Nisshin Steel Co., Ltd.

Sanoh Kogyo Kabushiki Kaisha

Yoshihiro Uematsu

Katsuhisa Miyakusu

Naoto Hiramatsu

Takashi Igawa

Kazuo Hoshino

Shigeaki Maruhashi

Hiroshi Fujimoto

Takehiko Fujimura

Masayuki Kinugasa

Toshihiko Takemoto

Sadayuki Nakamura

Manabu Oku

Yukio Oda

Akira Sakakura

Isami Shimizu

Naoto Okubo

Koichi Satake

Nobukazu Fujimoto

Yukito Nomura

Juichi Ozawa

Stainless steel excellent in fused-salt corrosion resistance and method

Ferritic stainless steel excellent in high temperature oxidation

A multifold pipe made by multiple rolling up and turning of a copper coated steel sheet into a multifold pipe, characterized in that said steel sheet is a cold rolled sheet of a super soft austenitic stainless steel comprising by weight: up to 0.05% of C, up to 1.0% of Si, up to 5.0% of Mn, from 9.0% to 15.0% of Ni, from 15.0% to 20.0% of Cr, up to 0.04% of N, up to 5.0% of Cu, the balance being Fe and unavoidable impurities, wherein the alloying elements are further adjusted so that both the two relations (1) and (2) noted below are satisfied:

Stainless steel multifold pipe

A ferric stainless steel consists by weight of less than 0.03% carbon, less than 1% silicon, less than 1% manganese, less than 0.04% phosphorus, less than 0.03% sulphur, from 15% to 25% chromium, less than 0.03% nitrogen, from 3% to 6% aluminum, from 0.1% to 4% molybdenum. A small amount of rare-earth elements and yttrium of from 0.01% to 0.15% are added in the steel.

High-aluminum-containing ferritic stainless steel having improved

A high strength chromium containing steel sheet having a tensile strength of at least 40 kgf/mm.sup.2, and excellent in corrosion resistance and workability, comprising, by weight, C:up to 0.030%, Si:up to 2.30%, Mn:up to 3.0%, P:more than 0.0005% and not more than 0.150%, S:up to 0.010%, Ni:up to 2.0%, Cu:more than 0% and not more than 2.0%, Cr:not less than 5.0% and less than 10.0%, N:up to 0.030%, V:not less than 0.01% and not more than 0.10%, and optionally at least one of 0.01 to 0.30% of Ti, 0.01 to 0.30% of Nb, 0.01 to 0.30% of Zr, 0.01 to 0.20% of Al and 0.0002 to 0.0200% of B, the amounts of Si, Mn, P, Ni and Cu being adjusted so that the relation:Si+Mn+10P+Ni+Cu&gt;1.0% may be satisfied, the balance being iron and unavoidable impurities.

Chromium containing high strength steel sheet excellent in corrosion

A heat resisting ferritic stainless steel which comprises, by weight, up to 0.03% of C, from 0.1 to 0.8% of Si, from 0.6 to 2.0% of Mn, up to 0.006% of S, up to 4% of Ni, from 17.0 to 25.0% of Cr, from 0.2 to 0.8% of Nb, from 1.0 to 4.5% of Mo, from 0.1 to 2.5% of Cu, and up to 0.03% of N, and optionally one or more of appropriate amounts of Al, Ti, V, Zr, W, B and REM, the balance being Fe and unavoidable impurities, wherein the alloying elements are further adjusted so that the ratio of Mn%/S% is not less than 200, [Nb] defined by the equation: [Nb]=Nb%-8 (C%+N%) is not less than 0.2, and (Ni%+Cu%) is not more than 4. The stainless steel according to the invention is suitable for use in constructing an exhaust gas path-way of an automobile, particularly, a path-way from an engine to a converter, which is exposed to high temperatures, and which requires an improved low temperature toughness and a high resistance to weld cracking due to high temperatures.

Heat resisting ferritic stainless steel excellent in low temperature

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.

Process for producing high strength endless steel belt having a duplex

A chromium containing steel sheet excellent in corrosion resistance and workability, comprising, by weight, C:up to 0.030%, Si:up to 0.5%, Mn:up to 0.5%, P:up to 0.040%, S:up to 0.010%, Ni:up to 0.3%, Cu:up to 0.3%, Cr: not less than 5.0% and less than 11.0%, N:up to 0.030%, V:not less than 0.01% and not more than 0.10%, and optionally at least one of 0.01 to 0.30% of Ti, 0.01 to 0.30% of Nb, 0.01 to 0.30% of Zr, 0.01 to 0.20% of Al and 0.0002 to 0.0200% of B, the amounts of Si, Mn, P, Ni and Cu being adjusted so that the relation:Si+Mn+10P+Ni+Cu.ltoreq.1.0% may be satisfied, the balance being iron and unavoidable impurities.

Chromium containing steel sheet excellent in corrosion resistance and

A high strength steel strip excellent in shape having 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, causing the strip to continuously pass through a continuous heat treatment furnace under tension where the strip is heated to temperatures within the range from (the As point of the steel+30.degree. C.) to the 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 cooling the heated strip to ambient temperature, wherein the As point of the steel is a temperature of the steel of which temperature is being raised at which the transformation of martensite to austenite begins and the Af point of the steel is a temperature of the steel of which temperature is being raised at which the transformation of martensite to austenite is finished.

Process for producing high strength stainless steel strip excellent in

A heat-resistant austenitic stainless steel is disclosed. This steel essentially consists of: not more than 0.06% C, 1-4% Si, 0.5-4% mn, not more than 0.035% P, not more than 0.005% S, 10-17% Ni, 14-20% Cr, 1-4% Mo, 0.01-0.5% Al, not more than 0.035% N, and balance essentially Fe, and may further contain small amounts of any of Cu, REM and B and the composition thereof is adjusted so that a limited amount of .delta.-ferrite appears in solidification. The steel has excellent hot salt corrosion resistance, weldability, salt errosion resistance of the weld and hot-workability.

Heat-resistant austenitic stainless steel

A process for the production of an electrical steel sheet having the ideal (100) [001] cube texture of iron of iron alloy, comprising cold rolling a sheet of a single crystal or large grained crystals of iron or iron alloy, in which said single crystal is or a majority of said large grained crystals are oriented so that the pole of the {114} plane may form an angle not greater than 15.degree. with the normal direction of the plane of the sheet, and the &lt;401&gt; direction may form an angle of not greater than 15.degree. with a single direction in the plane of the sheet, in said single direction at a rolling reduction of at least 40%, and annealing the rolled sheet to form a primary recrystallization texture of fine grains of an average grain size of not larger than 5 mm under conditions preventing the occurrence of secondary recrystallization.

Process for producing electrical steel sheet

A corrosion resistant alloy comprising in % by weight up to 0.05% of C, 10.00 to 18.00% of Cr, up to 1.00% of Si, up to 1.00% of Mn, more than 0.040% but not more than 0.150% of P, up to 0.050% of S, up to 0.60% of Ni and 0.005 to 0.50% of sol.Al, the balance being Fe and unavoidable impurities. The alloy has an enhanced pickling performance of the hot rolled material and an improved workability of the cold rolled material.

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Kudamatsu, Japan

Yoshihiro Uematsu