Metallurgical and mechanical properties of two low alloy, TRIP assisted, multi-phase steels are investigated. Tension and compression experiments are performed over a range of strain rates and temperatures to determine the kinetics of the austenite to martensite transformation. The volume fraction of retained austenite is measured using neutron diffraction which provides measurements of high accuracy. Results are used to assess the energy absorption characteristics of the steels for use in crashworthiness evaluations.