Aisin Seiki Kabushiki Kaisha

Ryuichi Uchino

Takefumi Isogai

Tadashi Higuchi

Takaaki Nakano

Yoshio Kono

Shigenobu Tara

Masahiko Sato

A method for the heat treatment of steel, comprising carburization hardening said steel, to form carburized steel, followed by a second hardening, reduces the grain size of steel while precipitating carbonitrides inside the grains of steel, thereby increasing the strength of the heat-treated steel. The carburization hardening comprises heating the steel to a first austenitic temperature range in an atmosphere comprising a carburizing gas and optionally ammonia, cooling the steel to a martensitic temperature range, and quenching the steel, and the second hardening comprises heating the carburized steel to a second austenitic temperature range in an atmosphere comprising a carburizing gas and ammonia, and quenching the steel.

Method for heat treatment of steel

A friction plate in the shape of a disc is used in a clutch device to transfer a rotational torque from a driving member to a driven member and has frictional thin films on its side surface. These films are formed by spraying particulate materials on the side surfaces of the friction plate. According to the present invention the thin films are compressed by a compression roller arranged on the way of a path for feeding the metal strip having the thin film on its side surfaces.

Method of manufacturing friction plates

Growing community of inventors

Aichi-ken, Japan

Ryuichi Uchino