Hot-dip galvanizing method for silicon-manganese high strength steel

• Main Authors: TU, RUI-FAN, YANG, GUO-ZHENG, CAI, MING-QIN, ZHANG, LIU-WEN, WANG, GUANG-GUO, XU, QIONG-WEN, JIANG, LONG-REN
• Format: Patent
• Language: Chinese; English
• Published: 01.10.2015
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

The present invention relates to a hot-dip galvanizing method for silicon-manganese high strength steel, the method comprising the steps of: (a) providing a steel material containing silicon and manganese; (b) at the dew point temperature, subjecting the steel material to an annealing step so as to form a ternary silicon-manganese oxide on the steel material surface; (c) after the annealing step, immersing the steel material in an aluminum-containing zinc bath for galvanizing, thus making the ternary silicon-manganese oxide on the steel material surface reduced to form an Fe-Al layer, wherein the coverage rate of the Fe-Al layer is greater than 70%; and (d) taking out the galvanized steel, and removing the excess liquid zinc on the steel material. In this way, it is possible to improve the galvanizing susceptibility of steel and reduce defects generation of uncoated dots.