Abstract
An example of computer engineering of a resource-efficient technological strategy for the production of cold-rolled steel using a two-stand reversible mill is presented. Strips 0.9 mm thick of high-strength IF steel of quality classes 220 and 260, doped with phosphorus, were obtained. The yield strength of the hot-rolled steels was revealed and approximations of the metal hardening curves were obtained. Using models of distribution of reduce , tension and speed for cold rolling, which take into account the peculiarities of the process at two-stand reversing mills, the problem of determining the maximum thickness of a hot-rolled stock at various required widths of the strip is solved. Using computer-aided design, taking into account a set of restrictions on the loads of stands and drives, rolling speed, flatness and roughness of the strip, it was found that the total reductions recommended to ensure the specified properties of the finished product can be provided with a strip width of up to 1250 mm. At the same time, the thickness of the hot-rolled stock with increasing width decreases from 3.4 to 3.0 mm for steel of quality class 220 and from 3.0 to 2.9 mm for steel of quality class 260. For equivalent section sizes, rolling speeds and mill capacities of different quality classes are practically the same. The test rolling results confirmed the values and the nature of the change in process parameters that were found as a result of computer-aided design.
Keywords:
high-strength IF-steel, metal hardening curves, cold rolling process, two-stand reversing cold rolling mill, cold rolled strip of maximum width, hot-rolled strip of maximum thickness, mechanical properties of cold-rolled strip, surface roughness of cold-rolled strip