增强型13Cr不锈钢经不同工艺调质后的显微组织和力学性能

Microstructure and Mechanical Properties of Enhanced 13Cr Stainless Steel after Different Quenching and Tempering Treatments

采用物相分析、组织观察、冲击和拉伸试验等方法研究了增强型13Cr不锈钢经三种不同工艺调质后的显微组织和力学性能,确定了最佳的调质工艺。结果表明:随着调质淬火温度的升高,试验钢的强度和伸长率逐渐下降,而冲击功则先升高再下降;试验钢经1 000℃×2 h空冷+600℃×2 h空冷的工艺调质后,其抗拉强度为787 MPa,屈服强度为746 MPa,伸长率为26%,冲击功为192 J,达到了API 5CT标准要求;在上述调质工艺处理后,试验钢形成了以板条马氏体为基体、残余奥氏体弥散分布于晶界的显微组织。

The microstructure and mechanical properties of enhanced 13Cr stainless steel treated by three different quenching and tempering processes were studied by microstructure observation, phase analysis, impact and tensile tests. The best quenching and tempering process was determined. The results show that the tensile strength and elongation of tested steel decreased gradually with the increase of quenching and tempering temperature, however, the impact toughness increased first and decreased later. After the quenching and tempering process of 1 000 ℃ AC and 600 ℃ AC, the tested steel had good mechanical properties （Rm=787 MPa, Rp0.2 =746 MPa, A= 26%, Ak= 192 J） which reached the requirement of API 5CT. The microstructure of the steel treated with the process was lath martensite as matrix with retained austenite distributed along the boundaries.