小径厚壁12Cr1MoVG钢管焊接接头裂纹分析及其控制  

Crack Analysis and Control of Welded Joints of Small Diameter Thick Wall Steel Pipes of 12Cr1MoVG

作　　者：司耀强 李军 武勇 耿韶武 王涛 张昌胜 SI Yao-qiang;LI Jun;WU Yong(Shandong Energy Inner Mongolia Sheng Lu Electric Power Co.,Ltd.)

机构地区：[1]山东能源内蒙古盛鲁电力有限公司,内蒙古鄂尔多斯016299

出　　处：《电站系统工程》2024年第2期80-82,共3页Power System Engineering

摘　　要：通过宏观形貌、化学分析、金相检验、硬度检测和扫描电镜观察,研究在环境温度低、风力大且没有焊前预热的条件下小径厚壁12Cr1MoVG钢管焊接接头裂纹产生原因。结果表明:在环境温度低,没有焊前预热,且焊接线能量高的情况下,焊缝处残余应力增加,而塑性变形能力减弱,再加之奥氏体晶界处空穴的出现,导致焊缝打底层垂直于焊缝方向横向开裂。对于小径厚壁12Cr1MoVG钢管,可通过焊前预热、控制层间温度、焊后热处理、调整焊接参数和减小焊接热输入量等方式来有效避免焊缝开裂。Through macro-morphology,chemical analysis,metallographic examination,hardness testing and scanning electron microscope observation,the properties and causes of cracks in welded joints of small-diameter thick-walled pipes of 12Cr1MoVG under the condition of low temperature and no preheating were studied.The results showed that under the low ambient temperature,no preheating before welding,and high heat input of the welding line,the residual stress at the weld seam increased and the plastic deformation capacity weakened.Furthermore,the appearance of vacancies at the austenite grain boundaries resulted in transverse cracking of the weld root layer perpendicular to the weld direction.For small-diameter thick-walled 12Cr1MoVG steel pipes,cracking of the weld seam can be effectively avoided by preheating before welding,controlling the interlayer temperature,post-weld heat treatment,adjusting the welding parameters,and reducing the welding heat input.

关 键 词：12Cr1MoVG钢 小径厚壁管 焊前预热 焊接线能量 残余应力 塑性变形能力 横向裂纹 

分 类 号：TK225[动力工程及工程热物理—动力机械及工程]