High Strain Rate Tensile Behavior of Advanced High Strength Steels with Martensitic Transformation 2020-01-0754
The mechanical behavior of high strength steel (AHSS) grades with tensile strengths up to 980MPa has been extensively studied. However, limited data is found in the literature on the tensile behavior of steels with tensile strengths of the order of 1180 MPa that deform via martensitic transformation, especially at nominal strain rates up to 500/s. This paper examines tensile flow behavior of four different 1180 MPa grade AHSS at nominal strain rates of 0.005/s, 0.5/s, 5/s, 50/s and 500/s using an experimental methodology that combines a servo-hydraulic tester and high-speed digital image correlation. Even though the strength increase with nominal strain rate is consistent between the four different materials, the total elongation increase with nominal strain rate varies widely. Some insights as to why this occurs from examination of the steel microstructures and variation of retained austenite volume fraction with strain are offered as an explanation.
Vesna Savic, Louis Hector, Rakan Alturk, Charles Enloe
General Motors LLC, Clemson University, CBMM North America