采用手工电弧焊对X80管线钢进行焊接,对焊接接头进行不同温度的焊后深冷处理,通过金相分析、硬度测试、拉伸试验、冲击试验等研究深冷处理对X80管线钢焊接接头组织及力学性能的影响。结果表明,经深冷及回火处理后,X80钢焊接接头组织由铁素体和奥氏体逐渐向回火索氏体转变。X80管线钢经过深冷处理后,其焊接接头综合力学性能得到较大提高,且深冷温度越低,综合力学性能越好;在-196℃深冷处理条件下,焊接接头抗拉强度及冲击吸收能量较未处理试样分别提高约11.1%和72.8%,断裂方式由脆性准解理断裂转变为韧性断裂。 The X80 pipeline steel was welded by hand arc welding and the post-weld cryogenic treatment was carried out on the welded joints. The microstructure and mechanical properties of the welded joint of X80 pipeline steel were studied by means of metallographic analysis, hardness test, tensile test and impact test. The impact of performance. The results show that after cryogenic and tempering treatment, the microstructure of X80 steel welded joint changes from ferrite and austenite to tempered sorbite gradually. X80 pipeline steel after cryogenic treatment, the mechanical properties of the welded joints have been greatly improved, and the cryogenic temperature is lower, the better the comprehensive mechanical properties; under -196 ℃ cryogenic treatment conditions, the tensile strength and impact energy absorption of welded joints Which is about 11.1% and 72.8% higher than that of the untreated sample, respectively. The fracture mode changed from brittle quasi-cleavage fracture to ductile fracture.