Komatsu Corporation

Osaka University

Hensley Industries, Inc.

Shohei Ikurumi

Koji Yamamoto

Takanori Nagata

Yusuke Hiratsuka

Takeshi Fujimatsu

Yoritoshi Minamino

Koji Hagihara

Stanley Ignacio

Toshiyuki Sugimoto

Dan Yumoto

A steel with high hardness and excellent toughness contains, in mass %, 0.40-1.00% C, 0.10-2.00% Si, 0.10-1.00% Mn, 0.030% or less P, 0.030% or less S, 1.10-3.20% Cr, 0.010-0.10% Al, and 0.15-0.50% V, and further contains at least one or two of 2.50% or less Ni and 1.00% or less Mo, with an amount of (C+V) being 0.60% or more in mass %, with the balance consisting of Fe and unavoidable impurities. The steel has a microstructure which is a martensitic structure with finely dispersed Fe-based &#x3b5; carbides, with its prior austenite grain size being 20 &#x3bc;m or less.

Steel with high hardness and excellent toughness

The tooth adapter partly inserted into a cavity formed in a tooth to hold the tooth with respect to a bucket body includes a connection portion including a proximal end, which is an end of the tooth adapter connected to the bucket body, and an insertion portion including a distal end, which is an end of the tooth adapter inserted into the cavity. The insertion portion includes a base, and a high-hardness portion formed in a region including a surface of the insertion portion, the high-hardness portion being higher in hardness than the base.

Tooth adapter and bucket

Growing community of inventors

Tokyo, Japan

Shohei Ikurumi