Technological Aspects of Minimization of the Sizes of a Continuous Casting-Rolling Unit in the Production of Wire Rods from Fire-Refined Copper

In the production of wire rods made of fire-refined copper by minor and medium regional producers, the problem of minimization of the sizes of technological lines of continuous casting-rolling machines (CCRM) is most often solved by decreasing the number of structural components in the applied technological system, including the decrease in the number of rolling stands in the roll mill train. We estimate the influence of minimization of the number of rolling stands under the conditions of continuous casting-rolling in a 9-stand rolling mill of the Southwire Company on the ease of realization of the process of production and the quality of the products. It is shown that the realization of stable rolling process and the required quality of wire rods becomes possible as a result of decreasing the cross-sectional area of the original continuously cast ingots in the form of a trapezoid by 6.71% and an increase in the area of workpieces in all stands of the mill with an aim to prevent the overflow of the passes with the metal (the so-called “fin” defects), which enables one to get finished product with transformed “lap” defects. It is shown that the section of transition from the rough group of stands to the finishing group, i.e., the 3v stand (round pass), should be regarded as the most problematic from the viewpoint of formation of fin-type defects. We also perform the correction of the shape of plane oval specified for this stand. The practical implementation of the entire proposed complex of technological adjustments makes it possible to stabilize the process of rolling and to obtain copper wire rods 8 mm in diameter with regular geometric shapes and the required quality of macrostructure of the metal in the absence of lap-type defects.