摘要
采用不同的送丝速度对X90管线钢进行激光/MAG复合对接焊试验,利用扫描电镜对焊接接头进行组织及冲击断口观察,对接头进行拉伸、冲击及硬度试验,并通过电化学试验评价其耐蚀性。结果表明,随着送丝速度的增加,焊缝区及粗晶区晶粒有长大趋势;随送丝速度的增大,接头抗拉强度呈现先降低后升高趋势,而冲击韧性降低;送丝速度为8.5 mm/s时,接头的抗拉强度及冲击吸收功最高,分别为816 MPa、239.10 J;接头硬度分布呈现自焊缝中心至母材先降低后升高的趋势,硬度值最低区域出现在热影响区;接头焊缝区及母材均未出现明显的钝化行为,随送丝速度的增加,焊接接头耐蚀性逐渐降低,母材的自腐蚀电位明显高于3组接头焊缝区的自腐蚀电位。
The laser-MAG hybrid butt welding experiments of X90 pipeline steel were carrid out by using different wire feeding speeds. The microstructure and impact fracture of the welded joints were observed by SEM, the tensile, impact and hardness tests of the joints were carried out, and the corrosion resistance was evaluated by electrochemical tests. The results show that the grain size of weld zone and coarse grain zone increases with the increase of wire feeding speed. With the increase of wire feeding speed, the tensile strength of the joint decreases firstly and then increases, while the impact toughness decreases. When the wire feeding speed is 8.5 mrn/s, the tensile strength and impact absorption energy of the joint are the highest, which are 816 MPa, and 298.87 J/cm2 respectively. The hardness distribution of the joints shows the trend of decreasing firstly and then increasing from the weld center to the base metal, and the lowest hardness values appear in the heat affected zone. There is no obvious passivation behavior in weld zone of the joint and base metal, the corrosion resistance of the welded joint decreases with the increase of the wire feeding speed, and the corrosion potential of the base metal is higher than that of weld zone of the 3 group of joints.
作者
周志民
康全
张军磊
杨眉
ZHOU Zhimin, KANG Quan, ZHANG Junlei, YANG Mei(School of Material Science and Engineering, Southwest Petroleum University, Chengdu 610500, Chin)
出处
《热加工工艺》
CSCD
北大核心
2018年第5期186-189,193,共5页
Hot Working Technology
基金
四川省油气田材料重点实验室开放基金资助项目(X151516KCL27)
大学生课外开放实验项目(KSZ16101)
关键词
X90
送丝速度
组织
耐蚀性能
X90
wire feeding speed
microstructure
corrosion resistance
