【摘要】 本研究首先摸索了磁性法测残余奥氏体所需的标样处理工艺 ,认为GCr15钢经10 5 0℃淬火 ,-78℃× 1.5h深冷处理 ,2 80℃× 2 0min回火可得到全马氏体组织。用该标样测定不同工艺处理GCr15钢的残余奥氏体量 ,虽然各工艺的淬火温度不同 ,但经 >15 0℃回火后 ,回火马氏体的碳含量将趋于一致。经 85 0℃淬火 ,180℃、2 0 0℃、2 3 0℃、2 60℃、2 80℃分别回火 10min、2 0min、3 0min后GCr15钢组织中残余奥氏体含量的变化趋势与资料曲线相吻合。经 85 0℃淬火 ,2 0 0℃× 2 0min回火后 ,钢中残余奥氏体量为 10 %左右 ,满足使用要求。统一标样磁性法已被实践证明简便可行。更多还原

【Abstract】 Heat treatment process of standard specimen for the measurement of retained austenite by means of magnetic method has been explored in this paper.The concerned research shows that quenching from 1050℃,deep cryogenic treatment of-78℃×1.5h and tempering of 280℃×20min are capable of helping GCr15 steel to obtain complete martensite.Retained austenite measurement of GCr15 steel treated by different processes demonstrates that carbon content in martensite tempered at >150℃ is identical in spite of the different quenching temperatures of these processes.The change trend of retained austenite content in GCr15 steel quenched from 850℃ and tempered respectively at 180℃,200℃,230℃,260℃,or 280℃ for 10min,20min or 30min is identical with the curves in the document. The retained austenite content of GCr15 steel quenched from 850℃ and tempered at 200℃ for 20min is about 10% and therefore satisfies the service requirement.The measurement of retained austenite by unified standard specimen and magnetic method has been proved simple and easy in practice.更多还原