异型管无芯棒辊挤成型过程挤压力公式的建立

异型管无芯棒辊挤成型是一种生产高精度异型管的新技术。该成型方式的特点是力能消耗少、制品表面质量好，且施力形式为推力。该成型是在三向压应力的状态下完成的，变形过程中管子在长度方向上的延伸受到限制，管角部充填性能好，可以获得最小的各边相接处的外半径Ｒ值和更高的加工精度，特别适用于生产大直径厚壁或小型薄壁精密异型管。介绍了使用主应力法建立异型管无芯棒辊挤成型过程挤压力的计算公式。

Establishment of calculation formula of extrusion force during non-mandrel/roll-extrusion forming operation for shaped seamless steel tubes

As a new technique for manufacture of high-precision shaped seamless steel tubes, the non-mandrel/ rollextrusion forming process features low energy consumption, fine surface quality and pushing force in terms of force-applying way. Witht this process, tube formation is completed under a condition of three-directional pressure-stress, resulting in longitudinally restriction of elongation of the tube, good corner filling and minimum outer radius value R at the joint points between the sides as well as mush higher processing accuracy, and being. particularly applicable for manufacture of large-sized, heavy-wall or small-sized thin-wall precision shaped seamless steel tubes. Also described in the article is how to use the main stress method to establish the calculation formula for extrusion force applied to during non-mandrel/ roll-extrusion process of shaped seamless steel tubes