激光喷丸强化IN718高温合金抗热腐蚀机理  

Mechanism of hot corrosion resistance of IN718 superalloy strengthened by laser peening

作　　者：陈松玲[1] 周建忠[1] 黄舒[1] 张慧春[2] CHEN Songling;ZHOU Jianzhong;HUANG Shu;ZHANG Huichun(School of Mechanical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China;College of Mechanical and Electronic Engineering,Nanjing Forestry University, Nanjing, Jiangsu 210037,China)

机构地区：[1]江苏大学机械工程学院,江苏镇江212013 [2]南京林业大学机械电子工程学院,江苏南京210037

出　　处：《排灌机械工程学报》2021年第10期1068-1074,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51775252,52005223);中国博士后科学基金资助项目(2018M630526);江苏省自然科学基金项目(BK20180881);江苏省第十五批“六大人才高峰”高层次人才选拔培养资助项目(GDZB-050);泰州市科技支撑计划产业关键技术研发项目(TG202026);江苏省普通高校研究生科研创新计划项目(CXLX13_639)。

摘　　要：为了研究激光喷丸对IN718高温合金抗热腐蚀性能的影响,首先对IN718高温合金进行高功率激光喷丸强化处理,随后将试样置于800℃环境中进行热腐蚀试验,分别对比了喷丸样和未喷丸样残余压应力、微观组织、热腐蚀动力学曲线、腐蚀层的表面形貌和截面形貌等热腐蚀特性,最后阐述了激光喷丸强化IN718高温合金抗热腐蚀的机理.研究结果表明,激光喷丸样表层产生残余压应力且晶粒发生细化,喷丸样热腐蚀速率明显低于未喷丸样,喷丸样的腐蚀裂纹和腐蚀坑洞减少.分析认为晶粒细化加快了试样表面保护性氧化膜形成速度,减小了氧化膜内热应力和生长应力,残余压应力提高了表层氧化膜的黏附性.同时,晶粒细化以及高温下晶界δ相的析出阻碍了硫、氧等元素的侵入,减缓了内硫化氧化速度,从而提高了IN718高温合金的抗热腐蚀性能.To study the effects of laser peening(LP)on the hot corrosion resistance properties of IN718 superalloy,samples were subjected by high-power LP treatments,and then the corrosion experiments were performed in hot environment of 800℃.The compressive residual stress,microstructure,hot corrosion kinetics curves,surface morphologies and cross-section morphologies of the corrosion layers of LPed and non-LPed samples were compared.Finally,the mechanism of hot corrosion resistance strengthened by LP was revealed.The results show that the compressive residual stress is generated and the grains are refined on the surface of LPed sample.While compared with non-LPed sample,the hot corrosion rate of LPed sample is significantly reduced and the number of the corrosion cracks and pits of LPed samples are decreased.The grain refinement speeds up the formation of protective oxide films on the surface of LPed samples,and reduces the thermal stress and growth stress in the oxide films.The compressive residual stress improves the adhesion of the surface oxide films.In addition,the grain refinement andδphase precipitating on grain boundaries at high temperature hinders the invasion of sulfur,oxygen and other elements,and slows down the internal sulfurization and oxidation rate.As a result,LP can improve the hot corrosion resistance of IN718 superalloy.

关 键 词：激光喷丸 IN718高温合金 微观结构 热腐蚀 

分 类 号：TN249[电子电信—物理电子学]