| 摘要 |
<p>A method of surface treatment of aluminum-killed and low alloy steel strip and sheet containing an alloying metal in an amount greater than the critical content thereof, for fluxless hot dip metallic coating, which comprises heating the steel in a furnace containing gaseous combustion products including from 5 to 1600 grains of sulfur per 100 cubic feet and up to about 6% free oxygen or up to about 7% by volume excess combustibles, whereby to form a sulfur and oxygen rich film on the steel surfaces, passing the steel into a further heating section wherein it is brought to a maximum temperature of 927.degree.C, passing the steel into a cooling section having an atmosphere containing at least 10% hydrogen and balance nitrogen whereby to reduce the sulfur and oxygen rich film, and cooling the steel approximately to the temperature of the molten coating metal bath. Coke oven gas may be used as the fuel for the furnace.</p> |
