材料期刊网

采用热模拟技术和显微观察技术，对07MnCrMoVR钢热影响区的组织和性能进行了深入研究。研究结果表明：单次热循环时，粗晶区和临界区是韧性较差的区域，其中粗晶区的韧性恶化原因为晶粒的长大和粒状贝氏体、M-A组元等非平衡组织的形成，且随着t8/5的增加，粗晶区冲击韧性随之降低。为防止热影响区脆化，t8/5应控制在30s之内。粗晶区+临界区是二次热循环时热影响区韧性最差的区域，大量沿晶界分布的块状M-A组元的形成是此区域脆化的原因。

The mechanical properties and microstructure of 07MnCrMoVR heat affected zone was studied by thermal simulation technology and microstructure examination technology. The results indicated that coarsed grain zone and critical zone are the brittlement zones in heat affected zone during single thermal cycle testing, and the brittlement of caorsed grain zone ascribed to the grain coarsing and the formation of granular bainite and M-A constituent. With the increase of t8/5, the toughness of coarsed grain zone decrease, and it should be controlled in 30s in actual welding. The formation of lot of massive M-A constituents distributed along grain boundary is the main cause for the brittlement of intercritically reheated coarse grained HAZ