热浸镀铝球墨铸铁氩弧重熔工艺

为强化热浸镀铝层的耐磨性能,将球墨铸铁经780℃热浸镀铝后进行氩弧重熔处理,分析重熔工艺参数对重熔层性能的影响,利用扫描电镜对热浸镀铝层和氩弧重熔层组织进行了观察。结果表明:热浸镀铝层经氩弧重熔处理后,组织改善,由原来富铝层和扩散层转变为重熔层和过渡层。氩弧重熔工艺参数对重熔组织裂纹率、熔深、表面硬度影响较大,重熔电流增大或电弧扫描速度减小时,重熔层裂纹率下降,熔深增加,硬度升高。在重熔电流为70～120 A时,重熔层和过渡层硬度最高可达8.430和8.820 GPa。氩弧重熔处理能明显提高热浸镀铝层的显微硬度。

Argon arc remelting process of hot-dip aluminum ductile iron

This paper is aimed at strengthening the wear resistance of hot-dip aluminum coating by subjecting ductile iron to hot dip aluminum treatment with 780℃, followed by TIG remehing. The paper describes the effect of remehing process parameters on the performance of remehing layer and use of scan- ning electron microscopy to observe thermal dip aluminum coating and argon arc remelting layer. The re- sults show that hot-dip aluminized layer treated by argon arc remelting processing shows a structure im- provement from the Al-rich layer and the diffusion layer into the remelting layer and buffer layer. Argon arc remehing process parameters have a greater impact on the crack rate of remehing organization, pene- tration depth, and surface hardness. Increases in remelting current or decreases in arc scanning speed mean the decreases in remehing layer crack rate, and increases in the penetration depth and the hard- ness. With the remelting current of 70 to 120 A, remehing layer and transition layer have a greatest hard- ness up to 8. 430 and 8. 820 GPa. Argon arc remelting treatment allows a significant improvement in the microhardness of hot-dip aluminum coating.