Clever control methods of heat treatment distortion in Oil Quenching

Abstract,

            The accuracy of the components is important to manufacture precision parts same as hardness and effective case depth. And heat treatment distortion is closed up as various efforts are devoted to reduce distortion.

There are many factors results in considerably large distortion that causes additional final grinding, such as steel chemical composition and ingot casting stage to final quenching operation.

Oil quench is the most popular methods to cool and harden steel components While the R & D in quenching oils have long history starting from early 20 century. The importance of characteristic of quench oil is not well understood even today.

In Japan leading basic research started in 1950’s by Prof. Tagaya and Tamura⁽¹⁾ made great contribution to the advancement of cooling and quench research.

Based on the application of National standard JIS 2242 in 1965 various quench oils have been introduced and contributed to improve the quality of heat treatment processes.

            In this paper, the important technology to reduce quench distortion by optimization of cooling process in relation with Quench Oil characteristics will be explained. The vapor blanket stage in oil quenching are not favored generally. But it is quite important to cool small mass on thin shaped portion by the adjustment of vapor blanket stage have quite important influence to reduce distortion. While the general understanding are not favor the vapor blanket stage.

Key words: Oil quench, Cooling control, Vapor blanket stage, Distortion.