Examination of the Mechanical Properties of Steel S460 for Fire Available to Purchase

To establish a basis for calculating the load-bearing capacity of steel members made of S460 in a fire, corresponding to EN 1993-1-2, the mechanical properties of the micro-alloyed grain refined steel S460 under high temperatures have been examined. Two different types of steel have been considered: a normalized rolled S460 N and a thermo-mechanically rolled S460 M, that differ in their chemical composition and the temperature control during the hot-rolling process. On the basis of transient warm-creep tests, constitutive laws have been derived for the temperature range 20-900°C. The testresults show an increased strength of S460 M at elevated temperatures in comparison to S460 N. This is a result of the strain hardening caused by the thermo-mechanical rolling and the reduction of the creep-velocity caused by niobium- and titanium-precipitations. The data derived from the tests show that the stress-strain curves given in EN 1993-1-2 for S460 overestimate both the strength and the stiffness of the examined S460 N.