SHORT TIME HIGH FREQUENCY HEAT TREATING METHOD FOR ALPHA + BETA TYPE TITANIUM ALLOY

摘要

PROBLEM TO BE SOLVED: To execute satisfactory heat treatment by heating in a short time and to improve the working efficiency without deteriorating the quality of the article to be heat-treated by subjecting an + type titanium alloy to short time heating by high frequency induction heating and rapidly cooling it to form ' phases. SOLUTION: A work coil is arranged in the vicinity of the surface of an + type titanium alloy, which is subjected to short time heating at 800 to 1200 deg.C for 1 to 600 sec by high frequency induction heating by the frequency of 1 to 400 kHz and is thereafter rapidly cooled to form ' phases. It is more desirable that, as for the frequency of the high frequency voltage, furthermore, the lower limit is regulated to 3 kHz and the upper limit to 200 kHz. In this way, by the increase of the plastic deformation resistance accompanied by the formation of the ' phases, the yield strength, tensile strength and fatigue strength of the +type titanium alloy improve, by which the production efficiency can remarkably be improved without deteriorating the quality of the article to be treated.