Mechanism of Hydrogen Content on the Selective Oxidation of 1.49 Si-1.55 Mn High Strength QP Steel

The galvanizing experiment of QP steel was carried out in two different concentrations of hydrogen content (5% and 15%) with the aim of revealing the mechanism of different hydrogen content on the selective oxidation of high strength QP steel. The morphology of oxide and inhibitory layer on the surface of steel plate was observed by SEM, and the distribution of alloying elements on the surface and coating was characterized by GDOES. The results show that higher hydrogen content makes the environment more reductive, changing the iron oxide on the surface into active iron that can react with liquid zinc. As a result, the enrichment of Si and Mn on the surface is generally reduced, the compactness of the inhibition layer is reduced, the exposed area of the steel plate surface becomes larger, and the amount of leakage decreases.