焊后热处理对TA15钛合金中厚板焊接接头弯曲性能的影响

Effect of post weld heat treatment on bending property of welded joints of TA15 titanium alloy plate

研究了不同退火制度对TA15钛合金板材焊接接头处弯曲性能的影响。通过显微组织分析,探究了焊接接头组织随加热温度和保温时间变化的转变过程,通过极限弯曲试验验证组织变化对焊接接头弯曲性能的影响,最终确定最佳退火工艺。结果表明,TA15钛合金板材焊接接头处为典型的柱状晶组织,针状α相沿不同方向分布,焊接接头塑性较差,弯曲性能较差。采用一般的焊后稳定化退火处理(750℃×90 min和750℃×120 min)可以起到消除焊接应力的作用,但焊接接头处组织性能没有明显改善,未能使弯曲性能得到有效提升。经850℃×120 min退火,炉冷处理后,焊接接头组织得到明显改善,同时弯曲性能得到提升。

Effect of different annealing processes on the bending property of the welded joint of TA15 titanium alloy plate was studied.Through microstructure analysis,the microstructure transformation process of the welded joint with the change of heating temperature and holding time was explored.The effect of microstructure change on the bending property of welded joints through ultimate bending tests was verified,and ultimately the optimal annealing process was determined.The results indicate that the welded joint of the TA15 titanium alloy plate exhibits a typical columnar grain structure with needle⁃likeαphases are distributed in different directions,and the welded joint has poor plasticity and poor bending property.Using general post weld stabilization annealing treatment(750℃×90 min and 750℃×120 min)can alleviate the welding stress,but with no significant improvement in microstructure and properties of the welded joint,which fails to effectively enhance the bending property.After annealing at 850℃for 120 min with furnace cooling,the microstructure of welded joint is significantly improved,and at the same time,the bending property is improved.