超纯轴承钢的精炼工艺

通过控制电炉(供氧强度、渣中氧化铁比例、出钢挡渣率、出钢钢液的氧活度)、钢包炉(精炼渣系、脱氧剂、钢液温度、精炼时间、底吹氩压力、精炼钢包耐火材料的选择、铁合金种类的选择)、真空脱气(真空度、真空时间、底吹氩压力)的工艺参数以及真空后的软吹氩搅拌、并采用IPAS系统和控制钢液浇铸速度,使超纯轴承钢(SFGCr15)的w(S)、w(Ti)、w(O)分别达到0.003%、0.001 2%和0.000 7%以下,钢中非金属夹杂物也处于较好水平,满足了国际顶尖轴承厂家对轴承钢的超纯要求.

Refining Process of Superclean Bearing Steel

The sulphur,titanium and oxygen contents in superclean bearing steel(SFGCr15) are less than 0.003%,0.0012% and 0.0007% respectively and the content of non-metallic inclusions is at satisfactory level by controlling the technological parameters of EAF steelmaking(intensity of oxygen supply,content of(FeO) in slag,the rate of slag stopping at tapping,oxygen activity of liquid steel at tapping),LF refining(refining slag composition,deoxidizers,temperature of liquid steel,refining time,pressure of bottom argon blowing,the selection of refractory materials in refining ladle,the selection of ferroalloys),vacuum degassing(vacuum degree,time of vacuum degassing,pressure of bottom argon blowing) and soft argon stirring after vacuum degassing,adapting IAPS and adjusting the casting rate of liquid steel.In this way,the quality of SFG15 meets the requirements from top world bearing manufacturers.