Hitachi Metals, Ltd.

Kazuhiro Yamamura

Toshihiro Uehara

Takao Ishikawa

Masahiro Tobise

Shigenori Tanaka

Provided is a blade material having high strength. The blade material contains, in % by mass, 0.5 to 0.8% of C, 1.0% or less of Si, 1.0% or less of Mn, 11 to 15% of Cr, and 0.1 to 0.8% of V, the remainder includes Fe and inevitable impurities, and has a thickness of 0.5 mm or less, wherein the structure of the blade material as observed after polishing the surface thereof has ferrites and carbides, the carbides have an average particle diameter of 0.5 &#x3bc;m or less, and a proportion of carbides containing V in the carbides is 50% or less in terms of a proportion in an area of a field of view.

Blade material

There is provided a steel for solid oxide fuel cells which contains more than 0 and not more than 0.05 mass % of C, 0.05 mass % or less of N, 0.01 mass % or less of O, 0.2 mass % or less of Al, 0.15 mass % or less of Si, 0.1 to 1.0 mass % of Mn, 20.0 to 25.0 mass % of Cr, more than 0 mass % and not more than 1.0 mass % of Ni, 0.02 to 0.12 mass % of La, 0.1 to 0.5 mass % of Zr, 0.15 to 0.5 mass % of La+Zr, and Fe and impurities as a remainder. The following relational formula is satisfied, and an Fe and Zr-containing intermetallic compound viewed in a ferrite matrix is 1.1 % or less in terms of a visual field area ratio5(7C+6N)/(7&#x2212;4(7C+6N))&#x2264;Zr&#x2264;41(7C+6N)/(7+66(7C+6N)).

Steel for solid oxide fuel cells and manufacturing method thereof

Disclosed is a hydrogen separation alloy which is adoptable to a product having a large surface area of a side where hydrogen permeates and which has such a metallographic structure as to improve hydrogen permeability and to improve hydrogen-embrittlement resistance. The hydrogen separation alloy used herein is represented by the compositional formula: NbMMwhere Mis at least one element selected from the group consisting of Ti, Zr and Hf; Mis at least one element selected from the group consisting of Ni, Co, Cr, Fe, Cu and Zn; 10&#x2266;&#x3b1;&#x2266;60, 10&#x2266;&#x3b2;&#x2266;50, and &#x3b1;+&#x3b2;&#x2266;80. The alloy contains inevitable impurities. And the alloy includes two phases, i.e., an Nb-Mphase serving as a hydrogen-permeable phase, and a M-Mphase serving as a hydrogen-embrittlement-resistant phase. The hydrogen-permeable phase and the hydrogen-embrittlement-resistant phase have an elongated structure resulting from rolling. The hydrogen-permeable phase occupies 35% to 70% of an arbitrary 10 &#x3bc;m&#xd7;10 &#x3bc;m region in a 50 &#x3bc;m&#xd7;50 &#x3bc;m observation plane of a cross section of the alloy under an electron microscopic observation, the cross section is taken in a direction of thickness reduced by the rolling and in a direction of rolling and flattening.

Hydrogen separation alloy and method for producing same

It is an objective of the invention to provide a method for operating hydrogen separation devices which is capable of efficiently suppressing hydrogen embrittlement in a hydrogen separation alloy membrane and to provide a hydrogen separation device that performs favorably during repeated starting/stopping operations thereof. There is provided a method for operating a hydrogen separation device for separating hydrogen from a mixture hydrogen gas using a membrane separation technique with a hydrogen separation alloy membrane. The method comprises the successive steps of: stopping supply of the mixture hydrogen gas to the hydrogen separation alloy membrane with a temperature of the membrane within a range from 300 to 600&#xb0; C.; supplying an oxidizing gas over a predetermined duration to at least an upstream side of the membrane with a temperature of the membrane within a range from 300 to 600&#xb0; C.; and lowering the temperature of the membrane to below 200&#xb0; C.

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Yasugi, Japan

Kazuhiro Yamamura