P91钢的形变强化行为  

Strain hardening behavior of P91 steel

作　　者：刘江南[1] 王正品[1] 束国刚[2] 石崇哲[1] 

机构地区：[1]西安工业大学材料与化工学院,陕西西安710032 [2]苏州热工研究院,江苏苏州215004

出　　处：《金属热处理》2009年第1期28-32,共5页Heat Treatment of Metals

基　　金：陕西省自然科学基金(2001C55)

摘　　要：采用静力拉伸试验法研究了P91钢在566℃和室温时的形变强化与组织结构变化规律。结果表明,P91钢在室温条件下拉伸时自屈服至颈缩前的均匀塑性变形过程中的形变强化分3个阶段,颈缩至断裂前的局集塑性变形过程中的形变强化也分3个阶段。而在566℃时自屈服至颈缩前的均匀塑性变形过程中的形变强化为2个阶段。在局集塑性变形过程中,回火板条马氏体顺拉伸方向伸长变形的相对伸长量与颈缩量成双对数线性关系,马氏体板条束的位向朝拉伸方向转动的位向角与颈缩量也成双对数线性关系。塑性变形时位错组态出现胞状结构,随塑性变形量的增大,位错胞尺寸减小,并且顺拉伸方向伸长。形变强化能力决定了该钢在室温时的抗过载能力强。The mechanism of strain hardening and microstructures of P91 steel at 566℃ and room temperature were studied by means of static tensile test. The results show that the strain hardening processes during uniform plastic range from yielding to necking are divided into as three stages as localized plastic range from necking to fracture at room temperature, while the deformation from yielding to necking is divided into two stages at 566℃. The relationship between the relative elongation of tempered lath martensite in tensile direction and the necking percentage is linear double logarithmic, so is the relationship between the rotating angle of martensite lath clusters to tensile direction and the necking percentage. During plastic deformation dislocation cells form and with the increase of plastic deformation, the size of dislocation cells decrease and elongate along tensile direction. The ability of strain hardening induces strong overload resistance at room temperature.

关 键 词：P91钢 均匀塑性变形 局集塑性变形 形变强化 形变强化指数 位错胞 

分 类 号：TG113.25[金属学及工艺—物理冶金]