焊接二次热循环对X90管线钢组织和性能的影响  

Influence of Secondary Welding Themal Cycle on Structure and Properties of X90 Pipeline Steel

作　　者：赵波 张卫东 孙奇 ZHAO Bo;ZHANG Weidong;SUN Qi(CNPC Bohai Equipment Research Institute,Qingxian 062658,Hebei,China;North China Petroleum Steel Co.,Ltd.,CNPC Bohai Equipment Manufacturing Co.,Ltd.,Qingxian 062658,Hebei,China;CNPC Bohai Equipment Steel Pipe Sales Co.,Ltd.,Qingxian 062658,Hebei,China)

机构地区：[1]渤海装备研究院,河北青县062658 [2]渤海装备华油钢管公司,河北青县062658 [3]渤海装备钢管销售公司,河北青县062658

出　　处：《焊管》2020年第3期1-7,共7页Welded Pipe and Tube

摘　　要：针对X90管线钢焊接过程中二次热循环作用下,焊缝热影响区易产生脆化的问题,采用热模拟技术研究了不同二次热循环峰值温度对X90管线钢焊接粗晶区性能的影响。试验结果表明,一次峰值温度1350℃作用下,再经过800℃二次热循环后,热影响区韧性显著下降,发生严重脆化,主要是由于该区遗传了粗晶区粗大的组织形态,同时沿原奥氏体晶界形成粗大、高度富碳、呈项链结构的M/A组元;X90管线钢一次热循环粗晶区经峰值温度为950℃的二次热循环后,晶粒细小,组织分布较为均匀,低温冲击韧性较好。In view of the embrittlement of HAZ of X90 pipeline steel under the secondary thermal cycle in the welding,the effect of the different peak temperature of the secondary thermal cycle on the properties of the welding coarse-grained zone of X90 pipeline steel was studied by means of the thermal simulation technology.The experimental results show that the toughness of the HAZ decreases significantly and embrittlement occurs seriously after a peak temperature of 1350℃and a second thermal cycle at 800℃.The main reason is that the coarse-grained structure is inherited in this region,and the M/A component with the coarse,high carbon rich and necklace structure is formed along the grain boundary of the original austenite;After the second thermal cycle with the peak temperature of 950℃,the coarse grain area of X90 pipeline steel in the primary thermal cycle is fine,the structure distribution is uniform,and the impact toughness at low temperature is good.

关 键 词：X90管线钢 热模拟 焊接热影响区 二次热循环 脆化 

分 类 号：TG456.3[金属学及工艺—焊接]