Tsuchida N.,University of Hyogo |
Yamaguchi Y.,Kobelco Research Institute |
Morimoto Y.,University of Hyogo |
Tonan T.,Kobe Steel |
And 2 more authors.
ISIJ International | Year: 2013
Effects of temperature and strain rate on tensile properties in metastable austenitic stainless steel SUS301L were studied in order to clarify the conditions of stress-induced martensitic transformation behavior for the maximum uniform elongation through the TRIP effect. The experimental results of the previously studied SUS304 steel were used to compare the conditions of metastable austenitic steels with different austenite stability. In the static tensile tests for the SUS301L steel at temperatures between 123 K and 373 K, the tensile strength increased with decreasing temperature, and uniform elongation reached a maximum at 323 K. The volume fraction of stress-induced martensite (Vα) at the same true strain increased with a decrease in temperature. For the strain-rate dependence on transformation kinetics, Vα decreased at strain rates higher than about 10-2 s-1 due to the temperature rise caused by adiabatic deformation. The equation for stress-induced transformation behavior proposed by Matsumura et al. was modified to consider the saturation value of stress-induced martensite, and the modified equation could describe the transformation kinetics precisely. The conditions of stress-induced transformation for the maximum uniform elongation through the TRIP effect were coincident between the SUS301L and the SUS304 with different austenite stability: the volume fraction of martensite at a true strain of 0.3 is approximately 5% and the maximum transformation rate is almost 2 at a higher true strain near uniform elongation. © 2013 ISIJ.
Takagi Y.,Employment and Human Resources Development Organization of Kyoto |
Takagi Y.,Kagawa University |
Takagi Y.,University of Hyogo |
Ueji R.,Employment and Human Resources Development Organization of Kyoto |
And 8 more authors.
Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan | Year: 2011
Synopsis: In order to investigate the effect of strain rate on TRIP effect in metastable austenitic steels, tensile deformation behavior of a JIS-SUS301L steel was examined at wide range of strain rates between 103/s and 10-3/s, in addition of the comparison with data of stable austenitic steel (JIS-SUS310S). Concerning of the SUS301L steel, the 0.2% proof stress increased and the uniform elongation decreased with increasing of strain rate. The tensile strength decreased with an increase in strain rate between 10 -3/s and 101/s and then increased again at strain rate more than 101/s. The significant difference between the strain rate dependences on tensile strength and uniform elongation of SUS301L and SUS310S was clarified especially at strain rates between 10-3/s and 10 0/s. As far as the effect of strain rate on stress-induced martensitic transformation behaviors is concerned, the volume fraction of stress-induced martensite at the same true strain decreased with increasing of strain rate. These stress-induced transformation behaviors were associated with the tensile strength and uniform elongation of SUS301L steel between 10 -3/s and 100/s. The conditions of stress-induced martensitic transformation in order to obtain better uniform elongation at a high strain rate of 100/s were discussed by the calculations using the Weng secant method.