Method for reuse of steel sheet scrap

Abstract

A recycling method of scrap steel plate that can recycle scrap steel plates including scrap of high-tensile steel plate to produce good quality of cast iron efficiently, while avoiding unnecessary cost increase. In the recycling method, scrap of high-tensile steel plate and scrap of ordinary steel plate are collected together in a batch collecting process and, then, in a preparing process, the scrap steel plates collected are melted and if not less than 0.7 weight % manganese is contained in the hot metal, then the hot metal is prepared so that a sulfur content in the range of 0.02 to 0.2 weight % in the hot metal and rare earth element or misch metal which is two times as much as the sulfur content is added to the hot metal. To obtain spheroidal graphite cast iron, spheroidizing agent (which preferably comprises no rare-earth element but comprises bismuth) is added further to the hot metal after that.

1 . A recycling method of scrap steel plate comprising: 
 a batch collecting process of collecting together scrap of high-tensile steel plate and scrap of ordinary steel plate, and    a preparing process of melting the scrap steel plate collected, wherein if not less than 0.7 weight % manganese is contained in the hot metal, then the hot metal is prepared so that a sulfur content is in the range of 0.02 to 0.2 weight % in the hot metal and rare earth metal or misch metal which is two times as much as the sulfur content is added to the hot metal.    
     
     
         2 . The recycling method of scrap steel plate according to  claim 1 , wherein after the addition of the rare earth metal or misch metal, spheroidizing agent is added to the hot metal.  
     
     
         3 . The recycling method of scrap steel plate according to  claim 2 , wherein the spheroidizing agent comprises no rare-earth element but comprises bismuth.