Effects of High Rate Shear on the Microstructure and Deformation and Fracture Behavior of Two High Strength Steels
Research and development rept.
DAVID TAYLOR RESEARCH CENTER BETHESDA MD SHIP MATERIALS ENGINEERING DEPT
Pagination or Media Count:
The shear localization behavior of two high strength stee ls was evaluated at loading rates ranging from quasi-static to impact. The steels evaluated were similar in yield strength, but had different levels of toughness. The steel with superior toughness was direct quenched DQ. The second steel was quenched and tempered QT. Fatigue precracked Dual Notched Shear DNS specimens, loaded in mode II in-plane shear, were employed. The objectives were to measure energy density variations with loading rate, estimate the temperatures achieved in the shear zones of the specimens and examine micromechanisms of localized shear deformation as related to the microstructures of the steels. Temperatures in the shear zones were estimated from energy absorption characteristics and compared with temperatures measured adjacent to the fatigue crack tips, to assess compliance with adiabatic conditions. Keywords High strength steels Dynamic loading Fracture Shear Micromechanisms of fracture Shear banding Ship materials Metallurgy.
- Properties of Metals and Alloys
- Marine Engineering