高强钢20MnTiB多工位冷镦变形行为  

Multi-stage Cold Forging Behavior of High Strength Steel 20MnTiB

作　　者：肖志玲[1] 刘百宣[1] 孙红星[1,2] 刘华[1] 

机构地区：[1]郑州机械研究所,郑州450001 [2]西安交通大学机械工程学院,西安710049

出　　处：《材料工程》2016年第3期77-83,共7页Journal of Materials Engineering

基　　金：国家科技重大专项资助项目(2013ZX04002081)

摘　　要：通过对高强螺栓多工位冷镦变形分区的金属流动、显微组织、力学性能及其变化规律进行分析,并采用Deform-3D数值模拟和实际产品成形相结合的方法,来研究高强材料的多工位冷镦变形行为。结果表明:多工位冷镦变形属于低动态变形;大、小变形区的宏观流线和显微组织有明显的"遗留性",而难变形区由于高强材料的"包辛格效应",铁素体由拉长的晶粒变成等轴晶粒,而珠光体的带状消失,组织"遗留性"最差;通过低动态多工位冷镦变形,20MnTiB高强钢微观组织中铁素体和珠光体均发生了形变强化,且硬度值的增幅相近。In order to study the multi-stage cold forging behavior of high strength metallic,the metal flow,microstructure and mechanical properties variation were discussed which the high strength bolts deformation division areas were formed by multi-stage cold forging technology,and used both Deform-3Dnumerical simulation and actual product deformation methods.The results show that multi-stage cold forging deformation belongs to low dynamic deformation;microstructure and flow lines of big/small deformation areas have obvious＂carryover effect＂;due to high strength materials＂Bauschinger effect＂,the ferrite grains is changed into equiaxed grains from elongated grains in difficult deformation area while the pearlite band is disappeared,so that the＂carryover effect＂of microstructure is worst in this deformation area;Both pearlite and ferrite in the microstructure of 20 MnTiB high strength steel occur working hardening by low dynamics multi-stage cold forging deformation,and the magnitude of increasing hardness number of the pearlite is fairly near ferrite.

关 键 词：高强金属材料 变形分区 遗留性 形变强化 

分 类 号：TG376.2[金属学及工艺—金属压力加工]