摘要
在250~400℃初轧温度条件下,对铸轧态AZ31B镁合金板材进行四道次不同轧制路径的轧制试验,采用Axio Imager A2m金相显微镜对微观组织进行观察,采用WDW-E100D电子万能试验机对试样室温拉伸性能进行检测。综合研究不同初轧温度及轧制路径对轧后镁板的宏观成形性、微观组织和力学性能的影响。研究结果表明:轧后镁板组织性能与轧制工艺存在较强相关性。随初轧温度的升高,镁板屈服强度和抗拉强度均逐渐减小,伸长率逐渐增大;不同路径的交叉轧制对镁板边裂现象有较好的改善作用,初轧温度升至400℃后边裂消失;轧后镁板RD-ND截面与TD-ND截面微观组织分布一致,晶粒尺寸均为单峰正态分布特点,不同路径交叉轧制均能有效提高晶粒尺寸分布的均匀性,改善轧后镁板的各向异性,多道次交叉轧制对镁板晶粒细化及均匀化作用最明显。
Under the initial rolling temperatures of 250 to 400 ℃, AZ31B magnesium alloy sheets are rolled by four different rolling routes. Microstructures of the rolled sheets are observed by Axio Imager A2m Metallographic Microscope, and room-temperature tensile properties are detected by WDW-E100D Electronic Universal Testing Machine. Then the formabilities, microstructures and mechanical properties of the rolled sheets are analyzed by comprehensively considering different initial rolling temperatures and rolling routes. The results of the research indicate that： obvious correlation is revealed between rolling process and microstructures and mechanical properties of the rolled magnesium alloy sheets. Along with the rising of initial rolling temperature, yield strength and tensile strength of rolled sheets are gradually decreased, and elongation is increased; edge cracks have been greatly reduced by different routes of cross-rolling, and edge crack disappears at the initial rolling temperature of 400 ℃; the distributions of microstructures of RD-ND section and TD-ND section are similar, and unimodal normal distribution of the grain size is presented; The uniformity of the grain size distribution can be effectively improved and anisortropy can be weakened by different routes of cross-rolling; uniform, fine and equiaxial grain microstructures can be produced by multi-pass cross rolling process.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2017年第10期43-51,共9页
Journal of Mechanical Engineering
基金
NSFC-山西煤基低碳联合重点基金(U161020023)
山西省重点研发计划(201603D111004
201603D121010)
山西省"青年三晋学者"特聘教授支持计划
江苏省"双创团队"领军人才
晋城市科技计划(201501004-10)资助项目
关键词
AZ31B镁合金
轧制路径
组织性能
AZ31B magnesium alloy
rolling route
microstructure and mechanical property
