球墨铸铁表面激光熔覆C276涂层孔隙率优化及显微组织分析  

Optimization of Porosity and Microstructure Analysis in Laser-clad C276 Coating on Ductile Iron Surface

作　　者：张浩[1] 李大胜 ZHANG Hao;LI Dasheng(College of Intlligent Manufacturing,Anhui Science and Technology University,Chuzhou 233100,China;School of Mechanical and Vehicle Engineering,Bengbu University,Bengbu 233030,China)

机构地区：[1]安徽科技学院智能制造学院,安徽滁州239000 [2]蚌埠学院机械与车辆工程学院,安徽蚌埠233000

出　　处：《安阳工学院学报》2025年第2期53-58,66,共7页Journal of Anyang Institute of Technology

基　　金：安徽省高校自然科学重点科研项目(2022AH051911)。

摘　　要：为提高球墨铸铁表面的耐腐蚀性能,采用激光熔覆技术在球墨铸铁表面制备C276耐腐蚀涂层。利用金相显微镜观察宏观截面形貌;采用Box-Behnken设计单因素试验,研究孔隙率与工艺参数的变化关系;采用对比试验,探究不同光源对孔隙率的影响;利用腐蚀液腐蚀,研究涂层的显微组织结构。结果表明:确定扫描速率V_(t),的范围相对于激光功率P和送粉速率V_(s)具有更高的优先级。高斯光源可以有效降低搭接区域基材的热输入,从而消除搭接处孔隙富集现象,参数A的涂层平均孔隙率从0.08%降低为0.023%,参数B从0.123%降低为0.017%。初定扫描速率、后定激光功率和送粉速率、最后微调扫描速率,是孔隙率优化的可行方法,最佳P、V_(s)、V_(1)组合为1000W、10mm/s、0.6r/min和1300W、10mm/s、0.8r/min,截面平均孔隙率分别为0.023%、0.017%,涂层平均厚度分别为0.5mm、1.2mm。涂层晶粒依次由平面晶、胞状晶、柱状晶、等轴晶组成,连续、片状的白口组织被抑制,涂层整体晶粒细小,顶部大量的细化等轴晶粒提高了涂层的耐腐蚀性能。To improve the corrosion resistance of ductile iron surface,a C276 coating was prepared on the surface of ductile iron by laser cladding technology.Macroscopic cross-sectional morphology was observed by using a metallurgical microscope.Using Box-Behnken design and single factor experiments,the relationship between porosity and process parameters was studied.Through comparative experiments,the influence of different types of laser sources on the porosity of coatings was explored.The microstructure of coating cross-section was studied by using corosive solution for corrosion.The results indicate that determining the range of scanning speed V_(s),has a higher priority compared to laser power P and powder feeding rate V_(t).Gaussian laser source can effectively reduce the heat input of the substrate in the overlapping area,thereby suppressing the generation of pores at the overlapping area and eliminating the phenomenon of pore enrichment.The average porosity of the coating with parameter A decreased from 0.08%to 0.023%,and that of the coating with parameter B decreased from 0.123%to 0.017%.Initial determination of the scanning speed,followed by determination of the laser power and powder feeding rate,and finally fine adjustment of the scanning speed are feasible methods for optimizing the porosity of laser cladding coatings on the surface of ductile iron.The optimal solutions of parameters P、V_(s)、V_(1) obtained from optimization are 1000 W,10 mm/s,0.6 r/min and 1300 W,10 mm/s,0.8 r/min.The average porosity of the cross-section is 0.023% and 0.017%,respectively,and the average coating thickness is 0.5 mm and 1.2 mm,respectively.The coating grains are composed of planar grains,cellular grains,columnar grains,and equiaxed grains in sequence.The continuous and sheet-like white microstructure is suppressed,and the overall grain size of the coating is small.The large number of refined equiaxed grains at the top improves the corrosion resistance of the coating.

关 键 词：球墨铸铁 激光熔覆 C276 孔隙率优化 参数优化 高斯光束 

分 类 号：TG174.4[金属学及工艺—金属表面处理]