Daido Steel Co., Ltd.

Honda Motor Co., Ltd.

Ayumi Yamazaki

Takahiro Miyazaki

Shinichiro Kato

Hideki Matsuda

Makoto Haritani

Hiroki Terada

Yuuki Tanaka

Ryuta Motani

Yushi Fujinaga

Yusuke Yoshimi

Hiroki Masuda

Ryosuke Ohashi

Kentaro Shimada

The present invention provides a steel material which is excellent in both of the strength (particularly, fatigue strength) and the manufacturability (particularly, bending straightening properties), and thus can be used as an automobile component such as a crankshaft by being formed into a product shape, being subjected to a high strength treatment such as a nitrocarburizing treatment, and then being subjected to the bending straightening.

Steel material, crankshaft, and automobile component

The present invention relates to a part obtained from an age hardening type bainitic microalloyed steel, a process for producing the part, and the age hardening type bainitic microalloyed steel. In particular, the present invention relates to a part which has been controlled so as to have higher values of strength than conventional parts, a process for producing the part, and the age hardening type bainitic microalloyed steel.

Part obtained from age hardening type bainitic microalloyed steel, process for producing part, and age hardening type bainitic microalloyed steel

Provided is a method of manufacturing a nitrocarburized crankshaft which is obtained by subjecting a bainitic microalloyed steel to a forging and a machining, and further subjecting the bainitic microalloyed steel to at least a strain releasing heat treatment and a subsequent nitrocarburizing treatment, the bainitic microalloyed steel containing, as essentially added elements, in terms of mass %: 0.10% to 0.40% of C; 0.10% to 1.0% of Si; 1.0% to 2.0% of Mn; 0.05% to 0.40% of Mo; and 0.05% to 0.40% of V, and the bainitic microalloyed steel optionally further containing, as arbitrarily added elements, in terms of mass %: 0.01% to 0.1% of S; 0.005% to 0.2% of Ti; 0.001% to 0.03% of Al; 0.50% or less of Cr; 0.5% or less of Cu; and 0.5% or less of Ni, with the balance being Fe and unavoidable impurities.

Nitrocarburized crankshaft and method of manufacturing the same

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Aichi, Japan

Ayumi Yamazaki