The effect of hydrogen addition on compression deformation behaviour of Ti–0.3Mo–0.8Ni alloy argon-arc welded joint has been investigated. Evolution mechanism of hydrogen-induced flow stress was discussed in detail. The results show that with increasing hydrogen content, the stretching and bending extent of fully lamellar microstructures including α lamellas and acicular hydride continued to increase, the morphology of dynamic recrystallization (DRX) grains tended to change from approximately equiaxed to large lamellar shape, and the quantity of DRX grains and recrystallization degree of grains increased obviously. A large number of dislocations concentrated in the vicinity of the hydride. Steady stress was decreased continuously with increasing hydrogen content, while peak stress of the hydrogenated 0.12 wt.% H weld zone was decreased to the minimum value and then increased slowly. A slight decrease in flow stress of the hydrogenated 0.05 wt.% H weld zone was caused by limited increase in the volume fraction of softer β phase. Hydrogen-induced DRX of α phase and improved dislocation movement by strong interaction between the hydride and dislocation directly resulted in a sharp drop in flow stress of the hydrogenated 0.12 and 0.21 wt.% H weld zone. Solute hydrogen also finitely contributed to a sharp drop in flow stress of the hydrogenated 0.12 and 0.21 wt.% H weld zone by promoted local softening, which induced continuous DRX and more movable dislocations to participate in slipping or climbing. The reinforcement effect and plastic deformation of the hydride and solution strengthening of β phase induced by solute hydrogen finally led to the increase in flow stress of the hydrogenated 0.21 wt.% H weld zone in its true strain range from 0 to 0.36.

研究了添加氢对Ti–0.3Mo–0.8Ni合金氩弧焊接头压缩变形行为的影响。详细讨论了氢致流应力的演化机理。结果表明，随着氢含量的增加，包括α片层和针状氢化物在内的完全层状微结构的拉伸和弯曲程度持续增加，动态重结晶（DRX）晶粒的形态趋于从近似等轴向大的层状转变，并且DRX晶粒的数量和晶粒的再结晶度明显增加。大量的位错集中在氢化物附近。随着氢含量的增加，稳态应力​​不断降低，而氢化0.12 wt。％H焊接区减小到最小值，然后缓慢增加。氢化的0.05 wt。％H焊接区的流动应力略有下降是由于较软的β相体积分数的有限增加所致。氢诱导的α相DRX以及由于氢化物与位错之间的强相互作用而改善的位错运动直接导致氢化的0.12和0.21 wt。％H焊接区的流动应力急剧下降。溶质氢还通过促进局部软化而有限地促进了氢化的0.12和0.21 wt。％H焊接区的流动应力的急剧下降，这引起了连续的DRX和更多的可移动位错参与滑动或爬升。