Mitsubishi Materials Corporation

Kimura Chuzosho Co., Ltd.

Nippon Sublance Probe Engineering Ltd.

Kimura Foundry Co., Ltd.

Jun Iwahashi

Toshitake Kanno

Mayuki Morinaka

Yasushi Kubota

Hidetaka Hiraoka

Noriaki Miwa

Tsuneharu Sugie

Naoshi Yamashita

Eiichi Sahara

Kouichi Mabuchi

Noriyuki Kakehashi

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

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

Jun Iwahashi