Mechanical Properties of a Low Carbon Steel Shock-10aded by an Explosive

Stress-strain behaviors and ductile-to-brittle transition temperature were examined with a low carbon steel shocked in water by an explosive. With an increasing shock pressure, the yield stress gradually decreased to the minimum at a pressure of 1400 MPa. This minimum value was 62% of the stress for the specimen annealed prior to shock loading. From ageing characteristics of the specimen shock-loaded at 1400MPa, the above decrease in yield stress was supposed to be attributed to generation of free dislocations. Beyond 1400 MPa, the yield stress began to increase from the minimum with an increasing pressure. This behavior was brought about by occurrence of increased twinned grains. The transition temperature of a specimen shock-loaded at 1400 MPa was lower by 15 K than that of an as-annealed specimen, namely, 0.21 K of the temperature was lowered at every 1 MPa of the decrease in the yield stress.