摘要
在不同热输入条件下对3 mm厚TC4钛合金进行TIG焊接,焊后接头表面呈银白色且无外观缺陷。利用光学显微镜观察分析了焊接接头各区的组织变化规律,并划分了焊接接头区域,进一步对断口处晶粒大小、针状马氏体α'相尺寸进行测定,研究了它们与抗拉强度之间的关系。结果表明:接头细晶区与粗晶区之间晶粒尺寸具有突变趋势;随着晶粒尺寸的增加,焊接接头抗拉强度在逐渐降低;针状马氏体α'相尺寸长短对抗拉强度的影响不明显,其强化作用更倾向于马氏体α'相的编织效果和单向集束形态;细化晶粒对焊接接头的强化效果要优于马氏体α'相本身的强化作用。
TIG welding experiments of 3 mm thick TC4 titanium alloy were carried out by varying heat inputs. After welding,the surface of joints presented a silvery white color and a good appearance. By using optical microscope to observe the microstructure of weld metal,welded joint was divided into several pieces and variation law of microstructure was analyzed. The results show that there is a trend of sudden changein heat affected zone between fine grain zone and coarse grain zone. The tensile strength of joint decreases initially with the grain growth. Knitting efficacy and numbers of one-way cluster have great effect on tensile strength,but the length of needle martensite has few influence on the tensile strength of the joint. The strengthening effect of refining grain is remarkable than that of martensite α' phase' reinforcement.
出处
《焊接》
北大核心
2016年第7期27-31,69-70,共5页
Welding & Joining
基金
国家科学自然基金项目(51165027)
关键词
钛合金
TIG焊
晶粒
马氏体
抗拉强度
titanium alloys
TIG welding
grain size
martensite
tensile strength
