钛合金TB5板坯脆断原因分析

来源期刊：钢铁钒钛2011年第1期

论文作者：黄德明 杨雄飞 韦青峰 王怀柳 周茂华 陈鑫 赵同新 徐聪

文章页码：23 - 28

关键词：钛合金； TB5； 板坯； 断裂； 等轴晶

Key words：titanium alloy； TB5； slab； cleavage； equiaxed grains

摘    要：通过对发生脆性断裂的钛合金TB5试制板坯的化学成分、断口形貌、微观组织进行分析,结果表明板坯化学成分均匀,满足国标要求;断口呈解理及准解理断裂特征,断口有析出相存在,但无夹杂物出现;板坯组织为粗大的等轴晶,晶内有长针片状的析出相,分布均匀且规则。分析显示:板坯发生脆断行为与化学成分无关,导致板坯脆性断裂的原因是板坯晶粒粗大,同时晶粒内析出了粗大的析出相,割裂了β基体,阻碍变形时位错运动,严重降低了板坯的塑性。

Abstract: Chemical composition,fracture features and microstructure of TB5 slab were investigated.The results indicated that chemical compositions of slab are uniform and meet the national requirements.The fracture feature of slab was cleavage or quasi-cleavage.There were precipitated phases in the fracture,but no inclusions in it.The microstructure of slab was rough equiaxed grains,in which there are long needle-like precipitation phases,and the distribution of the phases are uniform.The analysis results showed that the slab fracture was not related to chemical composition but to the rough grains and the coarse precipitation phases existed in the grains,which cut the β-matrix apart and impeded dislocation movement,therefore reduced greatly plasticity of TB5 slab.