A method for strengthening the coating adhesion of 780mpa grade hot-dip galvanized dual-phase steel
By employing a three-stage heating and annealing process, pre-oxidation, hydrogen reduction, and post-plating cooling, combined with the use of rare earth elements, the problem of insufficient adhesion of the 780MPa grade hot-dip galvanized duplex steel coating was solved, achieving improved coating uniformity and corrosion resistance, thus meeting the performance requirements of high-end cars.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BENGANG STEEL PLATES CO LTD
- Filing Date
- 2026-05-08
- Publication Date
- 2026-06-05
AI Technical Summary
The existing 780MPa grade hot-dip galvanized duplex steel coating has problems such as insufficient coating adhesion, uneven structure, poor continuity of the inhibition layer, unstable corrosion resistance and rough surface, which affect the reliability of components and the safety of the whole vehicle.
The process employs a three-stage heating and annealing process, pre-oxidation, hydrogen reduction, and a two-stage cooling process, combined with post-plating cooling. By controlling the diffusion of Si and Mn elements and adding rare earth elements Nb and Y, corrosion resistance is improved. Furthermore, through microstructure regulation and pre-oxidation control technology, a continuous and dense inhibition layer is formed.
It improves the adhesion and uniformity of the coating, ensuring that the coating is not easily peeled off when bending or stamping, meets the requirements of tensile strength and elongation, and enhances the corrosion resistance and overall performance of the coating.
Smart Images
Figure CN122147218A_ABST