連鑄大鋼胚表面轉角直向裂之研究及改善成效

Investigation and Improvements of Longitudinal Corner Crack in Continuous Casting Bloom

胡立榮(L. J. Hu) ； 陳柏梁(B. L. Chen) ； 陳勝榮(S. J. Chen) ； 張學仁(H. J. Chang)

《鑛冶：中國鑛冶工程學會會刊》 28卷3期 (1984/09) Pp. 125-132

https://doi.org/10.30069/MM.198409_28(3).0012

摘要

轉角直向裂為連鑄大鋼胚常見的缺陷之一，經由研究及試驗得知，此缺陷係導因於模內凝固売與模壁脱離所生成的間隙，同時證實其與碳含量有密切的關係，尤以碳含量在0.08～0.10％時最易發生。藉改用澆鑄粉取代菜仔油做潤滑劑，並將銅模之圓角半徑由10mm→6mm→0mm→4mm逐步修改，以縮小鑄胚角部與模壁之間隙，而得較佳的熱傳導，減輕轉角直向裂之生成。試驗結果，以具稍斜度之4R鋼模改善效果最佳，可完全防止轉角直裂之發生。

並列摘要

Longitudinal corner crack is one of the major defects found in the continuously castg bloom. Through investigations and mill tests, it has been proved that the air gap generated between the solidified shell and copper mould wall is the most important factor causing longitudinal corner crack. Meanwhile, it has been shown that carbon content has large effects on the formation of longitudinal corner crack. It occurs most frequently for carbon contents of 0.08%-0.10%. Casting powder has been applied to substitute rapeseed oil as mould lubricant. Besides, the radius of corner quadrant of copper mould was gradually modified to improve the heat transfer in the mould. Consequently, the air gap between the corner of steel shell and mould wall could be minimized, and the formation of longitudinal corner crack was effectively depressed. Mill tests showed that 4mm corner radius mould with tapper had the greatest improvements on longitudinal corner crack.