Kimura Chuzosho Co., Ltd.

Mitsubishi Materials Corporation

Osaka University

Nippon Sublance Probe Engineering Ltd.

Kimura Foundry Co., Ltd.

Kimura Chuosho Co., Ltd.

Toshitake Kanno

Jun Iwahashi

Hidetoshi Fujii

Mayuki Morinaka

Yasushi Kubota

Hidetaka Hiraoka

Naoshi Yamashita

Kouichi Mabuchi

Yasufumi Yamaguchi

Noriyuki Kakehashi

Noriaki Miwa

Tomohisa Kawaji

Tsuneharu Sugie

Yoya Fukuda

Eiichi Sahara

A method of metal surface hardening treatment inducing transformation, in which transformation is induced in a surface interior of material as hardening treatment object by simple, rapid treatment utilizing a frictional heat under pressure without the occurrence of melt loss, quench crack, soft spot, deformation, etc. to thereby reform the structure of surface interior of material as hardening treatment object into a miniaturized martensitic structure. The method of surface hardening treatment comprised the steps of while rotating nearly cylindrical pressurization tool () at high velocity, pressing the bottom face thereof slightly into the surface of material as hardening treatment object () so as to attain application of given pressure, thereby generating a local frictional hear between the pressurization tool and the material as hardening treatment object; inducing transformation in the material as hardening treatment object at the locality having been exposed to the frictional heat; and when the surface of material as hardening treatment objent positioned in the vicinity of the pressurization tool starts to soften by the frictional heat, moving the pressurization tool.

Transformable metal surface hardening method

A combined roll is provided which offers excellent resistance to thermal shock. In this combined roll, an external ring portion is formed of a cemented carbide, and an internal ring portion is formed of a ductile iron metallurgically bonded to the external ring portion by means of casting. The external ring portion is formed of a cemented carbide containing, as binder phase-defining components, Co: 5-27%, Ni: 2-12% and Cr: 0.3-3% and WC as substantially all of the balance and as a hard phase-defining component. The internal ring portion is formed of a ductile iron composed of C: 3 4.5%, Si: 1.5-4.5%, Mn: 0.1-2% and Mg: 0.02-0.2% and, as the balance, Fe and incidental impurities. The internal ring portion may also contain 0.1-5% of one or more of Mo, Cu, Cr, V, W, Sn and Sb. The internal ring portion contains a cored spheroidal graphite structure dispersed in a mixed phase of either perlite, beinite and martensite phases with a ferrite phase. The cored spheroidal graphite structure has a spheroidal graphite core formed during casting and a periphery deposited around the core during thermal treatment.

Combined roll having excellent resistance to thermal shock

Method of regenerating foundry sand

A method for judging the properties of molten cast iron which consists of connecting three sampling vessels with an apparatus for obtaining a cooling curve of molten cast iron, measuring a cementite eutectic temperature (TEC) of cast iron poured to the first sampling vessel to which a chilling agent is contained, measuring a eutectic freezing temperature change of molten cast iron poured to the second sampling vessel being free of any additive, measuring a graphite eutectic temperature (TEG) of molten cast iron poured to the third sampling vessel, and inspecting a relation between the cementite eutectic temperature (TEC) and the graphite eutectic temperature (TEG) within the range of the eutectic freezing temperature change of molten cast iron.

Method for judging the properties of molten cast iron

Growing community of inventors

Shizuoka-ken, Japan

Toshitake Kanno