横向交流脉冲磁场对堆焊金属组织及性能的影响

Influence of transverse alternative magnetic field on microstructure and properties of plasma arc surfacing layer

通过在低碳钢表面进行等离子弧堆焊时外加交流脉冲横向磁场,研究了交流脉冲磁场对镍基自熔合金组织及性能的影响,并利用光学金相、X射线衍射、显微硬度和湿砂橡胶轮磨损试验等方法,系统分析了不同脉冲磁场电流、占空比作用下的堆焊试样的硬度、耐磨性及组织.结果表明,外加横向交流脉冲磁场可以有效改善堆焊层金属的结晶形态,细化晶粒,在适当的脉冲磁场电流、占空比作用下,可以获得最佳的电磁搅拌效果,增加堆焊层金属中硬质相的数量,控制硬质相的生长方向,提高等离子弧堆焊层的硬度和耐磨性.

In the research of the influence of alternative pulsed magnetic field on microstructure and properties of nickel-base alloy, a transverse alternative pulsed magnetic field had been applied to the plasma arc surfacing welding on low carbon steel. The hardness, wear resistance and microstructure of surfacing layer with different pulsed magnetic field currents, duty cycles have been systematically analyzed. The results indicated that transverse alternative pulsed magnetic field can effectively improve the crystal shape of plasma arc surfacing layer, refine crystal grain. Proper pulsed magnetic field current, duty cycle can obtain the optimum effect on electromagnetic stirring, which can increase the amount of hardening phase in overlay deposit, control the growth direction of hardening phase and improve the hardness and wear resistance of the surfacing overlay.