TA18钛合金管材残余应力分析

Analysis of the Residual Stress in TA18 Titanium Tubes

本文利用X射线残余应力测试技术,对两种不同规格的TA18冷轧工艺制备钛合金管材内外表面残余应力进行测试,对比管材纵剖前后尺寸变化及不同方向残余应力释放比例,分析纵剖加工后局部残余应力和整体管结构约束残余应力的比例及变化规律,发现管材在纵剖后,切向上局部残余应力和更多约束残余应力的解除,即整体残余应力变化更大。因此测试残余应力时不应对管材进行整体纵剖,冷加工成型管材强化组织结构应尽量保留,但引入的残余应力却会对后续加工及应用产生不利影响。最后通过分析冷轧工艺中截面形状变化指数Q与两种残余应力的关系,确定合适的TA18钛管加工轧制成型工艺。

By using X ray residual stress measurement technology,the two kinds of different specifications of cold rolling process TA18 titanium alloy pipe inside and outside surface residual stress test in this paper,compare the size change before and after longitudinal profile and the proportion of residual stress release in different directions,analyze the proportion and variation law of local residual stress and constraint residual stress of whole pipe structure after longitudinal profile.It is found that the local residual stress and more restricted residual stress in tangential direction are relieved after the longitudinal section of the pipe,that is the overall residual stress changes more.Therefore,the Longitudinal section should not be carried out when testing the residual stress,and the strengthening structure should be retained as far as possible,but the residual stress will have a negative impact on the subsequent processing and application.Finally,by analyzing the relationship between section shape change index Q and two kinds of residual stresses in cold rolling process,the suitable rolling forming process of TA18 titanium tube was determined.