38CrMoAl钢奥氏体晶粒长大动力学研究

来源期刊：钢铁2010年第12期

论文作者：周超 王毛球 董瀚 王连海 董冰 吴润

文章页码：73 - 76

关键词：渗氮钢； 晶粒长大； 激活能； AlN析出相

Key words：nitrided steel； austenite grain growth； activation energy； AlN precipitate

摘    要：研究了VAR和EAF两种不同洁净度的38CrMoAl渗氮钢的奥氏体晶粒长大动力学。将38CrMoAl试验钢加热到940℃和1 000℃奥氏体化,并保温15～600 min,利用金相试验方法观察奥氏体晶粒的变化。结果发现,随着奥氏体化温度的升高和保温时间的延长,38CrMoAl钢晶粒长大趋势较明显;高洁净度的38CrMoAl钢(VAR)中AlN第二相颗粒较少,钉扎晶界作用弱,因而晶粒更易于长大。VAR和EAF两种洁净度的38CrMoAl钢奥氏体晶粒长大激活能分别为193 kJ/mol和321 kJ/mol。

Abstract: Kinetics of austenite grain growth was investigated for 38CrMoAl nitriding steels prepared by electric arc furnace(EAF) and vacuum arc remelting(VAR),respectively.The specimens were first austenitized at 940 ℃ and 1 000 ℃ for a holding time in the range of 15-600 min,and then quenched into water.Prior austenite grains of the specimens were observed by standard metallographic technique.The results show that the austenite grains of the experimental steels grow evidently with the increase of austenitizing temperature and holding time.The VAR specimens grow more evidently than the EAF specimens in the same austenitizing condition,since they have less AlN precipitates and the pinning effect of AlN precipitates on the austenite grain growth is weaker.The values of activation energy for austenite grain growth are measured to be 193 kJ/mol and 321 KJ/mol for the VAR and EAF specimens,respectively.