| 摘要 |
PURPOSE:To fine austenite particles and improve hot workability by decreasing the Nb content of the Nb-contained austenite-base stainless steel to 1.5-4 times the C content and applying solution-heat treatment at the specific temperature. CONSTITUTION:The amount of Nb to be contained in the austenite-base stainless steel is reduced from conventional 10 times the C content to 1.5-4 times and is made 0.3% or less. This stainless steel is subjected to working such as hot forging, after which it is subjected to solution-heat treatment at the temperature range T deg.C which satisfies 900 deg.C<=T deg.C<=250 deg.CXNb%+1050 deg.C. This yields the fine austenite particles of ASTM grain size number No. 3 or more in which the recrystallization of austenite particles has sufficiently completed, the relief of strain is sufficient and the recrystallization grain size of austenite has no inconveniences at all in the nondestructive testing of ultrasonic flaw detection, whereby the austenite-base stainless steel for hot working may be produced. |
