Low-Si steel samples were coated with Zn-Al and Zn-Al-Mg layers (Mg content 3 or 6% by mass) by dipping at 450 degrees C and studied for corrosion resistance sep. under action of neutral salt spray and moist SO2-contg. atm. according to the resp. stds. The corrosion resistance of ZnAlMg coatings was higher than that of ZnAI coatings.