摘要
采用大功率激光器对16⊥20 mm的TC4钛合金厚板T型接头进行无坡口全焊透试验,分析了接头不同位置的显微组织和横截面的硬度分布。结果表明:当接头每侧的激光功率为16 kW,离焦量为+10 mm,焊接速度为0.96 m/min,光束角度为15°,偏移量为1.5 mm时,焊缝成型良好,两侧焊缝重叠深度适中,无气孔、未焊透和未熔合等缺陷。焊缝区为由晶界α相、片状α’相和晶间β相组成的粗大柱状晶;从焊缝区根部至上部柱状晶尺寸逐渐增加;热影响区组织呈现过渡形貌,近焊缝热影响区组织为尺寸较大的等轴晶,近母材热影响区等轴晶的尺寸减小,原始等轴α相数量增加。焊缝区的硬度高于热影响区和母材区,热影响区出现低硬度区;在T型接头截面纵向上,焊缝根部的硬度最高,随距腹板中心线的距离增大,硬度总体上降低,最后趋于稳定。
The full penetration welding test without groove of TC4 titanium alloy T-joint with the size of 16⊥20 mm was carried out by using high power laser welding machine. The microstructure of different positions and hardness distribution of the cross section of the joint were analyzed. The results show that when the laser power at both sides of the joint is 16 kW, the defocusing amount is +10 mm, the welding speed is 0.96 m/min, the beam angle is 15° and the offset is 1.5 mm, good weld forming without porosity, incomplete penetration and incomplete fusion was obtained. The weld zone is coarse columnar grains, which is composed of grain boundary α phase, lamellar α’ phase and intergranular β phase. The size of columnar grains gradually increases from the weld root to the weld upper part. The microstructure of heat affected zone presents transition morphology. The microstructure of the heat affected zone near the weld is equiaxed grains with large size, while the size of equiaxed grains of the heat affected zone near the base metal decreases and the proportion of the original equiaxed αphase increases. The hardness of the weld zone is higher than that of the heat affected zone and the base metal zone, and low hardness zone appears in the heat affected zone. Along the longitudinal direction in section of the T type joint, the hardness of the weld root is the highest, and the hardness decreases generally and finally tends to be stable with the increase of the distance from the web centerline.
作者
马照伟
刘甲
付占波
雷小伟
高奇
崔永杰
张云浩
MA Zhaowei;LIU Jia;FU Zhanbo;LEI Xiaowei;GAO Qi;CUI Yongjie;ZHANG Yunhao(Luoyang Ship Material Research Institute,Luoyang 471300,China)
出处
《热加工工艺》
北大核心
2021年第19期35-38,共4页
Hot Working Technology
关键词
钛合金厚板
激光焊
T型接头
硬度
thick titanium alloy plate
laser welding
T-joint
hardness
