Improvement of Hot Ductility in a Low-Carbon Steel by the Application of the Precooling

Abstract

The effect of precooling on hot ductility of a low-carbon steel is investigated. It shows a wide reduction of ductility in the temperature range of 700-900 degrees C with a general hot tensile test. The hot ductility is increased by applying precooling before the hot-tensile test. The increase in the reduction of area (RA) reaches 40-50% when the steel is precooled to 500 degrees C. Active precipitation of (Mn, Cu)-sulfide is observed during the precooling. The increased RA is attributed to the active sulfide formation, which decreases sulfur segregation at grain boundaries.