合金化蒸着亜鉛めっき鋼板のめっき層中のFe含有量と加工性

抄録

The drawability of zinc vapor deposited and galvannealed steel sheet, and the powdering behavior of the deposited layer during drawing were investigated. Heat treatment to form an alloy layer may be conducted either at higher temperatures (450-550°C) for short periods or at lower temperatures (280-340°C) for longer periods. The iron content of the deposited layer varied with heat treatment conditions from 9 to 15wt. %. When the ζ phase remains in the surface layer of the deposit, the degree of powdering decreases and drawability declines, but when the phase disappears, the layer peels easily and drawability improves. This may result from a decrease in the friction coefficient during drawing due to peeled powders. The ζ phase tends to remain in the deposited layer, when treatment is at lower temperatures, and little powdering occurs in these cases even though the iron content of the deposited layer is much higher than in the other cases.