304不锈钢旋压件机械扩径工艺研究

发布时间：2018-06-24 21:21

本文选题：304不锈钢 + 机械扩径　；参考：《燕山大学》2015年硕士论文

【摘要】：304不锈钢筒形旋压件是某航天院研究所研制的一种产品。旋压后的筒形件横截面椭圆度增大,不能满足产品的技术要求,制品母线的直线度也存在改善的空间。因此,产品研制单位提出采用机械扩径技术来消除制品成形精度超差现象的设想。机械扩径技术是一种普遍使用的塑性成形工艺方法,被广泛应用于薄壁旋压筒形件、大直径直缝焊管、大直径螺旋焊管及其它大中型管筒形零件的最终成形。本文通过理论分析、MARC有限元数值模拟和实验,对304不锈钢筒形旋压件机械扩径技术进行了系统研究。研究内容包括:扩径变形过程及变形特征分析、扩径工艺参数和模具形状尺寸对制品质量的影响,304不锈钢管机械扩径实验设计。通过仿真模拟发现,管坯经“整圆”、“扩径”和“卸载”三个阶段完成变形过程。模具外圆半径、边缘圆角半径、塑性扩径率、管坯初始椭圆度及直线度分别对制品横截面椭圆度、壁厚分布、回弹及直线度产生不同程度的影响。经实验研究后发现,304不锈钢经过旋压后出现明显的加工硬化现象,屈强比达到0.9以上,强度变高,塑性变差,传统的机械扩径工艺很难实现对制品的整形。
[Abstract]:304 stainless steel cylinder spinning part is a kind of product developed by the Institute of Aerospace Research. The ellipticity of the cross section of the cylinder after spinning can not meet the technical requirements of the product, and there is room for improvement of the straightness of the product busbar. Therefore, the product development unit put forward the idea of using mechanical diameter expansion technology to eliminate the phenomenon of product forming precision overshoot. Mechanical diameter expansion is a widely used plastic forming method, which is widely used in the final forming of thin wall spinning tube, large diameter straight welded pipe, large diameter spiral welded pipe and other large and medium tube shape parts. Based on the theoretical analysis of Marc finite element numerical simulation and experiment, the mechanical diameter expansion technology of 304 stainless steel cylindrical spinning parts is studied systematically. The research contents include: the analysis of the deformation process and deformation characteristics of the expanding diameter, the influence of the process parameters and the shape and size of the die on the quality of the products, and the experimental design of the mechanical diameter expansion of 304 stainless steel tube. Through simulation, it is found that the deformation process of the tube billet is completed by three stages: "whole circle", "expanding diameter" and "unloading". The outside circle radius, edge radius, plastic diameter expansion rate, initial ellipticity and straightness of tube billet have different effects on cross section ellipticity, wall thickness distribution, springback and straightness, respectively. After experimental study, it is found that the working-hardening phenomenon is obvious after spinning. The flexural strength ratio is more than 0.9, the strength becomes higher, and the plasticity becomes worse. It is very difficult to realize the plastic shaping of the products by the traditional mechanical expanding process.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG306

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