RH真空处理对高碳铬轴承钢尖晶石夹杂物的影响  

Influence of RH vacuum treatment on spinel inclusions of high carbon chromium bearing steel

作　　者：王昆鹏 王郢 谢伟 徐建飞 陈廷军 姜敏[4] WANG Kun-peng;WANG Ying;XIE Wei;XU Jian-fei;CHEN Ting-jun;JIANG Min(Steelmaking Factory,Zenith Special Steel Co.,Ltd.,Changzhou 213011,Jiangsu,China;Zenith Special Steel Co.,Ltd.,Changzhou 213011,Jiangsu,China;Technology Center,Zenith Steel Group Co.,Ltd.,Changzhou 213011,Jiangsu,China;School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中天特钢有限公司炼钢厂,江苏常州213011 [2]中天特钢有限公司,江苏常州213011 [3]中天钢铁集团有限公司技术中心,江苏常州213011 [4]北京科技大学冶金生态工程学院,北京100083

出　　处：《钢铁》2023年第1期108-115,共8页Iron and Steel

摘　　要：钢中尖晶石夹杂物不仅会恶化钢的可浇性,还可能导致成品出现宏观夹杂物,RH真空处理是去除钢中夹杂物的重要环节。对RH真空处理过程高碳铬轴承钢夹杂物数量、成分和类型变化开展研究,通过热力学计算讨论了真空压力对高碳铬轴承钢尖晶石夹杂物稳定性的影响。试验结果表明,当真空压力为30 Pa时,真空处理10 min,钢液循环总量达200~400 t,尖晶石夹杂物全部消失。真空处理15 min,夹杂物总数大幅降低,由480个/(200 mm^(2))降至97个/(200 mm^(2)),夹杂物总数减少80%。真空处理后,钢中液态夹杂物数量增加且夹杂物呈高度液态化,与真空处理前相比,液态夹杂物的数量由44个/(200 mm^(2))增至71个/(200 mm^(2)),增加61%,液态夹杂物占比由9%增至73%。尖晶石夹杂物全程为单一颗粒状,未发现其碰撞、聚集现象。热力学计算表明,真空条件下,高碳铬轴承钢中尖晶石夹杂物可被钢中碳还原分解,温度为1600℃时,临界分解压力为16000~22000 Pa,真空度越高,越有利于尖晶石夹杂物的还原分解。真空压力为4900 Pa时,真空处理7~14 min,钢液循环总量达511~1022 t,尖晶石夹杂物即完全消失;真空度为20400 Pa时,即便延长处理时间至40 min,将钢液循环总量增至2360 t,尖晶石夹杂物仍存在。与夹杂物被“物理去除”的观点相比,真空条件下,尖晶石夹杂物被钢中碳还原分解能更好地解释真空过程尖晶石夹杂物的变化特征。Spinel inclusions in steel not only deteriorate the castability of steel,but also may lead to macroscopic inclusions in finished products,and RH vacuum treatment is an important step to remove the inclusions in steel.The number,composition and types of inclusions of high carbon chromium bearing steel in RH vacuum treatment were studied,and the influence of vacuum pressure on the stability of spinel inclusions in high carbon chromium bearing steel was discussed through thermodynamic calculation.The experimental results show that when the vacuum pressure is 30 Pa,the total amount of liquid steel circulation reaches 200-400 t after 10 min of vacuum treatment,and all the spinel inclusions disappear.After 15 min of vacuum treatment,the total number of inclusions decreased from 480/(200 mm^(2))to 97/(200 mm^(2)),and the total number of inclusions decreased by 80%.After vacuum treatment,the number of liquid inclusions in steel increases and inclusions become highly liquid.Compared with that before vacuum treatment,the number of liquid inclusions increases from 44/(200 mm^(2))to 71/(200 mm^(2)),an increase of 61%,and the proportion of liquid inclusions increases from 9%to 73%.The spinel inclusions were single granular throughout the whole process,and no collision or aggregation was found.Thermodynamic calculation shows that the spinel inclusions in high carbon chromium bearing steel can be reduced and decomposed by C in the steel under vacuum condition.At 1600℃,the critical decomposition pressure is 16000-22000 Pa.The higher the vacuum degree,the more conducive to the reduction and decomposition of spinel inclusions.When the vacuum pressure is 4900 Pa,the total amount of liquid steel circulation reaches 511-1022 t after 7-14 min of vacuum treatment,and the spinel inclusion disappears completely.When the vacuum degree is 20400 Pa,spinel inclusions still exist even when the treatment time is extended to 40 min and the total circulating volume of liquid steel is increased to 2360 t.Compared with the view that inclusions a

关 键 词：轴承钢 RH真空处理 尖晶石夹杂物 压力 热力学 

分 类 号：TF769.4[冶金工程—钢铁冶金]