冷径向锻造身管壁厚方向变形不均匀性研究

为分析冷径向锻造身管壁厚方向变形的不均匀性,通过有限元软件、力学拉伸试验和织构研究了身管壁厚方向的变形场、力学性能和织构组分。研究结果表明:身管成形过程中,外表层和中间层材料存在较大剪切应力,受剪切应力的影响,身管壁厚方向各层材料流动速度不一致,引起身管锻造变形不均匀;受变形不均匀的影响,在身管中间层和外表层材料形成剪切织构({112}〈111〉,{110}〈001〉),导致锻后身管壁厚方向轴向强度性能存在明显差异,表现为外表层和中间层强度较低,内表层强度较高。为对锻后身管壁厚方向变形不均匀性进行控制,通过控制变量法分析了锻造比、尾端压强、轴向进给速度、锤头锻打频率和锤头角度对身管中间层剪切应力分布的影响规律。分析结果表明:选用较高的轴向进给速度和较小的锤头入口角可以降低成形身管壁厚方向的变形不均匀性。

Research on Deformation Inhomogeneity along Wall Thickness Direction of Cold Radial Forged Barrel

In order to analyze the deformation inhomogeneity along wall thickness direction of cold radial forging barrel, the deformation field, mechanical properties and texture components in the wall thickness direction are studied by means of finite element software, mechanical tensile test and texture analysis. The results show that large shear stresses exist in the outer and middle layers of barrel during the forming process. The flow velocity of each layer in the wall thickness direction is inconsistent due to shear stress, thus causing the uneven deformation of barrel. The shear texture ({112} 111，{110} 001) is formed in the middle and outer layers of barrel due to uneven deformation, which results in obvious difference in axial strength performance of barrel wall thickness direction after forging. The strengths of outer and middle layers are lower, and the strength of inner surface layer is higher. In order to control the inhomogeneity along the wall thickness direction of barrel after forging, the influences of forging ratio, tail pressure, axial feed speed, hammer head forging frequency and hammer angle on the shear stress distribution in the middle layer of barrel are analyzed by using the control variable method. The analysis results show that a higher axial feed speed and a smaller hammer inlet angle can be selected to reduce the deformation inhomogeneity along wall thickness direction of formed barrel. Key