Influencia de las altas temperaturas superficiales en las propiedades del acero al carbono ASTM A36

Abstract

The objective of this research project was to analyze the influence of high surface temperatures on the carbon steel properties ASTM A36. It began with the analysis of the state of the art, then continued with the experimentation of 12 mm thick steel plates. They were subjected to high surface temperatures, reaching temperature ranges between 700 °C to 1110 °C at different times of exposure. Once the experimentation was completed on each of the specimens, ultrasound tests were carried out using the ASTM E797/E797M-21 standard, metallographic analysis of the specimens based on the ASTM E3-11 standard, determination of the size of grain according to the ASTM E112-13 standard and finally the hardness is determined by the ASTM E10-18 standard. These tests were carried out in order to verify the changes in the steel properties. The results of the thickness and hardness tests after experimentation have provided average values, obtaining a thickness of 11,81 mm and hardnesses of 145 HB and 79,4 HRB in zone A, 138 HB and 76,8 HRB in zone B. Finally the presence of the ferrite and pearlite phases and a reduction in the steel grain size that went from 8,41 to 7,61 was evidenced. It was concluded that the thickness, hardness and steel grain size of ASTM A36 were reduced due to exposure to high temperatures in a time interval of 90 minutes and a distance of 100 mm. It is recommended to continue with research in this field applied to other types of carbon steel and cold cut metallographic samples to avoid phase changes.