| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot-dip galvanized steel sheet superior in spot weldability, paintability and processability, and to provide a manufacturing method therefor. SOLUTION: The hot-dip galvanized steel sheet superior in the spot weldability, paintability and processability has a Zn-plated layer containing Ni and Al formed on a steel sheet through an Ni-Al-Zn-Fe alloy layer. The method for manufacturing the hot-dip galvanized steel sheet which has the above plated structure and is superior in the spot weldability, paintability and processability comprises the steps of: cleaning the surface of a steel sheet; forming a pre-plated film of Ni with a coating weight of 0.05 to 0.5 g/m<SP>2</SP>; rapidly heating the plated steel sheet to a sheet temperature of 430 to 500°C at a heating rate of 30°C/sec in a non-oxidative or reducing atmosphere; and hot-dipping it in a Zn plating bath containing 0.1 to 0.2 mass% Al and 0.001 to 0.05 mass% Ni. COPYRIGHT: (C)2007,JPO&INPIT
|
