a coating of aluminum or an aluminum alloy sheet and its manufacturing method korrosionsgeschütztes

摘要

Corrosion-resistant sheet steel contg. 0.002-0.02 wt.% dissolved N2 is coated on at least one side with Al or an Al-alloy, esp. contg. Si. A barrier against Al and Fe diffusion is present between the Al or Al-alloy corrosion-resistant coating and the sheet steel. Mfr. of said coated sheet steel involves immersion of the steel in a bath of molten Al or Al-alloy (esp. contg. Si) following pretreatment, namely hot rolling, rapid cooling to 550-600 deg.C (resulting in min. 0.002 wt.% dissolved N2), cold rolling and finally surface purificn. by heating to 700-720 deg.C. ADVANTAGE - Mechanical deformation is possible following thermal stress at max. 500 deg.C without destruction of the protective coating.