Si含量对激光熔覆316L工艺及腐蚀性能的影响  

Effect of Si Element Content on the Manufacturing Process and Corrosion Performance of Laser Clad 316L

作　　者：董刚 尤涵潇 毛凯军 袁能军 戈民杰 俞学振 张群莉 姚建华 DONG Gang;YOU Hanxiao;MAO Kaijun;YUAN Nengjun;GE Minjie;YU Xuezhen;ZHANG Qunli;YAO Jianhua(Institute of Laser Advanced Manufacturing,Zhejiang University of Technology,Hangzhou 310023,China;College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,China;Collaborative Innovation Center of High-end Laser Manufacturing Equipment,Hangzhou 310023,China;Zhejiang Dongbin Rubber Plastic Co.,Ltd.,Zhejiang Zhoushan 316000,China)

机构地区：[1]浙江工业大学激光先进制造研究院,杭州310023 [2]浙江工业大学机械工程学院,杭州310023 [3]高端激光制造装备协同创新中心,杭州310023 [4]浙江栋斌橡塑螺杆有限公司,浙江舟山316000

出　　处：《表面技术》2024年第3期179-190,共12页Surface Technology

基　　金：浙江省“领雁”研发攻关计划项目(2022C01117);国家自然科学基金(52035014);浙江省公益技术应用研究项目(LGG20E050019);舟山市“揭榜挂帅”科技攻关项目(2022C01019)。

摘　　要：目的提高316L不锈钢粉末中Si元素的含量来改变熔覆层的组织形貌,进而提高熔覆层的耐腐蚀性能。方法采用激光共聚焦显微镜、扫描电镜、X射线衍射仪、差重-热差测试对熔覆层试样的宏观形貌与微观结构组成进行表征。结果随着Si含量的提升,激光熔覆层厚度增大,平均单层熔覆层厚度由0.8%Si的700μm熔高增大至1.2%Si的800μm与1.6%Si的900μm,分别增大了14%与29%。其次,Si含量的提升能显著提升熔覆层的抗高温氧化性能,高温下氧化形成的SiO_(2)膜层能够有效阻碍O_(2)对熔池的氧化。TG测试结果表明,0.8%Si在高温下的平均氧化质量增量为32%,而1.6%Si的氧化质量增量仅为19%。同时,原位生成的纳米氧化硅颗粒使得熔覆层组织晶粒出现细化。最后,随着Si元素含量的提升,熔覆层的耐腐蚀性能得到显著提升。Si元素形成的氧化膜层能有效阻碍腐蚀的进行,提升熔覆层的腐蚀性能。熔覆层自腐蚀电位正向偏移,腐蚀电流下降,同时熔覆层阻值提升。结论随着Si元素的质量分数由0.8%提升至1.6%,熔覆层的工艺性能显著提升,熔覆层厚度增加,且高温抗氧化性能提升,同时熔覆层的耐腐蚀性能得到显著提高。As research into metal additive manufacturing continues,laser cladding is gaining increasing attention in the forming and reworking of complex parts.The heating rate and cooling rate in laser processing are extremely high,which can lead to cracks and damage to the cladding layer.The risk of cracking is reduced by increasing the Si content of the laser cladding powder.This lowers the melting point of the powder,thereby reducing the heat input during processing.However,the effect of Si is not limited to lowering the melting point of the powder.In order to investigate the effect of Si on the fabrication process and the corrosion performance of cladding layers,316L cladding layers with different Si contents were fabricated on 316L substrates with 0.8%Si-316L,1.2%Si-316L and 1.6%Si-316L powders,respectively.The macroscopic morphology and microstructural composition of the cladding samples were characterized by laser confocal microscopy,scanning electron microscopy,X-ray diffraction and thermogravimetric analysis.It was found that the thickness of the laser cladding layer increased as the Si content increased.The average thickness of a single layer increased from 700μm at 0.8%Si to 800μm at 1.2%Si and to 900μm at 1.6%Si,increasing by 14%and 29%.At the same time,because the laser cladding layers were stacked layer by layer,the entire layer underwent a complex thermal cycling process that greatly affected the stability of the final cladding properties.By increasing the Si content of the powder,the number of stacked layers could be reduced.This would result in a more consistent quality of the final layer.In the meantime,the oxidation of elemental Si produced SiO_(2),which protected the melt pool well and reduced the oxidation of the cladding layer.The results of the TG tests showed that 0.8%Si oxidized at high temperatures and gained an average of 32%by weight,whereas 1.6%Si oxidized at a rate of only 19%by weight.Si preferentially reacted with oxygen to protect the remaining elements in the melt pool for thermodynamic

关 键 词：激光熔覆 316 SI 工艺性能 腐蚀性能 

分 类 号：TG174[金属学及工艺—金属表面处理]