不同退火工艺对Nb-Ti微合金化TRIP钢组织及力学性能的影响研究

Effect of Different Annealing Processes on the Microstructure and Mechanical Properties of Nb-Ti Microalloyed TRIP Steel

利用盐浴热处理模拟了Nb-Ti微合金化TRIP钢在等温淬火和淬火配分工艺条件下的退火过程,采用拉伸试验机和电子探针对退火后的试验钢进行了力学和组织检测,结果表明,在等温淬火工艺下,试验钢可获得较高的延伸率,但强度偏低,790℃的退火温度所得到的综合力学性能最优,强塑积达到32.94 GPa·%;在淬火配分工艺条件下,随着退火温度升高试验钢抗拉强度略有降低,延伸率增加,当退火温度达到827℃时,试验钢抗拉强度急剧增加,延伸率急剧降低。退火温度为804℃时综合力学性能最优,强塑积达到最大值20.73 GPa·%。综合来看,在淬火配分工艺下试验钢能够在实现高强度的同时兼具良好的塑性。

The annealing process of Nb-Ti microalloyed TRIP steel under isothermal quenching and quenchingpartitioning process is simulated by salt bath heat treatment.The mechanical and microstructure of experimental steel after annealing are tested by tensile tester and electron probe.The results show that under isothermal quenching,the experimental steel has relatively high elongation,but the strength is low,the steel has the best comprehensive mechanical properties when the annealing temperature is 790℃,and the product of strength and elongation can reach 32.94 GPa·%.In quenching-partitioning process,with the annealing temperature increases,tensile strength declines slightly,and the elongation increases.The tensile strength increases sharply,and the elongation decreases sharply when the annealing temperature reaches 827℃.The steel has the best comprehensive mechanical properties when the annealing temperature is 804℃and the product of strength and elongation can reach 20.73 GPa·%.In summary,the experimental steel can achieve high strength and good plasticity under quenching-partitioning process.