13Cr超级马氏体不锈钢的组织

Microstructure of 13Cr super martensitic stainless steel

采用TEM、SEM等研究13Cr超级马氏体不锈钢不同热处理后的的显微组织。结果表明,试验用钢淬火后的组织为板条马氏体。800、850、900、950、1000、1050和1100℃淬火后试样原始奥氏体晶粒尺寸为16.8～56.88μm;随淬火温度的升高原始奥氏体晶粒逐渐长大,马氏体板条束逐渐粗大。不同温度淬火650℃回火,A钢和B钢的组织均为保留原马氏体位相的细小回火马氏体。试样在1050℃淬火并在不同温度回火后有逆变奥氏体产生,在650℃以下回火时随着回火温度的升高和保温时间的延长逆变奥氏体含量逐渐增多,且回火后逆变奥氏体主要以长条状及菱形状分布于马氏体板条束间及奥氏体晶界处。

Microstructure of 13Cr super martensitic stainless steels after different heat treatments was studied by means of TEM and XRD.The results show that the microstructure of the steels after quenching is lath martensite matrix.The prior austenite grain size is from 16.8 μm to 56.88 μm for the steels quenched at 800-1100 ℃.The prior austenite grain size and the size of martensite lath bundle increase with the raising of quenching temperature.When the steels are tempered at 650 ℃ after quenching at different temperatures,the microstructure is fine tempered martensite retaining the morphology of quenched martensite.Reversed austenites with strip and diamond shape is observed along the boundary of prior austenite and lath boundaries of martensite in the steels quenched at 1050 ℃ and then tempered at different temperatures.When the samples are tempered at temperature lower than 650 ℃,the volume fraction of reversed austenite is increased with the increase of tempering temperature and time.