Mechanical properties of pre-cracked high nitrogen steel under dynamic composite loading

Abstract In this paper, the mechanical properties of pre-cracked high nitrogen steel specimens with different loading angles of 30°, 45° and 60° were studied by using Hopkinson tension bar. The corresponding force-displacement curves under different loading angles were obtained. It was found that with the decrease of the pre-crack loading angle, the proportion of the shear stress on the specimens in the composite loading gradually increased, and the stress concentration appeared during the composite loading process, the fracture strength of the specimens decreased significantly. At the same time, however, the dispersion of the experimental results decreased, and the fracture morphology tended to be consistent with the elongation at break. The obtained mechanical properties of high nitrogen steel under combined loading can provide reference and basis for its technological improvement, safe production and reliable application