Free-cutting tool steel

US6761853B2 · kind B2 · utility

Assignees

• Kiyohito Ishida · JP
• Katsunari Oikawa · JP
• Dokuritsu Gyousei Houjin Sangyo Gijutsu Sougo Kenkyusho · JP
• Daido Tokushuko Kabushiki Kaisha · JP

Inventors

• Kiyohito Ishida · Sendai, JP
• Katsunari Oikawa · Murata, JP
• Toshimitsu Fujii · Nagoya, JP
• Yukinori Matsuda · Nagoya, JP
• Kozo Ozaki · Võru, EE
• Seiji Kurata · Nagoya, JP
• Takayuki Shimizu · Tokyo, JP

Key dates

• Filing date: Feb 28, 2002
• Grant date: Jul 13, 2004
• Expiry date: Feb 28, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C22C38/52
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A free-cutting tool steel is provided containing Fe and C in an amount of 0.1 to 2.5 wt %, Ti and or Zr where WTi+0.52WZr constitutes 0.03 to 3.5 wt %, and WTi represents Ti content and WZr represents Zr content, at least any one of S, Se and Te where WS+0.4WSe+0.25WTe constitutes 0.01 to 1.0 wt %, and (WTi+0.52WZr)/(WS+0.4WSe+0.25WTe) constitutes 1 to 4, and WS represents S content, WSe represents Se content and WTe represents Te content; and dispersed therein a texture thereof from 0.1 to 10% in terms of area ratio in a section of a machinability improving compound phase of a metallic element component of Ti and/or Zr as major components, and a binding component for the metallic element component containing C and any one of S, Se and Te.