Abstract:  In the refining production of LF-RH of 42CrMoA alloy structural steel， the original production process and the industrial test technology of steel inclusion removal by nitrogen addition and release method were carried out， and the good experimental results were obtained. Through systematic sampling， it was found that adding nitrogen through bottom blowing during the LF refining process can increase T［N］ in the steel to 260 × 10^-6， and meet the demand of nitrogen release in the form of bubbles during RH vacuum refining process； Nitrogen addition and release method also had good total oxygen removal effects， after RH vacuum treatment， the average T［O］ content reduction can reach 37.4%； Nitrogen addition and release method also had good inclusion removal effect， the number of inclusion per unit area can be reduced from the original 8.771 pieces / mm² to 3.585 pieces / mm² after treatment， and the removal rate can reach 34.6%； In all kinds of inclusions， nitrogen extraction method had the highest removal efficiency of alumina inclusion， the proportion of Al₂O₃ inclusion in steel can be reduced from 83% to 74% after treatment， which effectively improved the cleanliness of 42CrMoA alloy structural steel.

Key words:  , Nitrogen Addition and Release Method； Increase Nitrogen； Inclusions； Total Oxygen； RH Refining； 42CrMoA Steel

摘要： 在42CrMoA合金结构钢LF-RH精炼生产中，进行了原生产工艺和增氮析氮法去除钢中夹杂物技术工业试验研究，获得了良好的实验效果。通过系统取样，发现在增氮析氮法LF精炼过程中，通过底吹增氮法可使钢中T［N］含量增至260×10^-6以上，满足RH真空精炼过程中以气泡形式析氮的需求；增氮析氮法还具有良好的全氧去除效果，经RH真空处理后，平均T［O］含量下降率可达37.4%；增氮析氮法也具有良好的夹杂物去除效果，经处理后单位面积夹杂物数量由原有的8.771个/mm²降为3.585个/mm²，去除率达34.6%；在各类夹杂物中，增氮析氮法对氧化铝夹杂去除效率最高，处理后可将钢中Al₂O₃夹杂比例由83%降为74%，有效提升了42CrMoA合金结构钢洁净度。

关键词: 增氮析氮法, 增氮, 夹杂物, 总氧, RH精炼, 42CrMoA钢