热输入对9Ni钢焊接接头组织及低温冲击性的影响  

Effect of heat input on microstructure and low temperature impact resistance of welded joint of 9Ni steel

作　　者：孟根巴根[1,2] 马成勇[2] 彭云[2] 田志凌[2] 林文光[1] 

机构地区：[1]内蒙古工业大学材料科学与工程学院,呼和浩特010051 [2]钢铁研究总院,北京100081

出　　处：《焊接学报》2010年第6期69-72,共4页Transactions of The China Welding Institution

基　　金：国家863高技术研究发展计划资助项目(2007AA03Z506)

摘　　要：采用不同焊接工艺对9Ni低温钢进行埋弧焊接,通过金相显微镜和扫描电镜对其焊缝和热影响区微观组织及断口形貌进行了观察,研究了热输入对焊缝组织及低温韧性的影响.结果表明,随着热输入的增大,9Ni钢的焊缝中枝晶偏析减弱,析出相含量减少,断口韧窝尺寸变大变深,使焊接接头低温冲击性升高.不同热输入下焊接接头各个部位-196℃的冲击吸收功也高于标准值,硬度均小于标准规定的400HV,均满足使用要求.研究结果对9Ni钢的实际焊接提供了理论依据,对正确制订焊接工艺具有一定的指导意义.9Ni steel was welded with submerged arc welding process,and the microstructure and fracture appearance of welded joints were analyzed. The effect of heat input on the microstructure and low temperature impact resistance of the joints was studied. The results show that with the increase of the heat input,dendritic segregation and precipitation phase in the weld reduce,and fracture dimples become larger and deeper,which make the impact resistance of the joints increase. The joints in different input can meet application requirements,which impact absorbing energy is superior to standard at-196 ℃ and hardness is inferior to 400 HV. The experiment results can be used as theoretic basis for making welding procedure of 9Ni steel.

关 键 词：9NI钢 热输入 焊接接头 显微组织 低温韧性 

分 类 号：TG115.28[金属学及工艺—物理冶金]