Mechanical properties of structural steel at elevated temperatures

Abstract

A wide research program carried out in the Laboratory of Steel Structures at Helsinki University of Technology has investigated mechanical properties of different structural steels at elevated temperatures by using mainly transient state tensile test method. Some main test results from the high-temperature tests of structural steels S350GD+Z and S355J2H are presented in this chapter with a short description of the testing facilities. Structural steel S350GD+Z is a commonly used steel grade used in thin-walled steel structures and S355J2H is a common steel material used in tubular steel structures. The aim of the research presented in this chapter is to produce accurate material data for the use in different structural analyses. The main test results are public and they are available for other researchers. The mechanical properties of structural steel after cooling down, that is the residual strength, are also shortly examined and these test results are given in this report. The behavior of steel S355J2H seems also to be very promising. The increase of strength due to cold-forming seems to remain quite well at elevated temperatures. This should naturally be taken into account when estimating the behavior of cold-formed steel structures. Also, the strength after high-temperature tests seems to remain quite well.