Blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method for ultra-fine grain bars

Abstract

The invention discloses a blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method for ultra-fine grain bars. On the basis of a three-way hydraulic forming machine, the die assembly force is provided through an upper slide block, and pressure required for forming of punches at the two ends is provided through a left slide block and a right slide block. A die inner cavity is a linear channel formed by sequentially connecting a first squeezing channel, a middle twisting channel and a second squeezing channel on the same straight line. The section area of the middle twisting channel is smaller than the section area of the first squeezing channel and the section area of the second squeezing channel. The punches at the two ends are located at the two ends of the linear channel in a one-to-one correspondence manner, and a blocked variable section cavity is formed through the reciprocating punches at the two ends. By means of reciprocating of the punches at the two ends, the reciprocating squeezing, twisting and upsetting process of a to-be-processed blank in the linear channel is achieved, and preparation of the ultra-fine grain bars is completed through multi-pass forming. By means of the blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method, bar grains can be effectively refined, the forming limit of the bars is improved, and the blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method is easy to operate, high in applicability and capable of being easily applied in an engineered manner.

Description

technical field [0001] The invention relates to the technical field of material preparation and processing methods, in particular to a closed-type variable cross-section reciprocating extrusion torsion forming method for ultra-fine grain rods. Background technique [0002] Metal bars are widely used in manufacturing, transportation, construction and other industries, and play an important role in the development of my country's national economy. Compared with ordinary bars, ultra-fine grain bars have higher strength and plasticity, and their economic benefits And the scope of application far exceeds that of ordinary rods. At present, the domestic production of ultra-fine grain bars mostly adopts the method of repeated hot rolling, but the repeated hot rolling process is complicated, the conditions are strictly controlled, and the requirements for equipment are relatively high, especially for mass production. In recent years, the method of using large plastic deformation proc...

AI Technical Summary

Problems solved by technology

However, in the existing large plastic deformation process, the deformation amount of multi-directional forging is limited, and the grain refinement effect is poor; the material structure obtained by equal-diameter angular extrusion is not uniform, and there is a problem of eccentric load of the punch during the deformation process ; High-pressure torsion refinement effect is good, but it is impossible to prepare large-size ultra-fine-grained materials, and its engineering application is limited

The existing large plastic deformation process is not suitable for the preparation of ultra-fine grain rods, and it is difficult to meet the requirements of industrial production for the preparation of ultra-fine grain rods

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