Zn—5%Al—RE合金镀浴对低碳钢板的溶解腐蚀

CORROSION OF LOW CARBON STEEL (AY1) IN Zn—5%Al—RE ALLOY BATH

本工作研究了热浸镀 Zn-5%Al-RE 合金过程中低碳钢板(AY 1)的溶解腐蚀。结果表明 I在490℃以上,腐蚀非常严重。合金层的生长动力学可分为两个阶段,第二阶段中合金层的持续剥落及溶解导致了铜板的严重腐蚀。RE 元素缩短了第一阶段合金层出现的孕育期,但对其生长动力学基本无影响,表明 RE 可能提高了 Zn-Al 共晶合金对钢板的润湿性,Al 则使第一阶段反应激活能提高,对钢板和合金的反应起到阻滞的作用。

A study on the dissolution of low carbon steel(AY 1,0.09C:0.37Mn; 0.22Si;0.018P;0.017S)in Zn-5%Al-RE(where RE stand for rare earth) alloy bath is carried out.The results demonstrate that severe corrosion occurswhen the dipping temperature is above 490℃(for 10min).The growth kinetics of the alloying layer can be divided int two stages,The continuod spalling-dissolving of the alloying layer at the second stage is thought to be the main cause of the serious corrosion of the steel. The incubation period of the alloying layer at the first stage is shortened by adding RE,but RE has no effects on the growth kinetics.This may suggest that RE has an ability to increase the wettability of Zn Al eutectic alloy with the low carbon steel.The apparent activation energy increases with an increasing amount of A1 in the bath,this reveals the inhibiting effect of A1.