关键词: 55SiCrA弹簧钢, Al₂O₃-SiO₂-CaO精炼渣系, 夹杂物成分和形态

Abstract: The effect of ingredient and basicity ( 1.0 ~ 1.2 ) of (/% :) 38. 5 ~ 45. 8CaO-38. 2 〜42. 0SiO₂ -8 ~ 15 Al₂O₃-8MgO refining slag series on morphology of inclusions in spring steel 55SiCrA (/% : 0. 53C, 1. 50Si, 0. 70Mn, 0. 69Cr, 0. 008P, 0. 003S, 0. 005 Als) has been studied silicon-molybdenum tube furnace with Al₂O₃ crucible in laboratory, and the thermodynamic calculation on ingredient of inclusions and the analysis on distribution of inclusions in ternary phase diagram are carried out by using thermodynamic software Factsage. Results show that with increasing Al₂O₃ content in refining slag the Al₂O₃ content in inclusions increases, as the basicity of slag is 1. 2 with 8% Al₂O₃ , the inclusions in steel are distributed at low melting point area in Al₂O₃-SiO₂-MnO ternary phase diagram and the Al₂O₃ content in inclusion is 30% ~40% . Thermodynamic calculation results show that as basicity of slag is 1.0 ~ 1. 2 the corresponding Als in steel is 0. 008% that meets the examination results. Therefore it is available to control the morphology of inclusions in spring steel by using low basicity 1.0 ~ 1. 2 and ≤8%Al₂O₃ refining slag.