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采用Ni基焊条对9Ni钢进行手工电弧焊,焊后对焊接接头分别进行不同回火温度和回火时间处理,对不同回火条件下母材、热影响区的组织和硬度进行了分析比较。结果表明:9Ni钢焊接接头回火处理后,其主要组织为铁素体、回火马氏体和回转奥氏体,随着回火温度的升高和回火时间的增加,粗晶区组织由粗大板条马氏体转变为细小的板条马氏体;热影响区硬度随着回火温度和回火时间的增加而降低;粗晶区在580℃回火时马氏体板条边界明显析出回转奥氏体,随着回火时间的延长回转奥氏体的量增加,当回火时间大于4 h以后,回转奥氏体的量变化不大。
Ni-based electrode was used to carry out manual arc welding on 9Ni steel. After welding, the welded joints were treated with different tempering temperature and tempering time respectively. The microstructure and hardness of the base metal and heat affected zone were analyzed and compared under different tempering conditions. The results show that the main microstructure of 9Ni steel welded joint after tempering is ferrite, tempered martensite and revolving austenite. With the increase of tempering temperature and tempering time, From coarse lath martensite to small lath martensite; the heat affected zone hardness decreases with the increase of tempering temperature and tempering time; the coarse grain zone tempering at 580 ℃ martensite lath boundary The austenite was obviously precipitated, and the amount of austenite was increased with the extension of tempering time. When the tempering time was more than 4 h, the amount of austenite did not change much.