Analysis of billet solidification & heat transfer and AlN precipitation on Q420C angle steel
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摘要: 為研究Q420C角鋼在大矯直應變過程中的鑄坯凝固傳熱行為以及AlN析出對鑄坯和軋材質量的影響,本文通過ProCAST模擬軟件和射釘試驗,對不同參數條件下鑄坯表面和角部溫度以及坯殼厚度等進行模擬計算,并提出了凝固坯殼厚度修正公式.通過Gleeble實驗得出,鑄坯在1008~1364℃溫度范圍內時具有較好的熱塑性.對AlN析出的熱力學和動力學研究表明,鑄坯應避開在AlN析出"窗口"內矯直,軋制前加熱爐均熱溫度控制在1160~1200℃,終軋溫度控制在850℃以上可減少AlN在奧氏體晶界沉淀析出.經過工藝試驗,成功開發出Q420C角鋼,軋材平均合格率達到90%,綜合性能指標滿足要求.Abstract: This investigation sought to determine the effect of solidification & heat transfer behavior and AlN precipitation on the quality of a Q420C billet and rolled product during the process of high straightening strain. To accomplish this, the paper employed a ProCAST simulation and a nail-shooting experiment to calculate the surface and corner temperature of the billet and the thickness of shell, and a formula for the thickness of solidified shell was proposed. The slab has a good plasticity in the temperature range of 1008-1364℃ based on the results of the Gleeble experiment. The thermodynamics and kinetics of AlN precipitation show that the billet should be straightened avoid the "window" of AlN precipitation and before steel rolling, the billet temperature should be controlled to between 1160-1200℃, and the final rolling temperature should be above 850℃. This reduces AlN precipitation in the austenite grain boundary. After the test, the Q420C steel was successfully produced. The average qualified rate of the rolled products reached 90% and the comprehensive performance index met the needed requirements.
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Key words:
- angle steel /
- Q420C /
- large straightening strain /
- ProCAST simulation /
- AlN precipitation
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參考文獻
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