MANUFACTURE OF AUSTENITIC STAINLESS CAST STEEL PART ENABLING ULTRASONIC FLAW DETECTION

摘要

PURPOSE:To manufacture the titled part superior in ultrasonic transparency, by converting a region requiring ultrasonic flaw detection in austenitic stainless cast steel part contg. a specified quantity of ferrite phase to unidirectional solidified structure, and applying cold working by a specified draft and recrystallization heat treatment in order. CONSTITUTION:Cast structure in the region requiring at least ultrasonic flaw detection in austenitic stainless cast steel part having ferrite phase of =5vol%, is converted to unidirectional solidified structure from outer surface by using e.g. chiller. Then, the region of cast part approximated to the final product shape as material is cold worked by =5%-10% draft then recrystallization heat treated. In this way, austenitic stainless cast steel part such as valve superior in ultrasonic transparency is obtd.