THE STRUCTURE AND THE CRITICAL DEGREE OF COLD DEFORMATION FOR SHEETS OF STEEL WITH LOW CARBON

摘要

In the paper we present experimental results carried on a steel with 0.04%C and 0.25%Mn used in deep drawing. The research was done on samples taken from rolled straps, treated and skin passed. For comparison, control samples were used, they were taken from the steel strap before cold rolling (they were hot rolled). The thermal processing of the cold rolled samples was done in industrial conditions in a bell furnace. The microstructures revealed that the samples with low deformation degrees processed in industrial conditions have a high unevenness of the granulation along the section of the strap. At higher deformation degrees (above 32.5%) the granulation gets more and more even as the deformation degree increases. The critical deformation degree was found to be around 6.5%.