1Cr12Ni3Mo2VN耐热钢的回火工艺

利用金相显微镜、扫描电镜和透射电镜等研究了1Cr12Ni3Mo2VN耐热钢的回火工艺,结果指出试验钢产生第一类回火脆性的主要原因是马氏体板条界存在聚集长大的Fe_3C及M_3C脆性相,导致冲击韧性显著下降。Mo_2C与基体处于共格状态,使基体周围晶格产生很大的静畸变是次要原因;产生第二类回火脆性的原因,一是由于碳化物M_(23)C_6沿原奥氏体晶界和马氏体板条界迅速聚集并粗化,二是板条间残余奥氏体膜因碳贫化而发生热失稳分解。结合技术协议要求,为了有利于组织的稳定性,本试验钢的最佳回火工艺为580℃×2h空冷。

Temper technics of heat-resistant steel 1Cr12Ni3Mo2VN

The temper technics of heat-resistant steel 1Cr12Ni3Mo2VN was investigated by metalloscopy,SEM and TEM.The results show that a large number of carbide Fe3 C and M3 C growing along the martensite lath border is the main reason that caused No.1 temper embrittlement,the static distortion caused by Mo2 C and matrix in a co-herent state is secondary reason;a large number of carbide M23 C6 growing together along austenitic grain bounda-ry and the martensite lath border and the thermal decomposition of retained austenite are the main reasons for the No.2 temper embrittlement.Combined with the technical agreement requirements,in order to benefit the stability of organization,the optimal temper technics is 580℃×2 h by air cooling.