(1. 東北大學(xué) 軋制技術(shù)及連軋自動化國家重點(diǎn)實(shí)驗(yàn)室，沈陽 110819；
2. 東北大學(xué) 秦皇島分校 資源與材料學(xué)院，秦皇島 066004)
摘 要: 采用單道次壓縮試驗(yàn)在溫度200~450 ℃、應(yīng)變率0.001~1 s-1范圍內(nèi)對AZ91D鎂合金的熱變形行為進(jìn)行研究。依據(jù)應(yīng)力-應(yīng)變曲線通過線性擬合和非線性回歸建立了AZ91D鎂合金熱變形下動態(tài)再結(jié)晶體積分?jǐn)?shù)模型，并通過二次程序開發(fā)實(shí)現(xiàn)了熱輥軋制過程的組織模擬。結(jié)果表明：隨著輥面溫度的升高和壓下率的增加，動態(tài)再結(jié)晶體積分?jǐn)?shù)顯著增加，單道次軋制過程動態(tài)再結(jié)晶發(fā)生不充分。多道次軋制過程有利于軋制過程動態(tài)再結(jié)晶充分發(fā)生，輥面溫度為300 ℃時，三道次軋制后動態(tài)再結(jié)晶體積分?jǐn)?shù)接近85%，在五道次軋制后動態(tài)再結(jié)晶基本完成；當(dāng)輥面溫度繼續(xù)升高至350 ℃時，三道次軋制后繼續(xù)進(jìn)行軋制會導(dǎo)致再結(jié)晶晶粒長大。實(shí)測金相組織分布與預(yù)測結(jié)果較為吻合，建立的動態(tài)再結(jié)晶模型可用于動態(tài)再結(jié)晶演變規(guī)律的定量模擬和定性分析。
關(guān)鍵字: 動態(tài)再結(jié)晶；熱輥軋制；鎂合金帶材；數(shù)值模擬；組織
（1. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China;
2. School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China）
Abstract:The hot deformation behavior of AZ91D magnesium alloy was studied using single-pass compression experiments at temperature of 200-450 ℃ and strain rate of 0.001-1 s-1. An exponential function model was proposed to describe the dynamic recrystallization volume fraction equations of AZ91D magnesium alloy based on stress-strain curves. The numerical simulation of microstructure in heated roll rolling of magnesium alloy was realized through embedding the developed program into the finite element software platform. The results show that, with the increase of roll surface temperature and reduction, the dynamic recrystallization volume fraction increases obviously, and the dynamic recrystallization is incomplete during single pass rolling. The multi-pass rolling process is conducive to the full occurrence of dynamic recrystallization. When the roll surface temperature is 300 ℃, the dynamic recrystallization fraction is close to 85% after three passes of heated roll rolling, and the dynamic recrystallization is completed after five passes. Furthermore, the dynamic recrystallization grain sizes will grow up with more rolling passes than three passes or higher roll surface temperature than 350 ℃. The measured results are in agreement with the values predicted by the model, and the dynamic recrystallization model is significant to microstructure simulation and parameter optimization of AZ91D alloy in hot plastic deformation.
Key words: dynamic recrystallization; heated rolling; magnesium alloy strips; numerical simulation; microstructure
