Method for solving internal defect of small-area-reduction-percentage rolled piece and cross wedge rolling mold of method

Abstract

The invention belongs to the technical field of metal plastic molding, and particularly provides a method for solving the internal defect of a small-area-reduction-percentage rolled piece and a cross wedge rolling mold of the method. The cross wedge rolling mold is designed, wherein according to the determined target height H and the rolled piece original diameter d, the 0.5-1.5 Pi d protruding end face from the wedging position of the mold to the rear portion of the mold serves as a molded top face heightening segment, the top face height of the molded top face heightening segment is increased by delta, the value of the delta ranges from 0.2%d to 0.8%d, and the unit is mm; and then a slope is adopted, the molded top face heightening segment is in natural transition to an oval releasing finishing segment, and a blank is heated to the rolling temperature and is conveyed to the position between two cross wedge rolling molds obtained through design. By the adoption of a small-area-reduction-percentage shaft part produced through the cross wedge rolling mold design method, the internal defect easily and generally appearing can be overcome, the internal quality problem of the cross wedge rolling small-area-reduction-percentage shaft part is simply and effectively solved, the blank does the rotational motion under the effect of the mold, and the rolled piece with the small area reduction percentage is manufactured in a rolled manner.

Description

technical field [0001] The invention belongs to the technical field of metal plastic forming, and in particular provides a method for solving the center defect of a rolling piece with a small section shrinkage rate and its wedge, which is adapted to solve the problem of the center defect of a rolling piece with a small section shrinkage rate in cross-wedge rolling. Cross rolling die. technical background [0002] The cross-wedge rolling process has the advantages of high efficiency, material saving, and good production environment. It has been widely used in forming solid shaft parts. One of the main problems of the parts, especially the small reduction of area, is the greater chance of loose and cavities in the rolled parts. When cross-wedge rolling forms a rolled piece with a reduction in area of ​​less than 30%, the surface of the rolled piece is deformed, it is not easy to penetrate into the inside, and the metal axial flow is difficult. Part of the metal accumulates i...

AI Technical Summary

Problems solved by technology

Usually, the center defect can be controlled by changing the process parameters of the mold, but for the rolled piece with small section shrinkage, the effect of changing the forming angle is not significant, and reducing the widening angle will lead to an increase in the length of the roll surface of the mold

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