应力对T91铁素体耐热钢低温相变过程的影响  

Effect of Stress on Low Temperature Phase Transformation of T91 Ferrite Heat Resistant Steel

作　　者：宁保群[1] 刘永长[1] 乔志霞[1] 杨留栓[2] 

机构地区：[1]天津大学材料科学与工程学院,天津300072 [2]平顶山工学院材料科学与工程系,河南平顶山467001

出　　处：《钢铁》2007年第9期68-71,84,共5页Iron and Steel

基　　金：国家自然科学基金资助项目(50401003);全国优秀博士论文作者专项基金(200335);天津市自然科学基金资助项目(033608811);河南省国际合作项目(0546620015)

摘　　要：采用Baehr DIL805A/D高精度差分膨胀仪测量线膨胀行为与微观组织分析获取了T91铁素体耐热钢低温相变过程动力学信息,研究了不同温度(760、650和440℃)下施加不同压应力(100、150和200 MPa)对低温相变过程的影响。研究结果表明:压应力的施加促使马氏体的形成,提高Ms点;但在不同温度下应力的施加对Ms点的影响不同:随应力的增加,温度为760和650℃时,Ms呈降低趋势;在440℃下Ms点起先不发生变化而后呈升高趋势。这是因为在760和650℃时,相变机制主要与形变奥氏体的形态有关;而在440℃下主要受应力诱导马氏体相变机制的影响。The effect of stress applied at certain temperature on low temperature phase transformation of T91 was studied with Baehr DIL805A/D high-resolution differential dilatometer. According to the results of dilatometric measurement and microstructure observation, kinetics of phase transformation was obtained. It was found that the stress promotes formation of martensite and increase of Ms ; but the stress applied at different temperature exhibits different effect on Ms： with increase of stress,at 760 ℃ and 650℃ Ms decreases, whereas at 440 ℃ Ms is constant at first and increases afterwards. The above phenomena could be accounted for the different inherent phase transformation mechanism： the former is controlled by the morphology of the deformed austenite,the latter is influenced by stress induced martensite transformation.

关 键 词：压应力 T91铁素体耐热钢 形变奥氏体 应力诱导马氏体 

分 类 号：TG142.73[一般工业技术—材料科学与工程]