Study of critical temperatures for an hypoeutectoid steel cooled by forced convection.

Morgan Stelmor industrial process is known, as the starting point for quality processing of wire rod products, obtaining good mechanical properties. This process guarantees excellent performance with high production rates. In order to process several steel grades and different diameters, it is necessary to determine, the different austenitization temperatures and cooling rates that will control austenitic grain growth and, consequently, the pearlite interlamellar spacing. In this work, dilatometric analysis was performed to determine critical temperatures for an hypoeutectoid steel during heating and controlled continuous cooling, similar to the industry conditions for heat treatment. Metallographic analysis and microhardness test validated the results obtained during the dilatometry tests. The critical temperatures will be employed to understand the effect of the thermal conditions in the Morgan Stelmor process and adjust the conditions for better results in the austenitic grain size.