REFINEMENT OF STEEL FOR IMPROVING HYDROGEN INDUCED CRACK RESISTANCE

摘要

PURPOSE: A refinement method of steel with improved hydrogen induced crack resistance suitable for fabricating line pipes for sour gas service is provided. CONSTITUTION: In a refinement method of steel with improved hydrogen induced crack resistance including the processes of calcium powder injection into molten steel(2) tapped from converter; bubbling the molten steel for uniform mixing; degassing the molten steel; feeding Ca-Si wire into the molten steel; stirring the molten steel and continuous casting the molten steel, the method is characterized in that after top bubbling is performed to prepare ultra low sulfur steel, bottom bubbling is performed with a ladle(4) equipped with a porous cap(6) in above bubbling process; stirring process is accomplished by bottom bubbling.