Hitachi, Ltd.

Ryo Ishibashi

Yasuhisa Aono

Haruo Akahoshi

Shinya Imano

Hisanori Okamura

Masahisa Inagaki

Kazutaka Okamoto

Kenya Ohashi

Seunghwan Park

Masayuki Doi

Naoya Okizaki

Hideo Soneda

Masami Taguchi

Katsuhito Takahashi

Yoshikazu Todaka

Masakuni Fujikura

Minoru Umemoto

Tomomi Nakamura

Hidehiko Sumitomo

Hiroaki Azuma

Hiroki Masumoto

Nozomu Adachi

Disclosed is a zirconium alloy material having high corrosion resistance regardless of thermal history during its manufacturing process. The zirconium alloy material is obtained by providing a zirconium alloy containing on the mass basis: 0.001% to 1.9% of Sn, 0.01% to 0.3% of Fe, 0.01% to 0.3% of Cr, 0.001% to 0.3% of Ni, 0.001% to 3.0% of Nb, 0.027% or less of C, 0.025% or less of N, 4.5% or less of Hf and 0.16% or less of O with the remainder being inevitable impurities and zirconium, being formed of a bulk alloy and a surface layer, in which the surface layer has a plastic strain of 3 or more or a Vickers hardness of 260 HV or more and an arithmetic mean surface roughness Ra of 0.2 &#x3bc;m or less.

Zirconium alloy material

Provided is high corrosion resistant equipment for a plant having the lining structure which exhibits high reliability against breaking of a joining portion over a long use period. The high corrosion resistant equipment for a plant includes a lining plate and a support portion which are made of a high corrosion resistance material and a structural material portion made of a steel material or the like. The lining plate and the support portion include a joining portion to which friction stirring is applied. The support portion is assembled into or fastened to the structural material portion by means of the geometrical structure with a gap interposed between the support portion and the structural material portion. Due to such a constitution, high corrosion resistant equipment for a plant having the lining which exhibits high reliability can be acquired.

High corrosion resistant equipment for a plant

A high-strength and high-toughness ferritic steel having a tensile strength of not less than 1,000 MPA and a Charpy impact value of not less than 1 MJ/m is provided. A ferritic steel comprising, by weight, not more than 1% Si, not more than 1.25% Mn, 8 to 30% Cr, not more than 0.2% C, not more than 0.2% N, not more than 0.4% O, a total amount of not more than 12% of at least one compound-forming element selected from the group of Ti, Zr, Hf, V and Nb in amounts of not more than 3% Ti, not more than 6% Zr, not more than 10% Hf, not more than 1.0% V and not more than 2.0% Nb, also containing where necessary not more than 0.3% Mo, not more than 4% W and not more than 1.6% Ni, and the balance consisting of Fe and unavoidable impurities, and having an average crystal grain size of not more than 1 &mgr;m, can be obtained by a method comprising encapsulating a steel powder produced by mechanical alloying, and subjecting the encapsulated steel powder to plastic deformation.

High-toughness and high-strength ferritic steel and method of producing the same

A corrosion resistant, high strength austenitic stainless steel consisting of 1.0% or less of Si, 2.0% or less of Mn, 0.5% or less of O, 7 to 30% of Ni, 14 to 26% of Cr, 0.3% or less of combination of C and N, at least one element selected from the group consisting of 1.0% or less of Ti, 2.0% or less of Zr and 2.0% or less of Nb, and the balance consisting of Fe and unavoidable impurities, the percentage being given in weight basis; said steel containing carbonitride with a grain size of several to 100 nm dispersed therein; said steel having an average crystal grain size of 1 &mgr;m or less; and said steel containing 90% by volume or more of austenite phase; is excellent in strength and corrosion resistance.

Corrosion resistant, high strength alloy and a method for manufacturing the same

Structural components obtained by a process for welding iron-base materials, where the iron-base material is iron-base fine grained materials free from any amorphous phase, which comprises welding two kinds of fine grained materials of chemical and crystallographically same or different kinds from one another, whose average grain sizes d are in a range of 10 nm<d&lE;5&times;10 nm, etc., by friction stir welding can maintain distinguished properties of fine grained materials, such as strength and corrosion resistance.

Welding processes for iron-base ultra fine grained materials and structural components manufactured by the processes

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Hitachi, Japan

Ryo Ishibashi