热镀锌钢盐雾腐蚀行为及机理研究.

In this work, the corrosion process and corrosion mechanism of hot-dip gal vanized steel under different time periods were clarified through investigating the corrosion behavior of hot-dip gal vanized steel under neutral salt spray corrosion. The neutral salt spray accelerated test was simulated, and t he influence of different corrosion periods on the corrosion behavior of hot- dip galvanized steel were compared by weight loss method, SEM,XRD and Raman spectroscopy. The results showed that the corrosion rate of hot-dip galvanized steel gradually increased and finally became stable with the increase of corrosion period under 8 corrosion periods. In the process of corrosion, white and light yellow rust appeared on the surface at first. With the intensification of corrosion, maraud-red and black rust gradually appeared on the surface, and the corrosion layer gradually changed from relatively compact to fluffy, cracking and peeling. The main corrosion products are ZnCl2, Zn(OH)2, β-FeOOH, Fe3O4 and Fe2O3 • The 30-day corrosion process of hot-dip galvanized steel can be divided into three stages: the protection stage of galvanized layer, the damage stage of galvanized layer and the failure stage of galvanized layer. Among them,the corrosion rate is the highest in the damage stage of galvanized layer, and the corrosion products in this stage are mainly yellow rust (α-FeOOH) and reddish-brown rust (Fe203, Fe ( OH)3 ). The corrosion products are fluffy and cracked, providing a channel for the next step of corrosion. With the increase of corrosion period, the carbon steel substrate gradually exposed,at this time, the corrosion rate decreases and tends to be stable, the corrosion products are mainly red brown rust and black rust (Fe304),and the corrosion products are fluffy and easy to drop. [ABSTRACT FROM AUTHOR]