Nippon Steel Corporation

Nippon Steel Chemical & Material Co., Ltd.

Nippon Steel & Sumikin Materials Co., Ltd.

Nippon Steel Materials Co., Ltd.

Nippon Steel & Sumkin Materials Co., Ltd.

Toru Inaguma

Hiroaki Sakamoto

Naoki Fujimoto

Hiroto Unno

Naoya Sawaki

Masahiro Fukuda

Tomohiro Uno

Kazuo Sugino

Takayuki Kobayashi

Koichi Nose

Tatsuo Fujimoto

Yasuhiro Nakata

Shinichi Terashima

Shuji Nagasaki

Toshio Mukai

Mitsuhiko Yazaki

The present invention has as its object to provide thickness 60 &#x3bc;m or less ultra-thin stainless steel foil which secures high thickness precision and simultaneously secures plastic deformability and good elongation at break, that is, secures good press-formability (deep drawability). The present invention solves this problem by ultra-thin stainless steel foil which has three or more crystal grains in a thickness direction, has a recrystallization rate of 90% to 100%, and has a nitrogen concentration of a surface layer of 1.0 mass % or less. For this reason, there is provided a method of production of stainless steel foil comprising rolling stainless steel sheet, then performing final annealing and making a thickness 5 &#x3bc;m to 60 &#x3bc;m, wherein a rolling reduction ratio at rolling right before final annealing is 30% or more, a temperature of final annealing after rolling is 950&#xb0; C. to 1050&#xb0; C. in the case of austenitic stainless steel and 850&#xb0; C. to 950&#xb0; C. in the case of ferritic stainless steel, and a nitrogen content in atmospheric gas in final annealing is 0.1 vol % or less, whereby ultra-thin stainless steel foil can be produced.

Stainless steel foil and method of production of same

The present invention provides a ferritic stainless steel foil high in stretch-expand formability and further small in anisotropy of deformation with respect to stretch-expand forming even with ultrathin steel foil with a thickness of 60 &#x3bc;m or less. The ferritic stainless steel foil has a thickness of 5 &#x3bc;m to 60 &#x3bc;m, wherein a recrystallization rate of the stainless steel foil is 90% to 100%, and in an orientation distribution function obtained by analysis of a crystalline texture of the stainless steel foil, when a Euler angle &#x3c6;2 is 45&#xb0;&#xb1;10&#xb0;, at a plane expressed by a Euler angle &#x3a6; of 53.4&#xb0;&#xb1;10&#xb0;, a maximum peak strength ratio in peak strength ratios shown by orientations corresponding to a Euler angle &#x3c6;1 is 25 or less, where the Euler angle &#x3c6;1 is 0 to 90&#xb0;. The ferritic stainless steel foil may be laminated with a resin film and is useful for producing a battery case.

Ferritic stainless steel foil

The present invention provide a ferritic stainless steel foil having a high thickness precision even with a thickness 60 &#x3bc;m or less ultrathin stainless steel foil and simultaneously having a plastic deformation ability and good elongation at break, that is, having a good press-formability (deep drawing ability). The present invention is a stainless steel foil having a thickness of 5 &#x3bc;m to 60 &#x3bc;m, wherein a recrystallization ratio of said stainless steel foil is 90% to 100%, a surface layer of said stainless steel foil has a nitrogen concentration of 1.0 mass % or less, three or more crystal grains are contained in the thickness direction of said stainless steel foil, an average crystal grain diameter 'd' of said crystal grains is 1 &#x3bc;m to 10 &#x3bc;m, and, when said thickness is 't' (&#x3bc;m), an area ratio of crystal grains having a crystal grain diameter of t/3 (&#x3bc;m) or more is 20% or less.

Stainless steel foil

Provided is an austenitic stainless steel foil that demonstrates a high degree of stretch formability and little deformation anisotropy with respect to stretch forming despite having a sheet thickness of 60 &#x3bc;m or less. The austenitic stainless steel foil of the present invention has a sheet thickness of 5 &#x3bc;m to 60 &#x3bc;m, a recrystallization rate of 90% to 100%, and a texture in which the total of the area ratio of a crystal orientation in which the difference in orientation from the {112}&#x3c;111&#x3e; orientation is within 10&#xb0;, the area ratio of a crystal orientation in which the difference in orientation from the {110}&#x3c;112&#x3e; orientation is within 10&#xb0;, and the area ratio of a crystal orientation in which the difference in orientation from the {110}&#x3c;001&#x3e; orientation is within 10&#xb0;, in a measuring field thereof, is 20% or less.

