残余拉应力区宽度变大。 文中还给出了焊后热处理后的应力大小情况，以证明焊后热处理能改善应力分布。
The weld residual stress by PWTH is discussed in order to prove that PWTH can really improve the distribution of stress.
采用焊接热模拟的方法，模拟HAZ粗晶区组织，并在不同回火参数下对试样进行焊后热处理。
By use of the method of welding thermal simulation, the morphology in HAZ was simulated and the post-weld heat treatment under different tempering parameter to the test specimen was carried out.
经焊后回火热处理后，主要合金元素沿焊合区的扩散区宽度增大；焊合区钛合金侧硬度值显著提高。
The diffusion zone width of main alloying elements increases and hardness of the friction weld zone near TC4 titanium alloy side improves after post-weld heat treatment.
应用推荐