27SiMnMoVB钢中粒状贝氏体形成及其回火转变的研究  

Study on the Formation and Temper Transformation of Granular Bainite Structure in 27SiMnMoVB

作　　者：顾艳[1] 常红英[1] 

机构地区：[1]宝钢特钢分公司质量保证部,上海200940

出　　处：《金属材料研究》2009年第2期6-13,共8页Research on Metallic Materials

摘　　要：利用金相、透射电子显微镜技术、OTM图像分析等方法，研究了27SiMnMoVB在不同热处理制度下的组织形态、残余奥氏体的含量及其转变产物，并探索了粒状贝氏体的形成机理及强化机理。结果表明，粒状贝氏体中的残余奥氏体岛的形态与正火温度有关，随着正火温度的升高，岛状相由块状趋向条状。M／A相含量随冷速增大而增加。回火试验表明，粒状贝氏体中的残余奥氏体在低温回火时已部分转变为贝氏体。400℃回火时残余奥氏体分解为铁素体和碳化物，并在贝氏体一铁索体基体上析出碳化物，马氏体的分解温度在400-500℃之间，至650℃回火转变基本结束。在回火过程中试验材料无二次淬火现象，残余奥氏体含量随回火温度升高而下降。The microstructures, amount of residual austenite and transformation products of 27SiMnMoVB alloy under different heat treatments were investigated by metallography, transmission microscope and image analyzer. The mechanisms of formation and reinforcement of granular bainite were discussed. The results showed that the morphology of residual austenite island in granular bainite had relation with normalizing temperature. The shape of residual austenite island changed from block to strip with incerasing normalizing temperature. The amount of M/A microstructure increasessd with incerasing coiling rate. The tempering experiment results revealed that residual austenite in the granular bainite had transformed to bainite partly during low temperature tempering. The residual austenite had decomposed into ferrite and carbide at 400 ℃, and the carbide was precipitated from bainiteferrite matrix between 400 and 500 ℃, the transformation was finished at 650 ℃. There was no second quenching phenomenon during tempering and the amount of residual austenite reduced with incerasing tempering temperature.

关 键 词：27SiMnMoVB 粒状贝氏体 热处理 

分 类 号：TG142.2[一般工业技术—材料科学与工程] TG161.5[金属学及工艺—金属材料]