退火处理对轧制结合镁/铝/钢复合板组织及力学性能的影响

Effects of Annealing Treatment on Microstructure and Mechanical Mroperties of Roll-bonded Magnesium/Aluminum/Steel Laminates

组装了304奥氏体不锈钢/1060铝/AZ31镁/1060铝/304不锈钢5层复合板坯,采用加热轧制复合的方法制得了包覆不锈钢的镁基层合板。研究了不同轧制下压量对复合板材拉伸性能的影响以及后续热处理对复合板材拉伸性能和显微组织的影响。结果表明,不同下压量层合板的拉伸曲线呈现出不同的下降趋势。当下压量为39%时,层合板具有最优的力学性能。对39%下压量的层合板进行不同温度的后续退火处理后,层合板的抗拉强度先上升后下降,屈服强度下降,伸长率先快速上升,然后下降,最后趋于稳定。退火后镁层组织发生明显变化,由大变形晶粒、孪晶和动态再结晶的组合形貌演变为均匀的等轴状晶粒。

The five-layer composite slab of 304 austenitic stainless steel/1060 aluminum/AZ31 magnesium/1060 aluminum/304 stainless steel was assembled. One kind of magnesium-based laminates coated with stainless steel was obtained by hot-rolled process. Both the effects of different rolling reductions on the tensile properties of the laminates and the effects of subsequent heat treatment on the tensile properties and microstructure of the laminates were studied. The results show that the tensile curves of laminates with different reductions show different downward trends. Laminates with the reduction of 39%have the best mechanical properties. After subsequent annealing treatments at different temperatures, the tensile strength of laminates with the reduction of 39% increase first and then decrease, the yield strength decreases, the elongation first increases rapidly, then decreases, and finally stabilizes. After annealing, the structure of the magnesium layer changes significantly,changing from the combined morphology of large-deformed grains, twins and dynamic recrystallization to uniform equiaxed grains.