RETRACTED CHAPTER: High Temperature Thermal Properties of Vanadium Steel

Abstract

When steel framed structures are exposed to fire, the thermal response of steel plays a crucial role in determining fire resistance (FR). Due to changing thermal properties with temperature, the strength and stiffness of steel is lost at a greater rate under elevated temperatures as compared to concrete and wood. With the recent research and development, significant improvement in strength properties has been achieved and new types of steel such as vanadium steel have come to the construction industry. For FR evaluation, high temperature (HT) properties specific to vanadium steel are to be known. These properties vary with temperature and the composition (type) of steel. For vanadium steel, three thermal properties, namely thermal conductivity, specific heat, and thermal expansion were measured in 20-750°C (20-1000°C for thermal expansion) using state-of-the-art test equipment. For comparison purpose, conventional steel namely A36 was also considered in the test program. Using the data generated from the thermal property tests, HT property relations for vanadium steel are proposed as a function of temperature. The use of these HT property relations, developed specific to vanadium steel can lead to realistic assessment of FR of structural members made of vanadium steel. 1 Introduction Fire resistance (FR) evaluation through fire experiments and through occurrences of fire incidents indicate that two critical factors influence the fire performance of construction steel. These are temperature induced strength degradation and fire-induced forces resulting from thermal expansion of steel members. These two factors are temperature dependent and hence reliable prediction of temperatures in steel members becomes necessary. Thermal properties that influence temperature rise in steel include thermal conductivity, specific heat and thermal expansion. These properties can vary with composition of steel and also with rising fire temperatures. Vanadium steel is supposed to have different FR properties as compared conventional structural steels. Currently, due to lack of data on thermal properties of vanadium steel, the FR of