20CrMnTiH齿轮钢夹杂物控制体系  

Inclusion Control Hierarchy of 20CrMnTiH Gear Steel

作　　者：郑新伟 刘增平 张大伟 ZHENG Xinwei;LIU Zengping;ZHANG Dawei(Chengde Jianlong Special Steel Co.,Ltd.,Cbengde 067200,China;Hebei Provincial Key Laboratory of Semi-Molten Steel Smelting High Clean and High Quality Special Steel,Chengde 067200,China)

机构地区：[1]承德建龙特殊钢有限公司,河北承德067200 [2]河北省半钢水冶炼高洁净高品质特殊钢重点实验室,河北承德067200

出　　处：《工业技术创新》2022年第2期38-44,共7页Industrial Technology Innovation

摘　　要：齿轮钢是用于加工制造齿轮的钢材,齿轮钢中的夹杂物级别是影响齿轮寿命的关键因素。以20CrMnTiH齿轮钢为研究对象,形成囊括铁水预处理、转炉冶炼、LF精炼、真空脱气(VD)、方坯连铸等工艺流程的控制体系。一是将转炉终点温度从1 660℃调整至1 620℃,将终点碳含量从0.03%调整至0.08%,使得钢中氧含量从0.092%降低至0.034%;二是优化精炼渣系,将氧化钙含量由62%~66%调整至55%~60%,将三氧化二铝含量由25%~31%调整至32%~36%,将二氧化硅含量由6%~10%调整至4%~9%;三是在真空脱气工序中,将真空时间由12 min延长至18 min,促进氢、氧等元素的去除;四是在方坯连铸过程中,采取保护浇铸措施,避免钢水与空气接触,避免因二次氧化而产生夹杂物。试制结果表明:A类细系夹杂物由2.0级降低至1.0级、粗系夹杂物由1.0级降低至0.5级;D类细系夹杂物由1.5级降低至1.0级、粗系夹杂物由1.0级降低至0.5级。成品能够满足高质量品种要求。Gear steel is a kind of steel used to manufacture gears,and the inclusion level in the gear steel is a key factor affecting the life of gear.Taking 20CrMnTiH gear steel as the research object,a control hierarchy including hot metal pretreatment,converter smelting,LF refining,vacuum degassing (VD) and billet continuous casting was formed.Firstly,the end temperature of converter was adjusted from 1 660℃ to 1 620℃,and the end carbon content was adjusted from 0.03% to 0.08%,so that the oxygen content in the steel was reduced from 0.092% to 0.034%.Secondly,optimized was the refined slag system,adjusted were the content of calcium oxide (from 62%~66% to 55%~60%),aluminum oxide (from 25%~31% to 32%~36%) and silicon dioxide (from 6%~10% to 4%~9%).Thirdly,in the vacuum degassing process,the vacuum time was extended from 12 min to 18 min,which promoted the removal of elements such as hydrogen and oxygen.Fourthly,in the process of billet continuous casting,protective casting measures were taken to avoid the contact between molten steel and air,and avoid the inclusion caused by secondary oxidation.The trial-production results show:Class A fine inclusions are reduced from Grade 2.0 to Grade 1.0,and coarse inclusions are reduced from Grade 1.0 to Grade 0.5;Class D fine-grained inclusions are reduced from Grade 1.5 to Grade 1.0,and coarse-grained inclusions are reduced from Grade 1.0 to Grade 0.5.The finished products can meet the requirements of high-quality varieties.

关 键 词：20CRMNTIH齿轮钢 夹杂物 氧含量 精炼渣系 真空脱气(VD) 方坯连铸 

分 类 号：TF70[冶金工程—钢铁冶金]