摘要
结合膨胀法和金相-硬度法,利用Gleeble-1500D热模拟机测定了42CrMoA钢的临界点Ac1、Ac3和Ms点,测定了该钢在不同冷却速度下连续冷却时的膨胀曲线,相转变点;分析了连续冷却过程中过冷奥氏体转变过程及转变产物的组织形貌;测定了不同冷却速度下相转变后的硬度,获得了该钢过冷奥氏体连续冷却相转变曲线。结果表明,当冷却速度小于0.1℃/s时,转变产物为铁素体和珠光体组织;当冷却速度0.2～0.6℃/s时转变产物是铁素体、珠光体、贝氏体的混合组织;当冷却速度为0.7～17℃/s时,转变产物是贝氏体和马氏体的混合组织;当冷却速度大于20℃/s时,转变产物为完全马氏体,此次实验并没有获得完全贝氏体。
The critical transition temperature Ac~, At3 and Ms of 42CrMoA steel was determined by Gleeble-1500D thermal simulation testing machine using dilatometric method combining with metaUographichardness method. The inflation curve and phase transition point of the steel under different cooling speed of continuous cooling was determined. The continuous cooling process and the product microstructure morphology of cold austenitic transformation was analyzed. The vickers-hardness of these products under different cooling rates were measured. The CCT diagram was obtained. The products of austenite transform were ferrite and pearlite when the cooling rate is lower than 0.1 ℃/s. Those would be ferrite, pearlite and bainite when the cooling rate is in the range of 0.2 to 0.6 ℃/s. Those would be bainite and martensite when the cooling rate is in the range of 0.7 to 17 ℃/s and those would be total martensite if the cooling rate is higher than 20 ℃/s. However, the total bainite in the sample microstructure is not obtained in the experiment.
出处
《热加工工艺》
CSCD
北大核心
2012年第22期83-85,共3页
Hot Working Technology
