Title:
中空円筒状ワークの熱処理方法
Document Type and Number:
Japanese Patent JP4187334
Kind Code:
B2
Abstract:
A method for heat-treating a hollow cylindrical workpiece (11) includes quench-hardening including a first step and a second step. In the first step, during continuously conveying the workpiece (11) in a horizontal direction without a space between adjacent workpieces (11), an entirety of the workpiece (11) is subjected to induction-heating conducted from an outside surface of the workpiece (11) only, and a temperature of the workpiece (11) is made uniform before the workpiece (11) reaches a cooling portion (13) spaced from a heating portion (12). Then, cooling the workpiece (11) is initiated before the temperature of the workpiece (11) falls to Ar3 temperature and an entire cross-section of a wall of the workpiece (11) is quench-hardened. In the second step, during continuously conveying the workpiece (11) in the horizontal direction, induction-heating is conducted only to an outside portion of the workpiece, the induction-heating being conducted from the outside surface only. Immediately after that, the workpiece is cooled from the outside surface thereby re-quench-hardening the outside portion, so that both the outside portion and the inside portion of the workpiece (11) have a hardness greater than an effective hardness, and a core portion of a wall of the workpiece has a hardness less than the effective hardness.
More Like This:
Inventors:
Isao Yoshida
Kimio Goto
Hiroyuki Takeno
Masahiro Nakajima
Kimio Goto
Hiroyuki Takeno
Masahiro Nakajima
Application Number:
JP101099A
Publication Date:
November 26, 2008
Filing Date:
January 06, 1999
Export Citation:
Assignee:
Topy Industries, Ltd.
International Classes:
C21D1/10; C21D1/18; C21D9/00; C21D9/08; C21D1/78
Domestic Patent References:
| JP3166320A | ||||
| JP9143564A |
Attorney, Agent or Firm:
Keio Tabuchi