不同挤压方法对6082合金棒材粗晶环的影响

Effect of Different Extrusion Methods on Coarse Grain Ring of 6082 Alloy Bar

采用相同20MN挤压机、不同挤压方法进行6082棒材挤压试验,使用光学显微镜、电子万能试验机、光谱分析仪对6082试样进行检测分析,研究了制品力学性能、宏观金相组织的粗晶与微观组织的晶粒度等级。结果表明,正向挤压制品基体晶粒度优于反向挤压制品基体晶粒度,可达7级;反向挤压制品皮质层晶粒度等级大于正向挤压制品皮质层晶粒度等级;正向挤压棒材低倍组织中出现粗晶环且尺寸达到3.5mm,不符合技术要求,而反向挤压棒材低倍组织中粗晶环尺寸符合技术要求。在保证低倍无粗晶的条件下,力学性能抗拉强度最高可达379MPa,屈服强度可达364MPa,伸长率可以达到16.5%。

In this paper,different extrusion method is used in 20MN extrusion machine to carry out 6082 bar extrusion experiment.Optical microscope,electronic universal testing machine,spectrum analyzer are used to test the 6082 sample,and the mechanical properties of the products,macro metallographic organization of coarse grain and grade of its microstructure.The results show that the forward extrusion products matrix grain degree is better than that of backward extrusion products matrix grain degree,it is up to level 7.Backward extrusion products cortex grain size grade is greater than the forward extrusion products.Forward extrusion rod in macrostructure and coarse grain ring size is 3.5mm,and not conform to the requirements of the technology,and backward extrusion rod macrostructure of coarse grain ring size can meet the technical requirements.Under the condition of guarantee low power without coarse grain,the mechanical properties of tensile strength up to 379MPa,yield strength is up to 364MPa,the elongation can be up to 16.5%.