长钢管的大变形量镦粗工艺及模具设计

Process and die design for large deformation upsetting process of long steel tube

针对长钢管大变形量镦压加工难等问题,开展了镦压工艺计算与设计,建立了钢管的高径比、镦压变形量与镦压质量之间的关系。在镦压工艺和模具设计上对坯料可能产生的失稳和制品内、外径保证问题进行了评价,并进行了镦压试验,提出了解决因长钢管大变形量镦压而导致失稳倾向和制品易折叠的镦压加工方法,规定了模具工作过程及注意事项。研究结果表明,长钢管接受镦压加工时,若其高径比和镦压总变形量大大超过镦压加工规范时,采取两次镦压、在毛坯内径中加装芯棒和在外径外部设计模圈及对坯料进行酸洗、磷化、浸涂固体润滑剂等技术,可以有效地解决长钢管大变形量镦压加工难的问题。

Aiming at the problems of the machining process for the large deformation upsetting forming of long steel tube, the calculation and design of forging pressure processing were investigated. After the analysis of upsetting pressure process, the relationship between high-pressure pipe diameter ratio, upsetting pressure deformation and forging quality was established. A machining method was presented to solve the problems such as unstable and folding phenomenon for the upsetting pressure products. The possible instability of the stock and the outside and inside diameter of the products were evaluated on the process and die design, the upsetting pressure process was tested, moreover, the working process and precautions of the mold were provided. The results indicate that, if the ratio of height to diameter and upsetting pressure greatly exceeds the total deformation of upsetting pressure processing specification when long steel pipe upsetting pressure processing, the problems of the machining process for the large deformation upsetting forming of long steel tube can be solved using ways such as taking two upsetting pressure, the inner diameter of the blank with mandrel and the external diameter of blank with the design mode and blank circle for pickling,phosphating,coating of solid lubricant.