PRODUCTION OF THINLY TINNED STEEL SHEET HAVING SUPERIOR RUST RESISTANCE AND WELDABILITY

摘要

PURPOSE:To produce a thinly tinned steel sheet having superior rust resistance and weldability at a low cost by successively tinning and galvanizing the surface of a cold rolled low carbon steel sheet under specified conditions and by alloying all of Zn with Sn by heating. CONSTITUTION:The surface of a cold rolled low carbon steel sheet is tinned to form an Sn layer by 0.2-1g/m<2> per one side. A Zn layer is further formed on at least one side by galvanizing by 0.01-0.3g/m<2> so that the amt. of the Zn layer is regulated to 2-30wt.% of the amt. of the Sn layer. The steel sheet is then heat treated to form a Zn-Sn alloy layer and to vanish the Zn layer. Thus, a surface treated steel sheet for a vessel having superior characteristics such as rust resistance in the naked state, seam weldability and corrosion resistance after painting is obtd. at a low cost.