北京科技大学学报
北京科技大學學報
북경과기대학학보
JOURNAL OF UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING
2014年
4期
424-431
,共8页
郭靖%程树森%程子建%张志华%张鹏
郭靖%程樹森%程子建%張誌華%張鵬
곽정%정수삼%정자건%장지화%장붕
炼钢%钙处理%氧化铝%夹杂物%变性%动力学模型
煉鋼%鈣處理%氧化鋁%夾雜物%變性%動力學模型
련강%개처리%양화려%협잡물%변성%동역학모형
steelmaking%calcium treatment%alumina%inclusions%modification%kinetic models
将Al2 O3以及固态的钙铝酸盐均视为未反应核,确定铝离子在液态钙铝酸盐层的扩散是铝镇静钢钙处理后Al2 O3夹杂物变性的限制性环节,由未反应核模型建立了Al2 O3夹杂物变性的动力学模型,并且通过热力学分析计算了模型参数。模型结果显示:随着Al2 O3夹杂物直径的增大,其完全变性为液态钙铝酸盐的时间大幅延长。钢液中Ca在一定范围内增加,不仅在热力学上有利于Al2 O3变性,也使其变性速率迅速增大,但Ca超过一定值时对变性速率促进减弱。温度升高不利于Al2 O3夹杂物变性反应,从而使变性的驱动力减小,对夹杂物变性促进作用不很明显。模型结果与工业试验和夹杂观察结果基本相符。
將Al2 O3以及固態的鈣鋁痠鹽均視為未反應覈,確定鋁離子在液態鈣鋁痠鹽層的擴散是鋁鎮靜鋼鈣處理後Al2 O3夾雜物變性的限製性環節,由未反應覈模型建立瞭Al2 O3夾雜物變性的動力學模型,併且通過熱力學分析計算瞭模型參數。模型結果顯示:隨著Al2 O3夾雜物直徑的增大,其完全變性為液態鈣鋁痠鹽的時間大幅延長。鋼液中Ca在一定範圍內增加,不僅在熱力學上有利于Al2 O3變性,也使其變性速率迅速增大,但Ca超過一定值時對變性速率促進減弱。溫度升高不利于Al2 O3夾雜物變性反應,從而使變性的驅動力減小,對夾雜物變性促進作用不很明顯。模型結果與工業試驗和夾雜觀察結果基本相符。
장Al2 O3이급고태적개려산염균시위미반응핵,학정려리자재액태개려산염층적확산시려진정강개처리후Al2 O3협잡물변성적한제성배절,유미반응핵모형건립료Al2 O3협잡물변성적동역학모형,병차통과열역학분석계산료모형삼수。모형결과현시:수착Al2 O3협잡물직경적증대,기완전변성위액태개려산염적시간대폭연장。강액중Ca재일정범위내증가,불부재열역학상유리우Al2 O3변성,야사기변성속솔신속증대,단Ca초과일정치시대변성속솔촉진감약。온도승고불리우Al2 O3협잡물변성반응,종이사변성적구동력감소,대협잡물변성촉진작용불흔명현。모형결과여공업시험화협잡관찰결과기본상부。
Al2 O3 and solid calcium aluminate were considered as un-reacted cores, the diffusion of aluminum cations in the liquid calcium aluminate layer was confirmed as the rate determining step of Al2 O3 inclusion modification, and further a kinetic model of Al2 O3 inclusion modification was established on the basis of the un-reacted core model. The model parameters were calculated by ther-modynamic analysis. Modelling results show that the time of Al2 O3 inclusion modification to completely liquid calcium aluminate will be much longer when the size of Al2 O3 inclusions increases. Moreover, increasing the Ca content in a reasonable range is beneficial not only to modify Al2 O3 inclusions to liquid calcium aluminate from thermodynamics but also to speed the modification process whereas the enhancement weakens when the Ca content exceeds a critical level. Temperature rise is disadvantageous to Al2 O3 modification chemical reaction so the driving force of Al2 O3 inclusion modification decreases correspondingly, namely temperature rise is not so obvious to speed Al2 O3 inclusion modification. Finally, the kinetic model results were verified by industrial trials and they accord with each other very well.