邊導器機構矯正鋼胚熱軋變形之模擬分析

Simulation and Analysis on the Camber and Wedge Corrections of Steel Slab during Hot Rolling Process

戴瑋廷(Tai, Wei ting)

指導教授 ： 敖仲寧

國立中正大學/工學院/機械工程學系/碩士(2012年)

摘要

在鋼廠熱軋製程中，加熱爐位於輸送線側邊，由於加熱爐門持續打開使橫移置產線的鋼胚在寬度方向產生溫度梯度，再經由後續道次軋延後會形成楔形截面(Wedge)與縱向彎曲(Camber)現象，此兩種現象會影響完軋後鋼帶的品質。
本研究在軋輥前後加入一對可動的邊導器機構來修正縱向彎曲現象，並將熱軋產線現有的兩種控制模式邊導器置入數值模型，分別為位置控制模式與力量控制模式。而軋延過程中，邊導器雖能有效矯正縱向彎曲現象，但邊導器矯正鋼胚的過程會影響軋輥裁減處的鋼胚厚度，也就是鋼胚的楔形截面量持續在改變；因此將數值模型的軋輥皆加入彈簧元素，藉此使模擬結果能更接近真實產線的結果。
本文利用有限元素軟體ABAQUS建立粗軋數值模型，並依照熱軋產線給予的操作條件進行設定，其鋼胚形狀依照產線條件建立楔形截面鋼胚與縱向彎曲鋼胚進行模擬，模擬結果除了針對胚形進行探討，還包括軋延過程各時序的鋼胚中心線路徑、邊導器與軋輥的受力歷程、軋輥兩側的軋延力差、鋼胚兩側的厚度變化和軋輥處鋼胚的受力分佈與應力、應變分佈型態；藉由以上的結果瞭解邊導器對鋼胚的矯正機制與矯正過程對軋輥間的影響。

關鍵字

熱軋製程 ； 鋼胚縱向彎曲 ； 鋼胚楔形截面 ； 位置控制模式 ； 力量控制模式 ； 有限元素分析

並列摘要

In the beginning of the hot rolling process, the steel slab may experience a temperature gradient along its transverse direction due to the fact that the furnace is located on one side guide conveyer and the furnace door remains opend. The temperature gradient on the steel slab may cause camber along longitudinal direction and wedge of the transverse section after sizing press and horizontal rolling. These two phenomena will affect the quality and the geometry of the steel plate after rolling.
In the numenical model and analysis, a pair of moveable side guides are placed before and behind the hot rolling mill to correct camber. There are two control modes for the side guides, namely, the position control mode and the force control mode. During rolling process, the side guides can effectively correct the camber, however, the on-going correction of camber by side guides will continuously affect the steel slab thickness, i.e. the wedge of the slab cross section would also change accordingly. To compensate the gap variation between work roll, work roll in the numerical model to make the conditions of the FEM model more close to actual steel rolling line.
Finite element analysis using ABAQUS was applied to establish the numerical model for hot rolling process. Modeling of the steel slab shape and its boundary conditions was based on the actual geometrical and mechanical conditions of the hot rolling line. The effect of side guides on the camber and wedge of steel slab was systematically investigated throughout the results obtained from FEM analysis. The simulation result include billet shape at different stages, the instantaneous trace of billet centerline at different time steps, the loading history of side guides and horizontal rolls, the difference of rolling load between work side and drive side of roller, loading and stress and strain distribution at roll bite on the billet, and the thickness change of billet across the roller. By analyzing the above results, the mechanisms of the camber and wedge correction of the steel slab provided by the side guides between the rolls were investigated.

並列關鍵字

hot rolling ； camber ； wedge ； side guide ； finite element method

參考文獻

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