精炼渣中Al_(2)O_(3)质量分数对U71Mn重轨钢中夹杂物影响  

Effect of Al_(2)O_(3)mass fraction in refining slag on inclusions in U71Mn heavy rail steel

作　　者：高梓淇 张瑜 任强 张立峰 GAO Ziqi;ZHANG Yu;REN Qiang;ZHANG Lifeng(School of Mechanical Engineering,Yanshan University,Qinhuangdao 066044,Hebei,China;Ansteel Iron and Steel Research Institutes,Anshan 114009,Liaoning,China;School of Mechanical and Material Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]燕山大学机械与工程学院,河北秦皇岛066044 [2]鞍钢集团钢铁研究院,辽宁鞍山114009 [3]北方工业大学机械与材料工程学院,北京100144

出　　处：《中国冶金》2024年第10期26-36,共11页China Metallurgy

基　　金：国家重点研发计划资助项目(2023YFB3709900);国家自然科学基金资助项目(U22A20171)。

摘　　要：精炼渣对钢液洁净度有着非常显著的影响,主要起兼顾脱氧、脱硫及吸附夹杂物的作用。MnS是重轨钢中常见的非金属夹杂物,大尺寸长条状MnS对钢的性能有极大危害。基于促进MnS在氧化物表面非均质形核、减小A类夹杂物危害的思想,结合工业试验与热力学计算,讨论了渣中Al_(2)O_(3)对夹杂物成分、尺寸、分布的影响,发现渣中Al_(2)O_(3)质量分数由13.72%降低至7.23%时,钢中总铝质量分数由0.0024%降低至0.0020%,钢轨夹杂物中Al_(2)O_(3)质量分数由83.35%降低到75.07%,氧化物夹杂数量密度由2.90个/mm^(2)增加到5.69个/mm^(2),有利于增加MnS非均质形核位点,促进MnS在氧化物表面析出。评级结果表明,随着渣中Al_(2)O_(3)质量分数的降低,A法MnS评级粗系级别由2.0级下降至1.5级,细系级别由1.0级下降至0.5级;B法MnS评级粗系由0.744级下降至0.621级,细系保持在0.500级。热力学计算结果表明,渣中Al_(2)O_(3)含量通过影响渣中Al_(2)O_(3)活度来影响钢液中[Al]含量,从而影响夹杂物中Al_(2)O_(3)含量。控制MnS夹杂物在氧化物表面析出,有利于提高成品钢轨A类夹杂物的合格率。Refining slag has a very significant effect on the cleanliness of molten steel,and it mainly plays the role of deoxidization,desulfurization and inclusions adsorption.MnS is a common non-metallic inclusion in heavy rail steel.Large-size long strip MnS has great harm to the performance of steel.Based on the idea of promoting the heterogeneous nucleation of MnS on the surface of oxides to reduce the harm of class A inclusions,the influence of alumina ratio in slag on the composition,size and distribution of inclusions was discussed in combination with industrial test and thermodynamic calculation.It is found that when the mass fraction of alumina in slag decreases from 13.72%to 7.23%,the mass fraction of total aluminum in steel decreases from 0.0024%to 0.0020%,the mass fraction of Al_(2)O_(3)in rail inclusions decreases from 83.35%to 75.07%,and the number density of oxide inclusions increases from 2.90/mm^(2)to 5.69/mm^(2).It is beneficial to increase the heterogeneous nucleation sites of MnS and promote the precipitation of MnS on the surface of oxides.Rating results show that with the decrease of alumina ratio in slag,the coarse grade of MnS rating of A method decreases from 2.0 to 1.5,and the fine grade decreases from 1.0 to 0.5.The coarse grade of MnS rating of B method decreases from 0.744 to 0.621,and the fine grade remains at 0.500.The thermodynamic calculation results show that the proportion of alumina in slag affects the content of[Al]in the molten steel by affecting the activity of Al_(2)O_(3)in slag,thus affecting the content of Al_(2)O_(3)in the inclusions.Controlling the precipitation of MnS inclusions on the surface of oxides is beneficial to improve the qualified rate of class A inclusions in finished rails.

关 键 词：重轨钢 MNS 非均质形核 夹杂物 热力学 精炼渣 

分 类 号：TF769[冶金工程—钢铁冶金]