激光熔覆35.8%Fe-20%Ti-20%Al-24%Cr-0.2%Y_(2)O_(3)涂层组织与性能研究

Microstructure and Properties of 35.8%Fe-20%Ti-20%Al-24%Cr0.2%Y_(2)O_(3) Coatings Prepared by Laser Cladding

采用激光熔覆工艺在304不锈钢板表面制备质量分数35.8%Fe-20%Ti-20%Al-24%Cr-0.2%Y_(2)O_(3)的合金涂层,并对涂层的组织、元素分布和力学性能等进行了表征。结果表明:激光功率2200 W、扫描速率5 mm/s、搭接率50%条件下,获得的一次成型涂层,其组织均匀致密,无裂纹、气孔等缺陷;涂层与基体间为冶金结合,稀释率为7.31%;涂层相组成为(Fe,Cr)Al、Y_(2)TiO_(7)和TiO_(2),晶粒平均尺寸为6.7μm;涂层具有较高的硬度和良好的高温耐磨性能,硬度达到550 HV(基体为210 HV),400℃条件下磨损试验质量损失率仅为304不锈钢的3.67%。

The alloy coating with mass fraction of 35.8%Fe20%Ti20%Al_(2)4%Cr0.2%Y_(2)O_(3) was fabricated on the surface of 304 stainless steel by laser cladding process.The microstructures,elemental distributions,and mechanical properties of the coating were characterized.The results show that under the conditions of laser power of 2200 W,scanning velocity of 5 mm/s,and overlapping rate of 50%,the obtained coating has a uniform and dense structure without defects such as cracks and pores.There is a metallurgical bond between the coating and the substrate,and the dilution rate is 7.31%.Phase compositions of the coating are mainly(Fe,Cr)Al,Y_(2)TiO_(7),and TiO_(2).The average grain size is less than 6.7μm.As a result,the coating has high hardness and good high temperature wear resistance,the hardness reaches 550 HV(the substrate is 210 HV).The mass loss rate of wear test at 400℃is only 3.67%of that of 304 stainless steel.