后处理对退火态TC4 ELI合金显微组织与性能的影响  

Effect of post heat treatment on the microstructure and properties of as-annealed TC4 ELI alloy

作　　者：尹艳超 孙志杰 薛达 锁永永 刘海彬 Yin Yanchao;Sun Zhijie;Xue Da;Suo Yongyong;Liu Haibin(Luoyang Ship Material Research Institute,Luoyang 471023,Henen,China)

机构地区：[1]中国船舶集团有限公司第七二五研究所,河南洛阳471023

出　　处：《钢铁钒钛》2024年第3期55-64,共10页Iron Steel Vanadium Titanium

基　　金：中国船舶七二五所科技创新项目(编号:LW230803)。

摘　　要：采用光学金相显微镜(OM)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、室温拉伸、夏比冲击试验研究了后处理工艺对退火态TC4 ELI合金显微组织和力学性能的影响。结果表明,退火态TC4 ELI合金经520~720℃时效处理后发生“双态→等轴”的逆转变现象,强度呈现先升高后降低的趋势;冲击功在560℃降至最低后随温度升高稍有提高;时效α相的出现是冲击韧性劣化的主要原因,α2相析出的影响则较小。620℃时效态TC4 ELI合金经高温处理后,强度略微升高;温度升至β相区时,组织粗化造成屈服强度突降,晶界α相的出现引起塑性突降;高温处理后,时效α相消失,冲击功得到较大程度的恢复。The effects of post heat treatment on the microstructure and mechanical properties of annealed TC4 ELI alloy investigated by optical microscopy(OM),transmission electron microscopy(TEM),scanning electron microscopy(SEM),tensile and Charpy impact test at room temperature.The results show that the"bimodal→equiaxed"reverse transformation occurs in the annealed TC4 ELI alloy after aging at 520-720℃,and the strength increases first and then decreases.The impact toughness of the annealed TC4 ELI alloy decreases to the lowest value at 560℃,then increases slightly with the increase of temperature.The appearance of agingαphase is the main reason for the deterioration of impact toughness,while the precipitation ofα2 phase has little effect.The strength of TC4 ELI alloy aged at 620℃increases slightly after high temperature treatment.When the temperature rises to theβphase region,the coarsening of the microstructure causes a sudden drop in yield strength,and the appearance of theαphase at the grain boundary causes a sudden drop in plasticity.After high temperature treatment,the agingαphase disappears,and the impact toughness is recovered to a greater extent.

关 键 词：退火态TC4 ELI合金 后处理 显微组织 强度 冲击韧性 

分 类 号：TF823[冶金工程—有色金属冶金] TG156[金属学及工艺—热处理]