Research on Non-metallic Inclusions of Gas Cylinder Steel

Aiming at gas cylinder steel produced by EAF-LF-VD-CC route in a domestic steel mill,the quantity and changes of total oxygen,microinclusions and macroinclusions in the liquid steel at different steps of total process were studied by the way of sampling systematically and comprehensive analysis.The results show that the quantity of microinclusions decreases from 16.7个/mm² to 6.1个/mm² after LF and VD refining.The inclusion is not modified completely during wire feeding.The molten steel has been reoxidized severely in tundish.The total oxygen is(10±2)×10^-6 in round billet,and macroinclusion in it is 0.2 mg/kg.