12Cr17Ni7不锈钢“鼓形”隔片充液成形工艺研究

Hydroforming Process of 12Cr17Ni7 Stainless Steel“Drum Type”Spacer

目的研究充液成形工艺参数对直升机旋翼球面径向弹性轴承球面“鼓形”隔片零件成形质量的影响规律。方法针对“鼓形”隔片零件形状复杂、成形难度大、精度和生产效率要求高等问题,选用充液成形工艺,通过有限元仿真技术,分析初始液室压力、凸模位移、成形压力对零件起皱、破裂、厚度分布、成形精度等的影响规律。结果数值模拟得到的优化工艺参数为初始液室压力3 MPa、凸模位移3 mm、成形压力30 MPa,验证试验成形出的“鼓形”隔片零件未发生破裂、起皱等缺陷,且零件成形精度良好、厚度分布较为均匀。结论对于“鼓形”隔片零件充液成形,凸模位移过小易造成流料不充分,导致后续成形过程减薄严重、厚度分布不均匀,凸模位移过大易造成零件起皱。合理的初始液室压力可在一定程度上减少起皱缺陷发生。成形压力过小易造成成形精度差,过大则易导致破裂发生。

The works aims to study the effects of hydroforming process parameters on the forming quality of spherical“drum type”spacer parts for spherical radial elastic bearing of helicopter rotor.To solve the complex shape,difficult forming,high precision and production efficiency requirements of“drum type”spacer parts,the effects of initial liquid chamber pressure,punch displacement and forming pressure on wrinkling,fracture,thickness distribution and forming accuracy were analyzed by finite element simulation.The optimized process parameters obtained by numerical simulation were initial liquid chamber pressure 3 MPa,punch displacement 3 mm and forming pressure 30 MPa.The“drum type”spacer parts formed in the verification test had no wrinkling,fracture and other defects.The forming accuracy was good,and the thickness distribution was uniform.In hydroforming of“drum type”spacer parts,too small initial liquid chamber pressure is easy to cause insufficient flow,resulting in serious thinning and uneven thickness distribution in the subsequent forming process;excessive punch displacement is likely to cause wrinkling of parts.Reasonable initial liquid chamber pressure can reduce wrinkling defects to a certain extent.Too small forming pressure is likely to cause poor forming accuracy,and too large forming pressure is likely to cause fracture.