高温时效对00Cr13Ni6Mo2不锈钢组织及性能的影响

Effect of high temperature aging on microstructure and mechanical properties of 00Cr13Ni6Mo2 stainless steel

采用拉伸试验、X射线衍射、光学显微镜和透射电镜等研究了一种13Cr超级马氏体不锈钢(00Cr13Ni6Mo2)的高温力学性能和高温时效后的力学性能、物相组成及显微组织。结果表明:00Cr13Ni6Mo2钢在高温下可保持较高的屈服强度,但当超过Af(奥氏体转变完成点)温度后,屈服强度迅速下降;600℃时效后,马氏体基体中的位错密度明显降低,同时产生了一定量的逆变奥氏体,导致时效100 h后其屈服强度从824 MPa降至682 MPa(下降17.2%),而抗拉强度和伸长率变化不大;800℃时效过程中,试验钢的组织完全奥氏体化,在降温过程中组织转变为淬火马氏体,故其具有典型的淬火马氏体性能特征,时效100 h后抗拉强度从858 MPa升至1031 MPa(提高20.2%),同时伸长率从22.5%降至15.0%。

The high temperature mechanical properties and the mechanical properties,phase composition and microstructure after high temperature aging of a 13 Cr super martensitic stainless steel(00 Cr13 Ni6 Mo2)were studied by means of tensile test,X-ray diffraction,optical microscope and transmission electron microscopy.The results show that the 00 Cr13 Ni6 Mo2 steel can maintain high yield strength at high temperature,but the yield strength decreases rapidly when the temperature exceeds the temperature of Af(austenite transformation completion point).After aging at 600℃,the dislocation density in the martensite matrix decreases obviously,and a certain amount of inverted austenite is produced,which leads to the yield strength of the steel decreasing from 824 MPa to 682 MPa(decreases by 17.2%)after aging for 100 h,but the tensile strength and elongation do not change much.During the aging process at 800℃,the microstructure of the steel is completely austenitized,and the microstructure is transformed into quenched martensite during the cooling process,so it has typical properties of quenched martensite.After aging at 800℃for 100 h,the tensile strength of the steel increases from 858 MPa to 1031 MPa(increases by 20.2%),and the elongation decreases from 22.5%to 15.0%.