Corrosion resistance, solder strength and spot weldability in excellent Sn-Zn melt-plated steel sheet and method of manufacturing the same

摘要

PROBLEM TO BE SOLVED: To provide a hot-dip Sn-Zn plated steel sheet excellent in soldering strength (strength after soldering), spot weldability and corrosion resistance, and to provide a method for production thereof.;SOLUTION: The Fe-Ni-Zn pre-plating by a composition comprising, by mass, 20-70% Ni, 0.05-5% Zn and the balance Fe with inevitable impurities is performed on a steel sheet in 0.2-2.0 g/m² as an Ni amount. Then, a hot-dip Sn-Zn plating is performed, and plating is coagulated in such a state that the Fe-Sn alloy layer having a particle size of ≤0.5 μm exists in 0.2-2.0 g/m² on the interface of plating/steel sheet. The obtained hot-dip Sn-Zn plated steel sheet has a coagulated composition inhibiting the segregation of Zn by which the corrosion resistance is degraded, and has excellent soldering strength (strength after soldering) and spot weldability.;COPYRIGHT: (C)2012,JPO&INPIT