ABSTRACT
Except in free-cutting steels, sulfur is considered to be a harmful impurity, since it causes hot shortness in steels. Some decades back, for common grades of steel cast through the ingot route, the maximum permissible sulfur content was 0.04%. In the continuous casting route, it should be 0.02%. In special steel plates, the normal specification for sulfur is 0.005% these days, but there is a demand for ultra-low-sulfur (ULS) steel with as low as 10 ppm (0.001%), e.g., in line pipe, HIC resistive steels, and alloyed steel forgings.
