Development of a resource-saving technology of production of strip-type profiles by drawing in roller dies using dummy passes

Abstract

The rolling-drawing process is used in the production of a large number of shaped profiles of complex configuration, including thin-walled, strip and periodic section profiles. This process, in comparison with drawing in monolithic dies, allows to reduce energy costs by 20–40 %, to increase deformation in one pass to 40–50 %, to reduce the number of preparatory operations (heat treatment, pickling), to exclude the use of expensive lubricants for drawing. Compared to the production of profiles by the method of cold rolling, the rolling-die process has a higher technological flexibility, does not require significant capital investments when organizing the production of precise profiles. At the same time, due to the presence of tensile stresses at the edges of the profile, which can cause their destruction, the assortment of strip-type profiles produced by this method was previously limited to readymade profiles with a ratio of width to height of no more than two. The authors of this work have previously developed a technology for the production of crimped steel strip with a width-to-height ratio of more than 10 by the rolling-drawing method. However, the developed calibration provides for a large number of transitions, complicates the organization of the production of strip profiles of a wide range of sizes, especially in the production of low-tonnage batches. To decrease the number of transitions, the use of dummy paases was proposed. It was shown that this will make it possible to increase the width-to-height ratio of strip-type profiles to 20, and, accordingly, reduce the production cost. The proposed technology for the production of strip-type profiles by the method of drawing in roller dies using dummy passes will allow to comprehensively solve the problem of providing machine-building and instrument-making enterprises by especially precise profiles of a wide range of sizes.