960高强钢脉冲TIG电弧增材制造热过程及组织与力学性能研究  

Study on Thermal Process,Microstructure and Mechanical Properties of Thin-walled Components During Pulsed TIG Wire Arc Additive Manufacturing of 960 High-strength Steel

作　　者：陆万全 乔及森[1,2] 王磊[1,2] 刘永涛[1,2] 冯睿 祝伟 LU Wanquan;QIAO Jisen;WANG Lei;LIU Yongtao;FENG Rui;ZHU Wei(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院,兰州730050 [2]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050

出　　处：《材料导报》2023年第14期103-109,共7页Materials Reports

基　　金：国家自然科学基金(52063017);有色金属先进加工与循环利用国家重点实验室联合资助项目(18LHPY007)。

摘　　要：采用直流和脉冲直流钨极惰性气体保护焊(Tungsten Inert Gas Welding,TIG焊)电弧沉积工艺来制造960高强钢薄壁构件。通过对比分析两种沉积方法,系统研究了不同工艺因素对沉积热过程中熔滴过渡和熔池稳定性的影响,探讨了沉积与结合层微观组织和力学性能的演化规律,为脉冲TIG(Pulsed-TIG)技术的工程应用提供有益参考。结果表明,直流TIG-WAAM(Wire arc additive manufacturing)和脉冲直流TIG-WAAM(Pulsed-TIG-WAAM)工艺下,构件整体成形过程相对稳定,脉冲直流沉积构件的焊道高宽比相对较低,加入脉冲后沉积层变得更为扁平,有利于沉积过程中熔池保持稳定,提高成形精度。沉积层自下而上的微观组织分布较不均匀,底层为细小奥氏体晶粒,中层为粗大等轴晶,顶层为奥氏体组织。脉冲的引入有效改善了组织均匀性,回火马氏体组织的形成提高了材料的塑性和韧性。直流TIG-WAAM和脉冲直流TIG-WAAM熔滴过渡模式分别为大滴过渡和细滴过渡,过渡频率分别为5.24 Hz和9.17 Hz。脉冲条件下的细滴过渡模式更有利于保证整个沉积过程的热稳定性、构件成形精度和工艺稳定性。We made a 3D printing of 960 high-strength steel thin-walled components using direct current and pulsed current wire arc additive manufactu-ring and conducted the research on thermal process,microstructure and mechanical properties of thin-walled components during wire arc additive manufacturing of 960 high-strength steel,which provides useful reference for the engineering application of Pulsed-TIG(PTIG)technology.The results indicated that both the direct current deposition and the pulsed current one are really stable,and have reliable precision.The height to width ratio of pulse current deposition component is relatively low and the deposition layer becomes more flatter after pulse is added,which is beneficial to keep the molten pool stable during deposition and improve the forming accuracy.The microstructure distribution of the sedimentary layer from bottom to top is not uniform.The bottom layer is composed of fine austenite grains,the middle layer is coarse equiaxed grains,and the top layer is composed of austenite and partially tempered martensite.Through the introduction of pulse,the structure uniformity and temper martensite structure formation are effectively improved,and the plasticity and toughness of the material are improved.Direct current TIG-wire arc additive manufacturing(TIG-WAAM)and pulse current TIG-wire arc additive manufacturing(PTIG-WAAM)droplet transition modes were large droplet transition and fine droplet transition,respectively,and the transition frequencies were 5.24 Hz and 9.17 Hz,respectively.The high-frequency transition mode of droplets under pulse current is more beneficial to ensure the thermal stability,forming accuracy and process stability of the whole deposition process.

关 键 词：脉冲TIG增材制造 960高强钢 宏观和微观结构 熔滴过渡 力学性能 

分 类 号：TG457[金属学及工艺—焊接]