脉冲电流对Inconel 625合金裂纹尖端组织及性能的影响  

Effect of electropulsing on microstructure and properties of Inconel 625 alloy crack tip

作　　者：邓德伟[1,2] 刘倩倩[1] 李晓娜[1] 于涛[3] 张林[2] 杨树华[2] 张洪潮[3] 

机构地区：[1]大连理工大学材料科学与工程学院辽宁省凝固控制与数字化制备技术重点实验室大连,辽宁大连116024 [2]沈阳鼓风机集团股份有限公司,辽宁沈阳110869 [3]大连理工大学机械工程学院,辽宁大连116024

出　　处：《金属热处理》2017年第3期52-56,共5页Heat Treatment of Metals

基　　金：国家重点基础研究发展计划(973计划)(2011CB013402);辽宁省自然科学基金(2014028002);辽宁省科技创新重大专项(201303002);辽宁省重大装备制造协同创新中心;沈鼓-大工重大科研发展基金;中央高校基本科研业务费专项资金

摘　　要：为了降低裂纹的扩展速率并提高其性能,利用高密度脉冲电流对带有预制单边裂纹的Inconel 625进行止裂处理。利用金相显微镜(OM)、透射电子显微镜(TEM)对脉冲电流处理前后裂纹尖端微观组织结构进行分析;利用维氏硬度计及拉伸试验机对脉冲电流处理前后试样的显微硬度、抗拉强度及伸长率进行测量。结果表明:脉冲电流处理后裂纹尖端组织由等轴晶转变为枝晶,且在枝晶前方有细小晶区出现,晶粒内部位错密度降低,位错平行排布向晶界处运动。经脉冲电流处理后,裂纹尖端的显微硬度少量增加,在不降低伸长率的同时,试件抗拉强度提升23.85%。For the purpose of reducing crack propagation rate and improving its performance,crack arrest of Inconel 625 with prefabricated unilateral crack was performed by high density electropulsing technology. The microstructure at the crack tip was analyzed by means of optical microscope（ OM） and transmission electron microscope（ TEM）. The microhardness,tensile strength and elongation of the sample were measured using the Vickers hardness tester and tensile testing machine. The results show that the microstructure at the crack tip turns into the columnar crystals from the isometric crystal,and the fine crystals area is observed in front of them. The dislocation density in grains decreases,and the dislocation with paralleled configuration move to the grain boundary. The microhardness of the crack tip is slightly increased after electropulsing treatment,and the tensile strength is enhanced by 23. 85% with the same elongation as before.

关 键 词：INCONEL 625合金 脉冲电流 裂纹止裂 显微组织 力学性能 

分 类 号：TG142.7[一般工业技术—材料科学与工程]