Abstract: A near field optical recording medium having a header area in which at least an addressing signal or a timing signal is recorded by means of a concave/convex pattern with laser light using a flying optical head. When a concave/convex portion of the concave/convex pattern is to be detected, either an effect due to a change in returning light caused by distance wherein the reflectance is changed or an effect due to a change in returning light caused by a diffraction effect is sufficiently larger, or a combination of such effects (changes by distance effect and changes by diffraction effect) are not weakened by each other, so that header information recorded by the concave/convex pattern can correctly be reproduced even in a super-high density recording medium using near field light.

Abstract: An optical recording medium able to reproduce address information during seeking in which an optical head moves between tracks, to increase seek speed, to improve recording/reproduction speed and to obtain a good header reproducing signal is achieved by that the concave portions or convex portions constituting a reproducing signal in seeking reproduced even during seek and/or constituting a timing signal for writing a header signal are connected to each other in a direction orthogonal to the tracks, when these concave portions and/or convex portions are placed in positions equivalent to each other in the adjacent tracks.

Abstract: A near field optical recording medium having a header area in which at least an addressing signal or a timing signal is recorded by means of a concave/convex pattern with laser light using a flying optical head. When a concave/convex portion of the concave/convex pattern is to be detected, either an effect due to a change in returning light caused by distance wherein the reflectance is changed or an effect due to a change in returning light caused by a diffraction effect is sufficiently larger, or a combination of such effects (changes by distance effect and changes by diffraction effect) are not weakened by each other, so that header information recorded by the concave/convex pattern can correctly be reproduced even in a super-high density recording medium using near field light.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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:C: less than or equal to 0.02 Wt %;Si: less than or equal to 1.0 Wt %;Cr: in a range greater than or equal to 14 Wt % to less than or equal to 27 Wt %;Al: in a range greater than or equal to 3.5 Wt % to less than or equal to 6.5 Wt %;La: in a range greater than 0.05 Wt % and less than or equal to 0.20 Wt %;Ce: less than or equal to 0.01 Wt % and the remainder being composed of Fe and inevitable impurities, the foil having a thickness less than or equal to 80 .mu.m.

Abstract: 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 ofx (g/l)=50 to 270 (1)y (g/l)=(-0.01 x+3.8) to (-0.05x+21) (2),where x is concentration of nitric anid in g/l and y is concentration of chlorine in g/l.

Abstract: 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.

Abstract: 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.