热轧对连续挤压的AZ31镁合金板材组织和性能的影响

Influence of hot rolling on microstructure and properties of AZ31 magnesium alloy sheet processed by continuous extrusion

采用热轧法对厚度为8mm的连续挤压的AZ31镁合金板材进行减薄加工,实验得到了表面质量良好的AZ31镁合金板材,研究了轧制后AZ31镁合金板材的显微组织和(0002)基面织构极密度的变化规律,分析了热轧板材退火后的拉伸力学性能。结果表明:热轧后的AZ31镁合金板材晶粒组织均匀性得到改善,平均晶粒尺寸为9μm,板材性能得到显著提高,抗拉强度为266.4MPa,伸长率为10.2%;经300℃保温1h退火后平均晶粒尺寸为7.4μm,力学性能再次提高,抗拉强度为257.3MPa,伸长率达到27.0%。此外,热轧后的板材(0002)基面织构得到改善,随着轧制道次的增加,织构极密度逐渐增加。

The AZ31 magnesium alloy sheet with 8 mm thickness processed by continuous extrusion was thinned by hot rolling,and the AZ31 magnesium alloy sheet with good surface quality was obtained by experiments. Then,the change rules of its microstructure and pole intensity of( 0002) basal texture after rolling were studied,and the tensile mechanical properties of the hot rolled sheet after annealing were analyzed. The results show that the microstructure uniformity of the hot rolled AZ31 magnesium alloy sheet is modified,and the average grain size is 9 μm. Therefore,the properties of sheet metal are significantly improved,namely,the tensile strength is 266. 4 MPa and the elongation is 10. 2%. The average grain size of 7. 4 μm is obtained after annealing at 300 ℃ for 1 h,and the mechanical properties are significantly improved again with the tensile strength of 257. 3 MPa and the elongation of 27. 0%. In addition,the( 0002) basal texture of hot rolled sheet is improved,and the pole intensity increases gradually with the increasing of rolling pass.