Mechanical properties of an austenitic stainless steel at elevated temperatures

In the Laboratory of Steel Structures at Helsinki University of Technology, an extensive experimental research has been carried out during the years 1994-1997 for investigating mechanical properties of various structural steels at elevated temperatures. The latest research was concentrated on an austenitic stainless steel grade named by Polarit 725 (AISI 304, EN 1.4301). The purpose of this research was to study the behaviour of this stainless steel material at fire temperatures using mainly transient state tensile test method. The material was also tested using steady state test method. The tests were carried out for both base material taken from a virgin cold-rolled steel sheet and for strongly cold-formed material taken from a small rectangular hollow section. The test results were used to determine the temperature dependencies of the mechanical properties i.e. yield strength, modulus of elasticity and thermal elongation of stainless steel grade EN 1.4301(AISI 304) at temperatures up to 900 degrees C.