【作者】 邸洪双； 李永林； 宁忠良； 刘相华； 王国栋；

【Author】 Di Hongshuang Li Yonglin Ning Zhongliang Liu Xianghua Wang Guodong (State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang, 110004)

【机构】 东北大学轧制技术及连轧自动化国家重点实验室；

【摘要】 本文利用水平式双辊铸轧机,用液态镁合金直接制备镁合金薄带坯,同时采用快速冷却和压力下凝固成形新技术,改善镁合金的凝固组织,提高镁合金的可加工性。在实验室现有的铸轧机上成功地铸轧出厚度为1.4-3.5 mm,宽度为200-254 mm的AZ31B镁合金薄带,铸轧状态的镁合金薄带表面光洁,边部整齐。对铸轧状态的镁合金薄带显微组织分析的结果表明,采用双辊铸轧新工艺可以极大地细化晶粒、消除偏析、促使组织均匀化。铸轧状态的抗拉强度达到225 MPa。利用实验室现有的加热装置和轧制设备,对铸轧镁合金薄带进行了冷轧、热轧和退火等后续加工实验研究。研究结果表明,用铸轧方法制备的镁合金薄带具有良好的塑性,在室温下轧制累积变形程度可达30%以上,在240-300℃进行热轧最大压下率达到了40%。X射线衍射结果表明,铸轧状态的AZ31镁合金薄带不存在γ(Mg17Al12)、仅为α(Mg)相,铝以固溶态存在于α(Mg)中,因此使得其塑性得到提高。更多还原

【Abstract】 In order to improve the poor workability and solve the problem of difficult roughing rolling of magnesium billet, the twin roll strip castor ( TRSC ) was used for the manufacture of magnesium thin strip directly from its molten metal. Because the cooling rates achieved by TRSC casting process are in the range of five hundred to several thousands of degrees per second and the strip is formed under the pressure, therefore, this near- rapid solidification process can leads to homogeneity of microstructures, refined grain size and increased solid solubility. The experiments were carried out on the existing e-quipments at State Key Laboratory of Rolling and Automation ( RAL) , Northeastern University. Strip samples 200- 254 mm wide and 1. 4 - 3. 5 mm thick have been successfully cast in standard AZ31B alloy. The surface of the as cast magnesium strip is smooth and the edge is tidy. The microstructure a-nalysis result of the as cast magnesium strip shows that the gain size is much refined compare to that of ingot samples, and there is no segregation in the strip. The tensile strength of the strip in the cast state is about 225 MPa. The as cast magnesium strips were cold rolled directly on a two-high rolling mill, the total reduction up to 40% can be reached. X- ray diffraction result shows that the main phase in the as cast state AZ31B magnesium strip is α (Mg) , the γ(Mg17Al12) phase existing in the conventional wrought magnesium A231B sheet is vanished, therefore, the ductility of the strip is increased.更多还原