Study on steel deoxidation with Al-Ca compound alloy
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摘要: 通過Al-Ca復合合金鋼水脫氧的平衡熱力學計算,確定了鋼液的氧的質量分數在3×10-6~1×10-4條件下,1600℃時的Al-Ca復合合金脫氧產物的穩定區域圖.以此為基礎,假定鈣的收得率為100%,預測了鋼液在Al-Ca復合合金Ca/Al質量比為5,加入量為M kg;Al-Ca復合合金Ca/Al質量比為0.2,加入量為M kg;Al-Ca復合合金Ca/Al質量比為0.2,加入量為0.2M kg三種不同脫氧制度下夾雜物的演變歷程.結果表明,在Ca/Al=5,復合合金加入量使初始鋼液中的[Ca]為0.01%,[Al]為0.002%時,夾雜物在鋼液精煉過程中的演變歷程為:12CaO·7Al2O3(l)/CaO·Al2O3(l)→CaO (s)→12CaO·7Al2O3(l)/CaO·Al2O3(l)→CaO (s)→12CaO·7Al2O3(l)/CaO·Al2O3(l),并確定了固態和液態脫氧產物在脫氧過程中交替形成為最理想的Al-Ca復合合金脫氧制度,可為鋼鐵企業脫氧劑的選擇和應用提供參考和借鑒.Abstract: The thermodynamic diagram of calcium-aluminum-oxygen ternary system was determined through thermodynamic equilibrium calculation of liquid steel deoxidation. Based on this thermodynamic diagram and assuming 100% yield of Ca addition, the evolution mechanisms of inclusions with three different deoxidation schemes were predicted, including M kg addition of mCa/mAl=5 alloy, M kg addition of mCa/mAl=0.2 alloy and 0.2M kg addition of mCa/mAl=0.2 alloy. The calculated results show that the evolution history of inclusion is affected by both the addition quantity and Ca/Al mass ratio of Al-Ca deoxidizer. The optimal deoxidation scheme is that the Ca/Al mass ratio is 5 and addition quantity is M kg, which makes the initial[Ca] content of 0.01% and initial[Al] content of 0.002% in liquid steel. Under such a condition, the evolution history of inclusions is 12CaO·7Al2O3(l)/CaO·Al2O3(l)→CaO(s)→12CaO·7Al2O3(l)/CaO·Al2O3(l)→CaO(s)→ 12CaO·7Al2O3(l)/CaO·Al2O3(l), and the desirable alternative formations of solid and liquid inclusions can be realized during LF refining, which can greatly enhance the effective collision and promote the floating up of inclusions. The results can be applied in industry for steel deoxidizer selection and deoxidation operation.
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參考文獻
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