针对中国铁路客车和货车轴箱轴承用钢主要使用电渣钢的现状,采用铁水+废钢→70 t 电弧炉→LF→RH→3 t钢锭→均热坑→1350+750/650轧机轧制的流程生产规格ϕ60～ϕ120 mm 8620钢(质量分数/%:0.18～0.22 C,0.15～0.30 Si,0.75～0.95 Mn,0.45～0.65 Cr,0.45～0.70 Ni,0.15～0.25 Mo,≤0.020 P,≤0.015 S,0.020～0.050 Al).通过控制出钢留钢留渣、炉后造渣和合金化,真空处理时间≥25 min,氩气弱搅拌,控制钢水过热度,全过程Ar气保护,模铸自动浇注,轧制后控制冷却等工艺措施,生产的产品宏观夹杂物检测含量≤10 mm/dm3,晶粒度8～8.5级,密度达到7.854 g/cm³,钢材各项指标满足标准要求.
Development of Rolled Steel Products from 3 t Ingot of Grade 8620 for Railway Axle Box Bearings
Based on the current quality situation of ESR bearing steel for passenger railway and wagons in China,the grade 8620 steel bars with diameters between 60 mm and 120 mm are produced with the process as follows:70 t EAF(Hot Metal+Scrap)→LF→RH→3 t steel ingot→soaking pit →1350+750/650 rolling mill,whose chemical composition are(%):0.18-0.22 C,0.15-0.30 Si,0.75-0.95 Mn,0.45-0.65 Cr,0.45-0.70 Ni,0.15-0.25 Mo,≤0.020 P,≤0.015 S,0.020-0.050 Al.By taking technological measures such as steel and slag retention operation,slag formation and alloy ad-dition during tapping,vacuum holding time≥25 min and soft argon blowing,superheat control,full process Argon protec-tion casting and automatic pouring as well as controlling cooling after rolling etc,to keep 8620 steel bars conform to all technical specification requirements,especially,macro-inclusions of finished bars less than 10 mm/dm³,grain size class 8-8.5,and the density being 7.854 g/cm³.
3 t Steel IngotGrade 8620 SteelAutomatic Ingot Casting,Macro-inclusionDensity
万方数据
