Creep Characteristics and Behavior of Fire Resistance Steel (FR355B) Exposed to High Temperatures

Fire resistance steel maintains strength at high temperatures and its allowable temperature is higher when compared with generic steel. Thus, it is needed to analyze its fire resistance quantitatively. In this study, high temperature creep tests of fire resistance steel specimens were conducted with variables of stress ratio and temperature to analyze their mechanical properties and behavior at a fire. The creep limit temperature of the Steel New (SN) steels observed from the high temperature tests was below 538 °C. The FR (Fire Resistance) steels showed stable creep behavior until 600 °C and maintained lower level of deformation for a longer period of time when compared with what was observed from previous studies. It is deduced that the FR steels are very effective in resisting deformation at high temperatures. As stress ratio increased, strain increased almost tenfold. Since strain increased very rapidly approximately from 1%, it is required not only to compare difference in final strain but also to quantitatively analyze creep behavior when strain is 0.5–1% and build up critical deformation data.