Jfe Steel Corporation

Kawasaki Steel Corporation

Yoshihiro Ozaki

Osamu Furukimi

Mineo Muraki

Yoshihiro Yazawa

Yasushi Kato

Kunio Fukuda

Takumi Ujiro

Masaki Kawano

Atsuhito Honda

Yukihiro Baba

Susumu Satoh

Atsushi Miyazaki

Junichiro Hirasawa

Akio Fujita

Norimasa Hirata

Takaaki Iguchi

Toshihiro Kasamo

Setsuo Kakihara

Atushi Miyazaki

Yasushi Katoh

Toshimitsu Nagaya

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 ferritic stainless steel sheet for use in raw material pipes for forming bellows pipes has excellent formability. More specifically, the ferritic stainless steel sheet contains 10 % to 25 % by mass of Cr and has a yield stress in the range of 300 to 450 MPa and the product of the yield stress and the uniform elongation properties of at least 5200 (MPa&#xb7;%). Preferably, the ferritic stainless steel sheet for use in raw material pipes for forming bellows pipes has an average crystal grain size D of 35 &#x3bc;m or less or a surface roughness of 0.40 &#x3bc;m or less as determined by Ra.

Ferritic stainless steel sheet for use in raw material pipe for forming bellows pipe

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

A ferritic stainless steel sheet contains abut 0.01 percent by mass or less of carbon; about 1.0 percent by mass or less of silicon; about 1.5 percent by mass or less of manganese; about 11 to about 23 percent by mass of chromium; about 0.06 percent by mass or less of phosphorous; about 0.03 percent by mass or less of sulfur; about 1.0 percent by mass or less of aluminum; about 0.04 percent by mass or less of nitrogen; about 0.0005 to about 0.01 percent by mass of boron; about 0.3 percent by mass or less of vanadium; about 0.8 percent by mass or less of niobium and/or about 1.0 percent by mass or less of titanium wherein 18&#x2266;Nb/(C+N)+2(Ti/(C+N))&#x2266;60; and the balance being iron and unavoidable impurities. The average crystal grain diameter is about 40 &#x3bc;m or less and the average surface roughness is about 0.3 &#x3bc;m or less.

Method of making ferritic stainless steel sheet having excellent deep-drawability and brittle resistance to secondary processing

A ferritic stainless steel sheet for use in automobile fuel tanks and fuel pipes having smooth surface and resistance to organic acid is provided. The sheet contains, by mass, not more than about 0.1% C, not more than about 1.0 Si, not more than about 1.5% Mn, not more than about 0.06% P, not more than about 0.03% S, about 11% to about 23% Cr, not more than about 2.0% Ni, about 0.5% to about 3.0% Mo, not more than about 1.0% Al, not more than about 0.04% N, at least one of not more than about 0.8% Nb and not more than about 1.0% Ti, and the balance being Fe and unavoidable impurities, satisfying the relationship: 18&#x2266;Nb/(C+N)+2Ti/(C+N)&#x2266;60, wherein C, N, Nb, and Ti in the relationship represent the C, N, Nb, and Ti contents by mass percent, respectively. A process for making the same is also provided.

Ferritic stainless steel sheet with excellent workability and method for making the same

Ferritic stainless steel sheet having excellent deep-drawability and brittle resistance to secondary processing and method for making the same

A martensitic stainless steel sheet which is hard to be softened by tempering caused by heating during the use of a disk brake, can maintain the predetermined hardness, and has excellent punching workability, bending workability before quenching, and a particularly small shear drop, and in which a predetermined hardness after quenching is constantly achieved, in a low carbon martensitic stainless steel sheet used only after quenching. Specifically, the sheet contains, on the basis of mass percent, 0.030% to 0.100% C; 0.50% or less of Si; 1.00% to 2.50% Mn; more than 10.00% to 15.00% Cr; at least one selected from the group consisting of 0.01% to 0.50% Ti, 0.01% to 0.50% V, 0.01% to 1.00% Nb, and 0.01% to 1.00% Zr; N in an amount defined by the following expression, N: 0.005% to (Ti+V)&#xd7;14/50+(Nb+Zr)&#xd7;14/90; and the balance being Fe and incidental impurities.

