When the bainite transformation the formation simultaneous austempering

摘要

PROBLEM TO BE SOLVED: To provide a method for simultaneous forming and austempering treatment for steel by which excellent productivity can be attained. ;SOLUTION: The method for simultaneous forming and austempering treatment for steel comprises: a heating step 11 where steel is heated to a temperature not lower than the austenitic transformation point; a cooling step 12 where the austenitized steel is cooled at a cooling velocity at which no pearlitic transformation is brought about to be formed into supercooled austenitic state; a holding step 13 where the supercooled austenitic state of the cooled steel is held for a prescribed period of time; and a simultaneous forming and heat treatment step 14 where, after the above holding step, the steel is subjected to plastic working simultaneously with bainitic transformation. Moreover, the above steps are carried out using different devices.;COPYRIGHT: (C)2003,JPO