热处理工艺对300M超高强度钢组织和性能的影响  

Effect of heat treatment on microstructure and properties of 300M ultrahigh strength steel

作　　者：彭雯雯[1] 曾卫东[1] 康超[1] 贾志强[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《材料热处理学报》2012年第3期94-98,共5页Transactions of Materials and Heat Treatment

基　　金：新世纪优秀人才支持计划(NCET-07-0696)

摘　　要：采用SEM、TEM等方法研究了不同回火温度对300M超高强度钢的显微组织和力学性能的影响。结果表明,300M钢经870℃淬火后,在290～320℃范围内回火,显微组织为板条马氏体、下贝氏体和残留奥氏体组成。随着回火温度的升高,板条马氏体宽度由260 nm增加到437 nm,位错密度减小,下贝氏体含量增多;合金的抗拉强度有所下降,韧性呈上升趋势,而屈服强度、伸长率和断面收缩率变化较小。当回火温度为300℃时,强度、塑性和韧性达到一个最佳匹配,合金具有最优的综合力学性能。Effect of different tempering temperature on microstructure and mechanical properties of 300M ultrahigh strength steel was investigated by using transmission electron microscopy（TEM） and scanning electron microscopy（SEM）.The results show that the microstructure of 300M ultrahigh strength steel consists of tempered martensite,lower bainite and residual austenite after quenching at 870 ℃ followed by tempering at 290-320 ℃.With tempering temperature increasing,the width of lath martensite increases from 260 nm to 437 nm,the density of dislocation decreases and the amount of lower bainite increases.The tensile strength of 300M steel declines and its impact toughness increases,however,the yield strength,elongation and area reduction are nearly unchanged with the increase of tempering temperature.The optimal mechanical properties of 300M ultrahigh strength steel can be obtained by tempering at 300 ℃.

关 键 词：300M超高强度钢 回火温度 显微组织 力学性能 

分 类 号：TG146.4[一般工业技术—材料科学与工程]