Hitachi, Ltd.

Fumio Hataya

Yutaka Fukui

Tetsuo Kashimura

Fumito Nakajima

Ryoichi Sasaki

Ryo Hiraga

Shimpei Matsuda

Tsutomu Onuma

Munehiko Tonami

Noriaki Mase

Yoshimitsu Tobita

Mitsuhiro Watanabe

A welded structural member adapted to be subjected to a flowing fluid and comprising a base member consisting mainly of iron and a coating layer formed by a build-up welding on the surface of the base member, the coating layer having a higher erosion resistance than the base member. The coating layer contains 0.03 to 0.4 wt % of C, 0.1 to 1 wt % of Si, 0.5 to 20 wt % of Mn, 1 to 5.5 wt %, of Ni, 1 to 12 wt % of Co, 8 to 23 wt % of Cr and the balance Fe. The structure of the coating layer is mainly unstable austenite.

Welded structural member having high erosion resistance

A sliding mechanism comprising two members maintained in sliding contact with each other, wherein one of the members (which may be a pin) is formed of an alloy consisting essentially of, by weight, less than 0.3% carbon, 7-40% nickel, 15-28% chromium, 2-8% silicon, 3-12% manganese and the balance essentially iron, and the other member (which may be a roller) is formed of an alloy consisting essentially of, by weight, less than 0.5% carbon, 13-22% chromium, less than 2% silicon, less than 2% manganese, 3-10% molybdenum, 10% of at least one of titanium and aluminum and the balance essentially nickel, the two members having a difference in Vickers hardness of below 200 at their contact surfaces. The sliding mechanism has particualr utility as means for guiding a control rod of a nuclear reactor by means of pins and rollers.

Sliding mechanism

The present alloys of iron-nickel-chromium-molybdenum system are alloys having high strength and ductility, comprising 0.03-0.2% by weight of carbon, not more than 2% by weight of silicon, not more than 2% by weight of manganese, 42-70% by weight of nickel, 15-35% by weight of chromium, 4.5-15% by weight of molybdenum, 0.05-1.0% by weight of at least one of Ti and Nb as additive elements, and 7.5-35% by weight of iron, the balance being incidental impurities, or further contain 0.1-10% by weight of at least one of tungsten and cobalt as reinforcing elements.

Highly ductile alloys of iron-nickel-chromium-molybdenum system for gas

A cobalt base alloy consisting essentially of, in weight percent, about 0.1% to about 0.5% carbon, about 0.3% to about 2.0% silicon, about 0.3% to about 2.0% manganese, about 5.0% to about 15.0% nickel, about 26.0% to about 35.0% chromium, about 3.0% to about 10.0% tungsten, about 0.003% to about 0.1% boron, about 0.01% to about 1.0% titanium, about 0.01% to about 1.0% niobium and optionally about 0.05% to about 1.0% mischmetal and the balance being essentially cobalt together with impurities and incidental elements normally associated with a cobalt base alloy, which has high strength and high ductility even at high temperatures and is especially suitable as a material to be used at high temperatures under high thermal stress, such as a material for a nozzle of a gas turbine engine.

Cobalt base alloy

A catalyst layer is formed on the metallic surface of a structure constructing a reactor by diffusing a developable metal into the structure by the pack cementation method and developing the diffused metal. The catalyst layer is metallurgically combined with the structure, so that it has excellent mechanical strength and heat conductivity. Thus, by using the structure having the catalyst layer as a heat exchanger type methanation reactor it is possible to obtain a methanation reactor enabling an extremely enhanced rate of reaction to be obtained with superior operability and at great savings.

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Hitachi, Japan

Fumio Hataya