【摘要】 研究了强度级别为1900MPa的新型马氏体不锈钢在经过不同制度的热处理后的微观组织及其对钢力学性能的影响。试验钢经1000℃固溶处理后在基体上有一种富Mo的析出物生成,这种析出物降低了钢时效后的韧性。经1000℃,1050℃固溶处理+负温处理后,试验钢在535℃时效处理时强度均达到最大值,原因是在高密度位错的板条马氏体和残余奥氏体基体上析出均匀弥散、细小的强化相。随着时效温度继续升高强度开始下降,其原因有二,其一析出相聚集长大,破坏了与基体间原有的共格关系;其二逆转变奥氏体转变量的增加。更多还原

【Abstract】 Effect of mierostructures in a new-type martensitic stainless steel with strength level of 1900 MPa and heat-treated by different processes on its mechanical properties has been studied.A molybdenum-enriched precipitate will produce in matrix of the tested steel solution-treated at 1000℃,with the toughness of the steel after being aged reduced.After being solution-treated at 1000℃,1050℃ and subsequent subzero treating the steel aged at 535 ℃ possesses maximum strength,which stems from uniformly precipitating fine and disperse strengthening phase in both lath martensite with high density dislocation and residial austenite.With further increase in aging temperature the strength will decrease,which rusults from the following two reasons: ⑴Coarsening of the precipitated phase destroys coherent relation with the matrix;⑵ Reverted austenite content increases.更多还原