【摘要】 研究了一次淬火马氏体对低合金钢经淬火和配分(Quenching and Partitioning,Q&P)工艺后微观组织和单轴拉伸性能的影响,用扫描电镜进行微观组织表征,用X射线法测量残留奥氏体量。试验结果表明,随着一次淬火马氏体比例的增加,二次淬火马氏体的尺寸和数量逐渐减少,残留奥氏体体积分数呈先增加后减少的趋势,一次淬火马氏体体积分数为40%时获得最大残留奥氏体体积分数为16.92%。一次淬火马氏体体积分数为30%~70%时试验钢获得了较高的塑性和强塑积,马氏体基体为钢提供了高强度,残留奥氏体在变形过程中的TRIP效应提高了钢的塑性。更多还原

【Abstract】 Effects of initial martensite on the microstructure and mechanical properties of quenching and partitioning(Q&P)low alloy steel were investigated. The microstructure characterization and austenite fraction measurement were carried out in scanning electron microscopy and X-rays diffraction. It was found that with increasing fraction of initial martensite,the size and amount of fresh martensite decreased gradually,and the volume fraction of retained austenite increased firstly and then decreased,the maximum volume fraction of retained austenite of 16.92% was obtained when the initial martensite fraction was 40%. The higher ductility and the product of the tensile strength to total elongation could be obtained with the initial martensite fraction ranging from 30%-70%,the martensite matrix of steel guaranteed the high strength,and the TRIP effect of retained austenite during deformation improved the ductility of steel.更多还原