摘要
通过对300M钢表面激光熔覆316L不锈钢修复的实验研究,探究激光熔覆修复层的组织及性能,本文在前期实验的基础上,选用316L不锈钢粉末作为熔覆材料,开展变功率激光熔覆对比实验研究。采用金相分析、EDS分析、XRD分析、电化学分析的方法,研究了不同激光功率对熔覆层宏/微观组织、显微硬度和耐蚀性能的影响。结果表明:当激光功率为1.5 kW时,在300M钢基体上熔覆得到质量最优的316L不锈钢熔覆层;熔覆层与基体呈冶金结合,底部为平面晶组织,中下部是胞状晶/柱状晶,中上部是树枝晶/等轴晶,表层主要是等轴晶组织;激光功率为1.5 kW时,熔覆层硬度为基体硬度的2.5~3倍,更加适合具有摩擦及冲击的实际工况,且熔覆层腐蚀电位最低,为-462.65 mV,自腐蚀电流最小,为3.63×10^(-3) mA,因而其耐蚀性能最好;不同激光功率熔覆层的阻抗大小排序为:1.5 kW>2.0 kW>1.0 kW。
Through the experimental study of 316L stainless steel laser cladding repair on the surface of 300M steel,the structure and properties of the laser cladding repair layer were discussed.On the basis of previous experiments,this paper selected 316L stainless steel powder as cladding material to carry out variable power laser cladding comparative experimental research.By means of metallographic analysis,EDS analysis,XRD analysis and electrochemical analysis,the effects of different laser power on the microstructure,microhardness and corrosion resistance of the coating were analyzed.The results show that when the laser power is 1.5 kW,the coating quality is the best,and the cladding layer and the substrate are metallurgically bonded.The bottom of the cladding layer is planar crystal structure,the lower part of the cladding layer is cellular crystal and columnar crystal,and the upper part is dendrite and equiaxed crystal,the surface layer is mainly equiaxed crystal structure.When the laser power is 1.5 kW,the maximum hardness of the cladding layer is 2.5~3 times of the matrix hardness,which is more suitable for actual working conditions with friction and impact,additionally,the coating has the lowest corrosion potential(-462.65 mV)and the minimum self-corrosion current(3.63×10^(-3) mA),so its corrosion resistance is the best.The impedance of cladding coatings with different laser power was ranked as:1.5 kW>2.0 kW>1.0 kW.
作者
崔静
路梦柯
翟巍
张杭
杨广峰
CUI Jing;LU Meng-ke;ZHAI Wei;ZHANG Hang;YANG Guang-feng(College of the Airport,Civil Aviation University of China,Tianjin 300300,China)
出处
《激光与红外》
CAS
CSCD
北大核心
2021年第6期710-719,共10页
Laser & Infrared
基金
国家自然科学基金项目(No.U1633111)
中国民航大学蓝天青年学者培养经费资助。