Austenitic stainless steel foil

The present invention provides a high Al-content steel sheet having an excellent workability and a method of production of the same at a low cost by mass production, a high Al-content metal foil and a method of production of the same, and a metal substrate using a high Al-content metal foil, that is, a high Al-content steel sheet having an Al content of 6.5 mass % to 10 mass %, the high Al-content steel sheet characterized by having one or both of a {222} plane integration of an &#x3b1;-Fe crystal with respect to the surface of the steel sheet of 60% to 95% or a {200} plane integration of 0.01% to 15% and a method of production of the same, a high Al-content metal foil and a method of production of the same, and a metal substrate using a high Al-content metal foil.

High Al-content steel sheet excellent in workability and method of production of same

In a method of diagnosing the fatigue life of structural steelwork according to the present invention, a Barkhausen noise measurement is performed under the condition of 5 .mu.m.ltoreq.d.ltoreq.1 mm where d is the detection depth of Barkhausen noise, by using a magnetic head constituted by an air-core coil detection head and a magnetic excitation head obtained by winding a copper wire such as an enameled wire on a U-shaped core made of a soft magnetic material such as a silicon steel sheet or an amorphous magnetic material. The degree of fatigue damage of a target measurement portion is diagnosed using the root-mean-square (RMS) voltage or voltage amplitude value of the Barkhausen noise. According to this method, the degree of fatigue and degradation by stress and strain in the structural steelwork can be accurately diagnosed prior to development of cracking without any limitation on diagnostic locations. A member of steelwork having a life diagnostic function is obtained by mounting the above magnetic head on a brace- or wall-like vibration-damping device made of very low-yield steel. According to this member of steelwork, the wall or covering material of a bridge or the like need not be removed even in practicing a fatigue life diagnosis. The degree of fatigue degradation in structural steelwork can be easily and accurately diagnosed prior to development of cracking even in a location where an operator cannot access due to the structural limitation.

Method of diagnosing fatigue life of structural steelwork and a member

Rail axial-force measuring method and an axial-force measurable rail

Stress sensor fabricated from a material having precipitated granular

An arrangement of the magnetic detection and excitation head has an excitation head with a U-shaped excitation core of soft magnetic material forming two legs, each having an end plane facing a surface of a measured object, and an excitation coil wound on the core excitable by a low frequency current; and a detection head with a rod-shaped detection core of non-magnetic or soft magnetic material and a detection coil wound thereon. An end plane of the detection core which is to be close to the surface of the object, and the end planes of the two legs of the excitation core are arranged such that the end plane of the detection core is between the end planes of the two legs and all the end planes are substantially on a common flat plane. Also, a position of the detection head relative to the excitation head is selected such that when an AC current of a predetermined frequency is supplied to the excitation coil, a selected one of a total induced voltage signal, which includes a voltage signal having substantially the same frequency as that of the supplied AC current and a Barkhausen signal induced into the detection coil, and the Barkhausen signal alone is detected.

Arrangement of excitation and detection heads for detecting the magnetic

Rare earth magnets comprising 12 to 20 at % R (where R denotes rare earth elements including at least one selected from neodymium and praseodymium) and 2 to 10 at % boron, with the remainder being TM (where TM=Fe.sub.1-x Co.sub.x (0.ltoreq.x.ltoreq.0.4)) and unavoidable impurities, wherein 50 to 100 vol % of the magnet is formed of recrystallization grains of R.sub.2 Fe.sub.14 B intermetallic compound having a tetragonal crystal structure with an average grain size of 1 to 100 .mu.m and an induced anisotropy P of 0.1 or more (where P=(Br(.parallel.)-Br(.perp.))/(Br(.parallel.)+Br(.perp.)), Br(.parallel.) being residual magnetic flux density along the easy magnetization axis and Br(.perp.) being residual magnetic flux density perpendicular to the easy magnetization axis), and the method of producing the rare earth magnets.

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Tokyo, Japan

Toru Inaguma