K424镍基高温合金等离子束填丝熔覆修复开裂机理分析  

Cracking Mechanism of K424 Nickel-based High-temperature Alloy by Plasma Beam Wire-filling and Cladding Repair

作　　者：张传奎 刘奋成 秦礼彬 王鑫 刘丰刚 胡生双 余小斌 ZHANG Chuankui;LIU Fencheng;QIN Libin;WANG Xin;LIU Fenggang;HU Shengshuang;YU Xiaobin(National Defense Key Discipline Experiment of Light Alloy Processing Science and Technology,Nanchang Hangkong University,Nanchang 330063,China;Guizhou Anii Aviation Investment Casting Co.,Ltd.,Guizhou Anshun 561000,China;Avic Xi’an Aircraft Industry Group Company Ltd.,Xi’an 710089,China)

机构地区：[1]南昌航空大学轻合金加工科学与技术国防重点学科实验室,南昌330063 [2]贵州安吉航空精密铸造有限责任公司,贵州安顺561000 [3]中航西安飞机工业集团股份有限公司,西安710089

出　　处：《精密成形工程》2024年第12期108-115,共8页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(52361010,52265053);中国航空科学基金(2023Z049056001,2022Z049056001);江西省重点研发计划(20223BBE51005,20232BBE50001)。

摘　　要：目的针对高Al、Ti含量K424镍基高温合金铸造缺陷难修复的问题,开展等离子束填丝熔覆修复工艺研究,并分析K424合金修复过程的开裂机理。方法利用等离子束填丝熔覆修复技术进行K424合金铸造缺陷修复。在熔覆速度为0.002 m/s的条件下,调整焊接电流为50、60、70、80 A,以及在熔覆速度为0.001 m/s的条件下,调节焊接电流为60 A和70 A进行修复实验,研究不同工艺参数对K424合金修复裂纹敏感性的影响,并对开裂机理进行分析。结果在熔覆速度为0.002 m/s与等离束电压不变的情况下,当工作电流为50 A时,电流较低,修复区域出现未熔合缺陷,随着电流的增加,修复区出现裂纹;当电流为80 A时,出现贯穿形裂纹,且裂纹宽度较大;当焊接电流不变时,随着熔覆速度从0.002 m/s变成0.001 m/s,修复区裂纹数量与长度明显增加。结论随着电流的增加,当熔覆速度变低时,增大了K424合金修复区开裂倾向;元素偏析以及低熔点γ-γʹ共晶相的形成是造成修复过程中修复区域开裂的主要原因。The work aims to conduct in-depth research on the plasma beam wire-filling and cladding repair technique for addressing casting defects in K424 nickel-based high-temperature alloy with high Al and Ti content and analyze the cracking mechanisms involved in the repair process of the K424 alloy.The casting defects in the K424 alloy were repaired using the advanced plasma beam wire-fill cladding technique.Experiments were conducted under two distinct melting speeds:0.002 m/s and 0.001 m/s.At the melting speed of 0.002 m/s,the welding current was varied between 50,60,70,80 A.Similarly,at the melting speed of 0.001 m/s,the welding current was adjusted to 60 A and 70 A.These variations were implemented to investigate the impact of different process parameters on the crack sensitivity of the K424 alloy repairs and to dissect the cracking mechanism.The findings revealed that,at a constant isobaric beam voltage and a melting speed of 0.002 m/s,a welding current of 50 A resulted in insufficient heat input,leading to unfused defects within the repair area.As the current increased,cracks began to appear in the repaired area.Notably,when the current reached 80 A,penetration-shaped cracks emerged,characterized by substantial width.Furthermore,when the melting speed was reduced from 0.002 m/s to 0.001 m/s at constant welding current,a marked increase in the number and length of cracks within the repair area was observed.In conclusion,as the welding current increases,the propensity for cracking within the repaired zone of the K424 alloy intensifies,particularly when the cladding speed is lowered.The primary reasons for alloy cracking are the elemental segregation and the formation of a low-melting-pointγ-γʹeutectic phase.

关 键 词：等离子束修复 填丝 K424合金 开裂机理 

分 类 号：TG132.32[一般工业技术—材料科学与工程]