High temperature nickel base alloy has good resistance to high temperature corrosion,high temperature wear and high temperature strength,and is used as surfacing material for diesel engine gas valve sealing surface.However,the surfacing quality of the sealing surface alloy layer cannot pass the thermal shock detection effectively,and the alloy will crack after thermal shock,which affects the application and promotion of the product.Based on this,this paper studies the effect of surfacing wire speed on thermal shock permeability of alloy.Plasma surfacing technology is used to prepare three groups of Colmonoy56 SPL powder alloy surfacing layers on 45Cr9Si3 gas valves at different welding wire speeds.Then the microstructure and Rockwell hardness of the alloy layer were analyzed by means of metallographic observation and hardness test.The experimental results show that the parameters of nickel-based superalloy surfacing welding are narrow,and the linear velocity is the main variable affecting the crack resistance of the alloy layer.For the test valve,the surfacing speed of 70 mm·min-1 can effectively solve the application problem of alloy cracking after thermal shock,so that the product can meet the requirements of thermal shock detection.
关键词
等离子堆焊/焊接线速度/高温镍基合金/热冲击性能
Key words
plasma surfacing welding/welding line speed/high temperature nickel-based alloy/thermal shock performance
维普
万方数据