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通过熔化极气体保护焊的方法,采用准1.2 mm的T Union GM 120实芯气保焊丝对FGS90WV钢管进行对接焊,对焊接接头显微组织进行了观察,并对接头拉伸、弯曲、冲击、硬度等力学性能进行了检测。结果表明,焊缝区组织为少量先共析铁素体+针状铁素体,淬火区组织为马氏体;随着热输入增加,焊缝组织中先共析铁素体含量增多,热影响区组织逐渐粗化;接头抗拉强度和屈服强度先小幅增加后迅速降低,伸长率和冲击韧性逐渐降低,当热输入小于11.5k J/cm时,接头具有良好的强韧性匹配;热影响区硬度逐渐降低,焊缝区硬度几乎不受影响,当热输入达到23.5 k J/cm时,热影响区硬度大幅下降。
The welding of FGS90WV steel pipe with butt-welding of 1.2mm T Union GM 120 solid wire was carried out. The microstructure of the welded joint was observed and the tensile, flexural, Hardness and other mechanical properties were tested. The results show that the weld zone is composed of a small amount of pro-eutectoid ferrite + acicular ferrite and the quenched zone is martensite. With the increase of heat input, the pro-eutectoid ferrite content in the weld joint increases, and the hot The tensile strength and yield strength of the joint decreased first and then decreased sharply, and the elongation and impact toughness gradually decreased. When the heat input was less than 11.5k J / cm, the joint had good strength and toughness matching. The hardness of the affected zone gradually decreases and the hardness of the weld zone is almost unaffected. When the heat input reaches 23.5 kJ / cm, the hardness of the HAZ decreases sharply.