GCr15轴承钢RH和VD真空精炼过程钢洁净度对比

摘要：对比了RH和VD真空精炼工艺生产的GCr15轴承钢精炼过程的洁净度水平，研究了钢液中总氧（TO）、总氮（TN）、总硫（TS）以及夹杂物变化规律。轴承钢对洁净度要求较高，RH精炼工艺在降低钢中TO、TN含量，固相夹杂物去除，循环效率上均具有优势。经过RH精炼后，钢液中TO含量下降了61%，TN含量下降了15%，夹杂物数密度降低了75%；VD精炼过程中，钢渣反应剧烈，脱硫效果优异，VD精炼后钢液中TS含量下降了50%，但钢液循环速率远落后于RH精炼，且更容易发生卷渣。不同液相分数的夹杂物与钢液的接触角不同，液相分数小于27%的夹杂物与钢液不润湿，容易碰撞长大和上浮去除，而液态夹杂物黏附功更大，难以从钢液中去除。

Cleanliness of GCr15 bearing steel refined by RH and VD vacuum processes

Abstract：The cleanliness of GCr15 bearing steels produced by RH and VD vacuum refining processes was compared. Evolutions of total oxygen (TO), total nitrogen (TN), total sulfur (TS), and inclusions were investigated. Bearing steel has high requirements for cleanliness. RH refining has advantages in reducing TO and TN content, removing solid inclusion, and circulating efficiency. After RH refining, the TO content in molten steel decreased by 61%, the TN content decreased by 15%, and the number density of inclusions decreased by 75%. The stirring of slag and steel was strong during the VD refining, which was beneficial to the desulfurization, the TS content in liquid steel decreased by 50%. The circulation rate of the liquid steel in the VD refining was much lower than that in RH refining. The stronger stirring of slag and steel during VD refining resulted in the slag entrainment. The contact angle between inclusions with different liquid phase fractions and liquid steel is different. Inclusions with liquid phase fraction less than 27% are not wetted with liquid steel and are easy to collide, grow and float up for removal, while the adhesion work of liquid inclusions is greater and difficult to remove from liquid steel.