摘要
目的探究激光除锈过程中激光对Q345钢金属基底表面残余应力和腐蚀性能的影响。方法采用扫描电子显微镜(SEM)和能谱仪(EDS)分析激光除锈试样表面形貌和氧元素含量,采用金相显微镜观察激光除锈后试样横截面的热影响层。采用背散射电子衍射仪(EBSD)和X射线衍射仪定性和定量地表征激光除锈后金属基底表面的残余应力。采用动电位极化曲线和零电阻安培法(ZRA)表征原始试样和激光除锈后试样表面的抗腐蚀性能。结果在激光除锈Q345钢过程中,基于激光局部热处理的原因,金属基底表面产生了100~150 MPa的残余拉应力。同时,在激光与金属基底的作用下,金属基底近表面形成了一层厚度约为25μm的热影响层,热影响层中的渗碳体和铁素体形成的微电池含量减少,渗碳体含量与铁素体含量的比值增大,使得自腐蚀电位增至−490 mV,腐蚀电流密度减至17μA/cm^(2)。结论在激光除锈过程中激光与金属基底的作用下,金属基底表面产生了残余拉应力,近表面形成了一层厚度约为25μm的热影响层,在二者的综合作用下提高了激光除锈后试样表面的抗腐蚀性能,延长了其使用寿命。
Laser derusting technology is an advanced surface treatment technology and due to its high cleaning degree,good control,green environmental protection and other advantages,it is widely used,especially in the rust and paint removal industry.However,in the process of laser derusting,in addition to the interaction between laser and surface contaminants,laser will also interact with the sample substrate,which will affect the microstructure,crystal structure and surface properties of the near surface of the sample substrate.Only by exploring the effect law of laser on the near surface of the sample,the laser cleaning technology can be better applied to the engineering field.In the process of laser derusting,residual stress is likely to occur near the surface of metal substrate due to local laser heat treatment.The existence of residual stress near the surface not only affects the surface mechanical properties,but more importantly,it may accelerate the corrosion rate of the metal substrate,reduce the corrosion resistance of the metal substrate,and affect the service life of the component.Therefore,in the process of laser derusting,whether the near surface of the metal substrate will produce residual stress,what type of residual stress will be generated,and what kind of change occurs in the corrosion resistance of the metal substrate surface are all crucial.The corrosion on the surface of Q345 steel is mainly composed of a mixture of Fe oxides and their hydrates,so the content of oxygen elements on the surface of the sample can effectively characterize the effect of laser derusting.Scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)were used to analyze the surface morphology and oxygen content of laser derusting samples.The results of EDS showed that there was no oxygen content on the surface of metal substrate after laser derusting.According to the cleaning effect and surface topography,the optimal parameters of laser derusting were determined as laser power 16 W,laser repetition rate 70 kHz and la
作者
任志国
王烁
王振兴
郝军
梁建明
REN Zhiguo;WANG Shuo;WANG Zhenxing;HAO Jun;LIANG Jianming(School of Mechanical Engineering,Hebei University of Architecture,Hebei Zhangjiakou 075000,China;Central Iron and Steel Research Institute,Beijing 100081,China;Zhonglong Electromechanical(Zhuolu)Company,Hebei Zhangjiakou 075000,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2024年第19期164-172,共9页
Surface Technology
基金
河北省高校基本科研业务费项目(2024QNJS012)
河北省高等学校科学技术研究项目(ZD2020201)
张家口市重点研发计划(2221230H)。
关键词
激光除锈
Q345钢
残余应力
腐蚀性能
表面处理
laser derusting
Q345 steel
residual stress
corrosion performance
surface treatment
