钢管内外高压润滑精密拉拔成形技术研究

发布时间：2018-04-02 18:25

本文选题：高压润滑　切入点：拔制力　出处：《燕山大学》2015年硕士论文

【摘要】：冷拔管由于其良好的性能,广泛用于我国工业建设中,有“工业血管”之称。然而,用于高新产品中的冷拔管与普通冷拔管不同,它要求管材的尺寸精度更高,表面质量更好。而传统的拉拔工艺生产的管材很难达到高精度管材的要求,拉拔后的产品仍需经过打磨抛光等工序才能达到要求。短芯棒管材拉拔工艺用于管材内外径尺寸及表面质量均要求较高的精密管材的拉拔生产。但由于芯棒与管材内表面之间的润滑散热不良,极易发生胶合,难于生产出合格的产品。钢管内外模高压润滑冷拔成形技术是基于短芯棒拉拔工艺的创新,采用边界润滑减小摩擦对拉拔过程的影响,减小拉拔力;且散热良好,从而提高了冷拔后管材的精度。本文主要研究工作有:1.考虑密封缸液体压力对管尾端的推力作用,推导出内外高压润滑拉拔条件下的拉拔力计算公式;2.利用有限元仿真软件MSC.Marc对管端缩口成形工艺过程进行模拟。重点研究了缩口成形极限及不同厚径比对管材成形极限的影响,并简单分析了应力分布规律及工艺参数对缩口力的影响;3.利用限元仿真软件MSC.Marc对冷拔过程进行模拟,分析了轴向应力、径向应力、剪应力、米塞斯应力的分布规律。研究了密封缸内压力对轴向应力的影响,并通过轴向应力模拟值和计算值的比较,证明了拉拔力公式的准确性;4.通过大量的模拟,分析了摩擦系数、模角、拉拔速度、断面收缩率及密封缸液体压力等对拉拔力的影响,从中得到了最佳模锥角,并对管材断面收缩的极限进行了研究;5.对实际生产遇到的问题进行了分析,并提出了解决措施。以上的研究成果,可为实际生产提供理论支持和技术指导。
[Abstract]:Cold-drawn tube is widely used in industrial construction of our country because of its good performance.However, the cold drawing pipe used in high-tech products is different from the common cold drawn tube, which requires higher dimensional accuracy and better surface quality.The pipe produced by traditional drawing process is difficult to meet the requirement of high precision pipe, and the product after drawing still needs to be polished and polished to meet the requirements.Short mandrel tubing drawing process is used in the production of precision pipe with high internal and external diameter and surface quality.However, due to the poor lubrication and heat dissipation between the mandrel and the inner surface of the pipe, it is easy to glue and produce qualified products.The technology of high pressure lubrication cold drawing for inner and outer die of steel tube is based on the innovation of short mandrel drawing process. Boundary lubrication is adopted to reduce the influence of friction on drawing process and to reduce drawing force, and the heat dissipation is good, thus improving the precision of the tube after cold drawing.The main research work of this paper is: 1.Considering the thrust effect of the liquid pressure on the end of the pipe, the formula for calculating the drawing force under the condition of internal and external high pressure lubrication drawing is deduced.Finite element simulation software MSC.Marc is used to simulate the forming process.The influence of shrinkage forming limit and different thickness / diameter ratio on the forming limit of pipe is studied emphatically, and the influence of stress distribution law and process parameters on shrinkage force is simply analyzed.The finite element simulation software MSC.Marc is used to simulate the cold drawing process and the distribution of axial stress radial stress shear stress and Mises stress are analyzed.The influence of the pressure in the seal cylinder on the axial stress is studied, and the accuracy of the drawing force formula is proved by comparing the simulated and calculated values of the axial stress.The influence of friction coefficient, die angle, drawing speed, cross section shrinkage ratio and liquid pressure of seal cylinder on drawing force are analyzed through a large number of simulations. The optimum die cone angle is obtained, and the limit of cross section shrinkage of pipe is studied.The problems encountered in actual production are analyzed, and the solving measures are put forward.The above research results can provide theoretical support and technical guidance for actual production.
【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】：TG356

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