Impact toughness of the duplex stainless steel SAF 2304, with heating between 1100 degrees C y 1300 degrees C

In the present investigation the impact toughness of a SAF 2304 duplex stainless steel, subjected to heating between 1100 degrees C and 1300 degrees C during a time of 30 minutes, was evaluated. The working conditions were, original condition, heating at 1100 degrees C, 1200 degrees C and 1300 degrees C for 30 min respectively. After the heat treatment to the tensile and impact specimens, the mechanical tests of tension, impact and hardness were carried out. The samples prepared metallographically were observed by the optical microscope (MO) and scanning electron microscope (SEM). It was observed the presence of inclusions with high proportion of aluminum, chromium, among others. From the Vickers microhardness test, an increase in microhardness was observed in the ferrite phase in the three conditions applied to the heat treatment compared to the original condition. For the austenite phase there is an increase of micro hardness Vickers for the conditions of 1100 degrees C and 1200 degrees C compared to the original condition while at 1300 degrees C it reduced with respect to the original condition. It was determined that there is a slight decrease in the impact toughness at 1100 degrees C and 1200 degrees C compared to the original condition while at 1300 degrees C a small recovery of its capacity to absorbed energy is carried out.