Low carbon martensitic stainless steel and method for production thereof

A ferritic stainless steel sheet for fuel tanks and fuel pipes comprises, by mass percent, about 0.1% or less of C; about 1.0% or less of Si; about 1.5% or less of Mn; about 0.06% or less of P; about 0.03% or less of S; about 1.0% or less of Al; about 11% to about 20% Cr; about 2.0% or less of Ni; about 0.5% to about 3.0% Mo; about 0.02% to about 1.0% V; about 0.04% or less of N; at least one of about 0.01% to about 0.8% Nb and about 0.01% to about 1.0% Ti; and the balance being Fe and incidental impurities. The ferritic stainless steel sheet is produced by rough-rolling a slab having the above composition; hot-rolling the rough-rolled sheet under a linear pressure of at least about 3.5 MN/m at a final pass in the finish rolling; cold-rolling the hot-rolled sheet at a gross reduction rate of at least about 75%; and annealing the cold-rolled sheet. The cold-rolling step includes one rolling stage or at least two rolling stages including intermediate annealing.

Ferritic stainless steel sheet for fuel tank and fuel pipe

A ferritic stainless steel sheet for use in automobile fuel tanks and fuel pipes having smooth surface and resistance to organic acid is provided. The sheet contains, by mass, not more than about 0.1% C, not more than about 1.0 Si, not more than about 1.5 % Mn, not more than about 0.06% P, not more than about 0.03% S, about 11% to about 23% Cr, not more than about 2.0% Ni, about 0.5% to about 3.0% Mo, not more than about 1.0% Al, not more than about 0.04% N, at least one of not more than about 0.8% Nb and not more than about 1.0% Ti, and the balance being Fe and unavoidable impurities, satisfying the relationship: 18&lE;Nb/(C&plus;N)&plus;2Ti/(C&plus;N)&lE;60, wherein C, N, Nb, and. Ti in the relationship represent the C, N, Nb, and Ti contents by mass percent, respectively. A process for making the same is also provided.

Ferritic stainless steel sheet with excellent workability

A finish annealed non-oriented electromagnetic steel sheet includes about 0.01 wt % or less of C, greater than about 1.0 wt % and at most about 3.5 wt % of Si, at least about 0.6 wt % and at most about 3.0 wt % of Al, at least about 0.1 wt % and at most about 2.0 wt % of Mn, at least about 2 ppm and at most about 80 ppm of one or more rare earth metals (REM), a maximum content of Ti and Zr being about 15 ppm and 80 ppm, respectively, wherein oxygen on the surface layer of the steel sheet is 1.0 g/e or less. Since the non-oriented electromagnetic steel sheet has desirable mechanical properties resulting from the increased amounts of Si and Al, a high magnetic flux density can be maintained without sacrificing a punching property as well as very low iron loss can be obtained even after stress relief annealing.

Non-oriented electromagnetic steel sheet having excellent magnetic properties after stress relief annealing and method of manufacturing the same

A finish annealed non-oriented electromagnetic steel sheet includes about 0.01 wt % or less of C, greater than about 1.0 wt % and at most about 3.5 wt % of Si, at least about 0.6 wt % and at most about 3.0 wt % of Al, at least about 0.1 wt % and at most about 2.0 wt % of Mn, at least about 2 ppm and at most about 80 ppm of one or more rare earth metals (REM), a maximum content of Ti and Zr being about 15 ppm and 80 ppm, respectively, wherein oxygen on the surface layer of the steel sheet is 1.0 g/m,or less. Since the non-oriented electromagnetic steel sheet has desirable mechanical properties resulting from the increased amounts of Si and Al, a high magnetic flux density can be maintained without sacrificing a punching property as well as very low iron loss can be obtained even after stress relief annealing.

Non-oriented electromagnetic steel sheet having excellent magnetic properties after stress relief annealing

Method for producing a grain oriented silicon steel sheet comprises heating a silicon steel slab containing about:

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Chiba, Japan

Yoshihiro Ozaki