Comparison Analysis of Galvannealed Bake-hardenable Steel Sheets Produced Domestically and Abroad

The characteristics of galvannealed bake-hardenable steel sheets produced domestically and abroad, such as substrate chemical compositions, mechanical properties, coating powdering amount, coating mass, coating iron content, coating aluminium content, coating main elements distribution, coating surface morphology, coating SEM brittle fracture morphology, coating XRD phase compositions and coating surface roughness, were compared and analyzed. The results indicate that the substrate chemical composition, coating mass control and the cooling rate of the steel after galvannealing should be improved to get better galvannealed bake-hardenable steel products with good strength, powdering resistance and other properties at home.