QUASISTATIC STRAIN RATES’ EFFECT TO THE PROPERTIES OF ADVANCED STEELS FOR AUTOMOTIVE INDUSTRY

Abstract

The paper presents the findings of the strain rate effect, described in constitutive material models by strain rate sensitivity index m, to the strength and deformation material properties. These were evaluated from stress-strain diagrams recorded at tensile test using PC controlled testing machine TiraTEST 2300 according to STN EN ISO 6892-1. The high strength low alloyed steel H220PD, dual phase steel DP 600 and Trip steel RAK 40/70 were investigated at strain rates  = 0.0021, 0.083 and 0.125 s-1. The results indicate major influence of the strain rate to the strength properties while only minor influence have been found when evaluate the deformation properties. The results also shown single phase materials are more sensitive to the strain rate than dual phase materials.