等离子堆焊Q235电解打壳锤头的组织和性能

采用等离子堆焊技术在Q235铝电解打壳锤头表面堆焊F40合金粉末熔覆层。利用扫描电镜、能谱仪和显微硬度计等分析等离子堆焊层的微观组织、微区成分和硬度分布。利用磨擦磨损仪对试样进行耐磨性测试,通过恒电位法评估堆焊层和基体的耐蚀性能。结果表明,堆焊层与基体形成了良好的冶金结合,堆焊层为典型的柱状晶组织。等离子堆焊层平均显微硬度为444HV0.1,为基体的2倍;耐磨性为基体的1.6倍;腐蚀速率Rcorr为3.524×10-4 mm/a,为基体的1/(4.2×104)。等离子堆焊后Q235钢材料的耐磨性、硬度和耐腐蚀性均有显著提高,有望提高电解铝打壳锤头的耐磨耐蚀性能。

Microstructure and Properties of Plasma Arc Surfacing Layer on Q235 Crust Breaker for Aluminum Electrolysis Cell

The F40 alloy powder was deposited on the surface of Q235 crust breaker for aluminum electrolysis cell through plasma arc surfacing. The microstructure, composition and microhardness distribution of the plasma arc surfacing layer were investigated by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and microhardness system. The wear resistance and corrosion resistance of prepared samples were evaluated by the frictionwear test machine and constant potential rectifier. The results show that the plasma arc surfacing layer with typical column crystal structure and the matrix metal are obtained well with metallurgical bonding. The average microhardness of the layer was 444 HV_0.1, about twice than that of the matrix. The wear resistance of the layer was increased by 1.6 times as large as that of the matrix. The corrosion rate (R_corr) was 3.524×10^-4 mm/a, about 4.189×104 times less than that of the matrix. The hardness, wear resistance and corrosion resistance of the material are obviously improved by plasma arc surfacing, and the new material may meet the requirements of the crust breaker for aluminum electrolysis cell.