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研究了淬火-等温-回火（Q-I-T）新工艺对60Si2CrVA弹簧钢显微组织的影响。通过残余奥氏体（AR）的测定、金相观测和TEM分析研究。结果表明：淬火-等温（Q-I）处理后的残余奥氏体以薄膜状分布于马氏体、贝氏体束条之间，其显微组织由针束状马氏体M+过渡形态的条束状贝氏体B+残余奥氏体AR薄膜组成,本工艺条件下，其各组织的体积分数为：50～60%马氏体+30～40%贝氏体+回火后小于10%残留奥氏体，其中贝氏体条宽度在100～500nm之间，亚单元尺寸在50～250nm之间。与传统淬火回火工艺相比，新工艺组织得到分割细化，并获得复相组织，有利于弹簧钢具有更好的强韧性配合。

The effect of quenching-isothermal-tempering（Q-I-T）on microstructure of 60Si2CrVA spring steel was studied in this paper. The volume fraction of retained austenite (AR) was measured by XRD and the microstructures of all samples were analysed by metallurgical microscopy and TEM. The results show that the retained austenite is film-like distribution between the laths and packets of the martensite and bainite after Q-I heat treatment，the microstructure is fine-acicular or lath martensite (M) +transitional lath bainite (B) + retained film austenite(AR) and its volume fraction of the respective microstructure is: 50~60%martensite+30~40%bainite+less than 10%retained austenite after tempering, the width of bainite lath is 100~500nm and the sub-unit size is 50~250nm. Compared with conventional heat treatment, the structure is refined and the duplex microstructure is obtained in 60Si2CrVA spring steel by the new heat treatment, it is useful to improve the strength, plasticity and toughness of the spring steel.