic stainless steel sheet which has the following chemical composition: C: 0.02 mass % or less, Si: 0.05 to 0.8 mass %, Mn: 0.5 mass % or less, P: 0.04 mass % or less, S: 0.010 mass % or less, Al: 0.10 mass % or less, Cr: 20 to 24 mass % Cu: 0.3 to 0.8 mass %, Ni: 0.5 mass % or less, Nb: 0.20 to 0.55 mass %, and N: 0.02 mass % or less, with the remainder being Fe and unavoidable impurities; and which has such a structure that the maximum particle diameter of an S-containing precipitate is 5 &#x3bc;m or smaller.

Ferritic stainless steel sheet having superior sulfuric acid corrosion resistance and method for manufacturing the same

A ferritic stainless steel contains no expensive elements such as Mo and W, is free from the oxidation resistance loss caused by addition of Cu, and thereby has excellent levels of oxidation resistance (including water vapor oxidation resistance), thermal fatigue property, and high-temperature fatigue property. The ferritic stainless steel contains, in mass %, C at 0.015% or less, Si at 0.4 to 1.0%, Mn at 1.0% or less, P at 0.040% or less, S at 0.010% or less, Cr at 16 to 23%, Al at 0.2 to 1.0%, N at 0.015% or less, Cu at 1.0 to 2.5%, Nb at 0.3 to 0.65%, Ti at 0.5% or less, Mo at 0.1% or less, and W at 0.1% or less, the Si and the Al satisfying a relation Si (%)&#x2267;Al (%).

Ferritic stainless steel with excellent heat resistance

A ferritic stainless steel sheet for forming a raw material pipe for bellows pipe is excellent in formability and high-temperature properties (high-temperature salt corrosion resistance and high-temperature fatigue properties). Specifically, the ferritic stainless steel sheet for forming a raw material pipe for bellows pipe contains 0.015% by mass or less of C, 1.0% by mass or less of Si, 1.0% by mass or less of Mn, 0.04% by mass or less of P, 0.010% by mass or less of S, 11% to 19% by mass of Cr, 0.015% by mass or less of N, 0.15% by mass or less of Al, 1.25% to 2.5% by mass of Mo, 0.3% to 0.7% by mass of Nb, 0.0003% to 0.003% by mass of B, and the balance being Fe and incidental impurities. In the ferritic stainless steel sheet for forming a raw material pipe for bellows pipe, preferably, the average crystal grain diameter D of the steel sheet is 35 &#x3bc;m or less, and alternatively, the surface roughness Ra of the steel sheet is 0.40 &#x3bc;m or less.

Ferritic stainless steel sheet for raw material pipe for bellows pipe

Growing community of inventors

Chiba, Japan

Takumi Ujiro