Kawasaki Steel Corporation

Osaka Gas Company Limited

Kasasaki Steel Corporation

Tatsuo Kawasaki

Kazuhide Ishii

Hiroshi Ohtsubo

Isao Takada

Akio Nakashiba

Shoji Dohi

Souhei Miyazaki

Noriyuki Kuriyama

Eiko Yasuhara

Kanji I

Martensitic stainless steels that enable the fabrication of high-strength seamless steel pipe suited for use in oil-well pipe and pipeline tubing by means of a Mannesmann plug mill or Mannesmann mandrel mill process, without the formation of defects during production. The heat workability of these steels, which contain no more than 0.30% by weight of carbon and from 11 to 14% by weight of chromium, and have a ferrite content of at least 40% at 1200.degree. C., has been vastly improved by holding the phosphorus and sulfur levels therein to no more than 0.020% and 0.003% by weight, respectively.

Martensitic stainless steels for seamless steel pipe

A far-infrared emitter of high corrosion resistance is prepared by an oxidizing heat treatment of a body made from a stainless steel of 20-35% by weight of chromium, 0.5-5.0% by weight of molybdenum, up to 3.0% by weight of manganese and up to 3.0% by weight of silicon at 900.degree.-1200.degree. C. to form an oxidized surface film having a thickness of at least 0.2 mg/cm.sup.2. Further, a far-infrared emitter of a high emissivity approximating a black body is prepared by subjecting a body made from a stainless steel of 10-35% by weight of chromium, 1.0-4.0% by weight of silicon and up to 3.0% by weight of manganese to a blasting treatment to roughen the surface followed by an oxidizing heat treatment at 900.degree.-1200.degree. C. to form an oxide film on the surface in the form of protrusions having a length of at least 5 .mu.m.

Far-infrared emitter of high emissivity and corrosion resistance and

A far-infrared emitter of high corrosion resistance is prepared by an oxidizing heat treatment of a body made from a stainless steel of 20-35% by weight of chromium, 0.5-5.0% by weight of molybdenum, up to 3.0% by weight of manganese and up to 3.0% by weight of silicon at 900.degree.-1200 .degree. C. to form an oxidized surface film having a thickness of at least 0.2 mg/cm.sup.2. Further, a far-infrared emitter of a high emissivity approximating a black body is prepared by subjecting a body made from a stainless steel of 10-35% by weight of chromium, 1.0-4.0% by weight of silicon and up to 3.0% by weight of manganese to a blasting treatment to roughen the surface followed by an oxidizing heat treatment at 900.degree.-1200 .degree. C. to form an oxide film on the surface in the form of protrusions having a length of at least 5 .mu.m.

Ear-infrared emitter of high emissivity and corrosion resistance and

An oxidation-resistant Fe-Cr-Al steel, having superior workability, oxidation resistance at high temperature and corrosion resistance, has a composition which contains: up to but not more than about 0.05 wt % of C; about 0.1 to about 1.0 wt % of Si; up to but not more than about 1.0 wt % of Mn; from about 3.0 to 7.5 wt % of Cr; from about 4.5 to 6.5 wt % of Al; up to but not more than about 0.05 wt % of N; one or more elements selected from about the group consisting of 1), from about 0.01 wt % to 0.3 wt % of Zr, 2), from 0.01 wt % to 0.3 wt % of Ti, and 3), from about 0.001 wt % to 0.2 wt %, expressed as a total, of Y, La, Ce, Pr, Nd and Hf; and the balance sustantially Fe and incidental inclusions.

Oxidation resistant Fe-Cr-Al steel

A high oxidotion resistance Fe-Cr-Al alloy stainless steel foil suitable for forming catalytic converters, specifically for forming automotive catalytic converters. The alloy includes:

Fe-Cr-Al stainless steel having high oxidation resistance and spalling

A cold-rolled and annealed stainless steel strip is completely descaled in a short process period by electrolizing the strip with an aqueous solution containing ranges of

Process for descaling cold-rolled and annealed stainless steel strip

A duplex stainless steel seamless pipe can be inexpensively produced in high productivity and yield without causing cracks during the working steps in the plug mill process by a proper combination of the composition of the steel and the working conditions of a billet and a hollow piece for the production of the pipe.

Duplex stainless steel seamless pipe and a method for producing the same

A method of manufacturing bimetallic tubes is disclosed. In this method, after an inner tube is inserted into an outer tube, the resulting tube assembly is heated, while pressurizing the inside of the inner tube with a gas, in the presence or absence of a solder material. When using no solder material, the materials of the inner and outer tubes are so selected that a thermal expansion coefficient of the inner tube is smaller than that of the outer tube.

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Chiba, Japan

Tatsuo Kawasaki