Other

Kabushiki Kaisha Kobe Seiko Sho

Shinko Kobelco Tool Co., Ltd.

Masahiro Machida

Yusuke Tanaka

Yasuyuki Yamada

Taiitsu Aoki

Kazuaki Tanaka

Yasushi Onishi

Yuji Komori

Kenzo Takashina

Masaru Ishii

Takeo Komine

Hideto Kurata

Yukio Aoki

A heat treatment method of steel is capable of enhancing wear resistance, mechanical properties and dimensional stability of the steel due to the reduction of the retained austenite amount to substantially zero. In the method, an article of the steel is subjected to a quenching and then subzero treatment including cooling it at a cooling rate of 1 to 10&deg; C./min. to a cooling temperature and holding the cooling temperature for a predetermined period of time.

Heat treatment method of steel

The present invention has as its objective the provision of a cemented carbide (for a drill) which has excellent breakage resistance and which displays good adhesion when coated with a hard-carbon coating; as well as the provision of a drill for forming holes in printed circuit boards which is made using said cemented carbide. It is a WC-iron group metal cemented carbide having as its main component WC having an average grain size of 0.7 .mu.m or less; containing 0.1 to 3.0 weight percent of one or more types selected from the group consisting of V, Cr, Ta and Mo; whose surface layer consists of substantially only WC or only WC grains and components other than binder phase comprising iron group metals; wherein the average grain size of the WC in the surface layer is larger than the average grain size of the WC in the interior; and wherein the Young's Modulus at the interior is 600 MPa or higher.

Cemented carbide for a drill, and for a drill forming holes in printed

A coated member comprising a substrate, an intermediate layer on the substrate consisting essentially of aluminum and titanium, and a hard coating of (Al, Ti) (N, C) on the intermediate layer. The coated member has an improved wear resistance because the intermediate layer raises the level of adhesion between the substrate and the hard coating.

Coated member having excellent hardness and, adhesive properties

Growing community of inventors

Akashi, Japan

Masahiro Machida