Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : December 22, 2018 - December 24, 2018
In past studies, the small punch (SP) test using SUS304 at different deformation rate is investigated and rate sensitivity of its fracture behavior is reported. The microstructure including strain-induced martensitic transformation greatly influences the fracture mode. However, the influence on the rate sensitivity of the fracture behavior is still unclear. To make clear the rate sensitivity, the previous result must be verified. Considering the actual application of SUS304, the SP test with deflection rate over 103/s is necessary to be investigated. In this study, the impact SP test based on the split Hopkinson pressure bar method is performed and the fractographic study using the scanning electron microscope is conducted. For a comparison, the SP test under a quasi-static condition is also carried out. From the above tests, the rate sensitivity on fracture behavior in SUS304 is investigated. As the result, negative rate sensitivity of maximum force as well as deflection and positive rate sensitivity of work-hardening can be captured in the force-deflection curves. In the fractographic study, a fracture surface due to a glide plane decohesion which cannot be seen in impact SP test is confirmed in the quasi-static SP test while elongated dimples can be observed in both conditions.
