| 摘要 |
PURPOSE:To produce an Al alloy hot dipped steel plate having excellent plating appearance, corrosion resistance and high-temp. durability by forming an underlying plating layer of Ni or Co alone or in combination thereof on the surface of a steel plate then carrying out Al hot dipping thereon. CONSTITUTION:After the surface of a cold rolled steel plate is cleaned by defatting, pickling and washing, an underlying plating layer of Ni or Co or an Ni-Co alloy is formed thereon at 0.05-1.0mu thickness. After washing and drying, the steel plate is preheated at about 450 deg.C and in succession the preheated steel plate is reduced and annealed at 780 deg.C in a furnace contg. gaseous atmosphere of a 15% H2-85% N2 compsn. The annealed steel plate is dipped in a Al hot dipping bath, an Al-8% Si plating bath or an Al-5% Si-1.5% Mg plating bath. There are no surface defects such as pinholes, unplating or the like, and the Al alloy hot dipped steel plate having excellent plating appearance, corrosion resistance and high-temp. durability is obtained. |
