High-temperature stress-rupture data for the analysis of dangerous goods tank-cars exposed to fire

Abstract

This paper contains tension and stress-rupture test data on sample railroad tank-car steels at room temperature and temperatures between 500 and 720 °C. The paper describes the test facility, applicable standards, and procedures that were followed during the tests of tension and stress rupture. The paper also contains a simple correlation for the data and gives examples of how it can be used to predict tank failure times when exposed to fire heating. The stress-rupture testing was conducted at constant load (tensile force) conditions. A sample was heated to a specified temperature and the load was applied. The time to failure was then recorded. This testing was needed due to a general lack of available data for the high-temperature stress rupture of tank-car steels. These data are needed for the purposes of predicting tank failure when tank-cars are exposed to heating by fire. The steel samples were obtained from a recent train derailment in Ontario, Canada, and the steel samples included both new and older steels. Samples were cut in both the hoop and longitudinal directions to see if the stress-rupture properties were isotropic. Excellent data were obtained with very little data scatter in each sample. The results show that stress-rupture properties vary from sample to sample. Some older steels were as good as new steels, and some were not. However, all samples were nearly isotropic when it came to high-temperature stress rupture.