为减少汽车废气再循环(Exhaust Gas Recirculation,EGR)管件三维弯曲缺陷,提高成品率,本文建立了304不锈钢本构模型,采用数值仿真与实验相结合方法对模型成形参数中相对壁厚、相对半径对管材的最大主应变、最大壁厚减薄率等影响因素进行探索,分析相对壁厚、相对弯曲半径对管材弯曲过程中成形质量的影响.结果表明,管材在弯曲成形过程中,相对壁厚越小,相对弯曲半径越小,则管材越容易产生裂纹以及失稳起皱等缺陷;随着弯曲角度的增大,管材弯曲最大壁厚减薄率值的增大趋于平缓.对于易发生塑性变形的金属材料,其相对壁厚及相对弯曲半径的取值是否合适是减少其裂纹产生的关键因素.故研究结果可为获得高质量的管件提供理论支撑.
Analysis of the influence of process parameters on the quality of three-dimensional bending forming of automotive EGR pipes
In order to improve the yield rate and reduce three-dimensional bending defects in automotive EGR pipes,a constitutive model for 304 stainless steel is developed in this study.A combined approach of numerical simulation and experimental analysis is used to investigate the effects of relative wall thickness and relative radius on the maximum principal strain and maximum thinning rate of the pipes during forming.The impact of relative wall thickness and relative bending radius on the forming quality of the pipes is also analyzed.The results demonstrate that pipes with smaller relative wall thickness and relative bending radius are more prone to defects such as cracks and instability wrinkles during the bending forming process.Furthermore,the increase in the maximum thinning rate of the pipes during bending becomes less significant as the bending angle increases.The appropriate selection of relative wall thickness and relative bending radius is crucial for reducing crack formation in metal materials that are susceptible to plastic deformation.These findings provide valuable theoretical support for achieving high-quality pipe fittings.
NETL
NSTL
万方数据
