There are four basic factors that affect the strength and rational performance of welds:
1) The chemical composition of the weld metal determines the composition of the weld metal phase, and the chemical composition of the weld titanium tube depends on the following two factors: the system of weld metal alloying realized by filling the titanium tube; and The ratio of base metal and filler metal can be changed by different welding methods and groove forms.
2) The phase change when the welded titanium pipe is cooled, and the severe phase change occurs under repeated high temperature heating during multilayer welding.
3) Microstructure changes and phase transformations of alloyed weld metals in post-weld heat treatment (stabilized annealing or quenching and aging).
4) The effect of various defects, especially the effect of pores. It affects static load and low cycle fatigue performance. It is related to the unique "hydrogen" destruction mechanism of the weld metal of the studied a-10b titanium alloy
