Study Of The Materials With Corrosion Resistance To The High Temperature Molten Zinc

The corrosion of high temperature molten zinc to the container is a very serious problem. There are a lot of research on zinc smelting crucible material's corrosion. For example,in the temperature range 450℃～550℃, Fe-B and Fe-Al-B alloys show better corrosion resistance ability to molten zinc, the addition of Cr and Ni elements further improve corrosion resistance properties to molten zinc corrosion.Recently,the high temperature molten zinc corrosion was a serious problem in many field. For example, high purity zinc distillation, and zinc reduction method in the process of polysilicon production. One of the important problems is the temperature of molten zinc is very high, which reaches 900℃. Most of the studies focuses on the corrosion at the temperature 450℃～550℃,but the study on high temperaturecorrosion(>600℃) was rarely involved. So,the reduction process of zinc was restricted. Therefore, in this paper, corrosion behaviors on high temperature molten zinc were investigated.The permeability silicon SiC and iron-base alloy were selected,the corrosion experiments were carried out molten zinc in the 600℃～800℃. Using weight loss method, the corrosion rates were measured at different temperatures. The corrosion surface of SiC and iron-base alloy samples were observed by SEM and the corrosion mechanisms were discussed. Experimental results showed that the molten zinc corrosion of iron-base alloy was dominated by dissolvent corrosion. The corrosion rate of iron-base alloy is higher than that of SiC. The stainless steel dissolves at 700℃/8h,while it dissolves at 750℃/5h and 800℃/5h. For permeability silicon SiC,the molten zinc corrosion was cooperatively caused by the cracks, spalling, and dissolvent of Si. Corrosion rate of SiC was affected greatly by temperature. The corrosion rate of SiC was slight when the molten zinc temperature is lower than 750℃. The corrosion rate is only 0.6% at 750℃for 8 hours. However, the dissolvent corrosion of SiC was more obvious when the temperature was higher than 800℃, and the corrosion rate increases rapidly, which is up to 3% at 800℃for 8 hours.