(北京交通大學 機械與電子控制工程學院，北京100044)
摘 要: 針對AZ31B鑄軋鎂合金板材溫熱拉深性能差的問題，提出預變形溫熱拉深工藝。對AZ31B鑄軋鎂合金板材在20~220 ℃進行預變形溫熱拉深實驗研究。結(jié)果表明：預變形使鑄軋鎂合金板材的拉深性能明顯改善，使AZ31B鑄軋鎂合金板材具有最佳拉深性能的沖頭溫度范圍(20~95 ℃)；凹模溫度選擇在160~220 ℃范圍內(nèi)，鑄軋鎂合金板材具有良好的拉深性能，極限拉深比可達到2.26；隨著拉深成形溫度的升高，工件中動態(tài)再結(jié)晶晶粒數(shù)量逐漸增加，220 ℃拉深成形時工件中再結(jié)晶晶粒分布趨于均勻。
關鍵字: AZ31B合金；鎂合金板材；雙輥鑄軋；預變形；溫熱拉深；極限拉深比
warm temperatures by pre-forming
（School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China）
Abstract:In order to solve the problem of the poor warm deep drawability of the twin-roll cast AZ31B Mg alloy sheet, a warm deep drawing process by pre-forming was proposed. The warm deep drawing experiments of twin-roll cast AZ31B Mg alloy sheets were examined by pre-forming at temperature of 20−220 ℃. The results indicate that the deep drawing performance is significantly improved by pre-forming. The punch temperature range of 20−95 ℃ is recommended to obtain the best drawability for the twin-roll cast AZ31B Mg alloy sheet. The twin-roll cast AZ31B Mg alloy sheets have good deep drawing formability at die temperature of 160−220 ℃ with the limit drawing ratio up to 2.26. The dynamic recrystallization (DRX) grains of the workpieces increase gradually with increasing temperature. And the DRX grains of the materials distribute evenly, when the workpieces are obtained at temperature of 220 ℃.
Key words: AZ31B alloy; Mg alloy sheet; twin-roll casting; pre-forming; warm deep drawing; limit drawing ratio
