Fatigue behavior of welded SM490A steel under low temperature

초록

The paper aims to evaluate the fatigue behavior and its probabilistic properties in welded SM490A steels, which is utilized in high speed train, under low temperatures. For the goal, the tensile and fatigue tests are performed under displacement control mode and constant amplitude loading cycles, respectively at various temperatures (293K, 263K and 233K). The static strengths for base and welded materials are increased with the decrease in temperature but, the welded material has a considerable amount of scatter in strength. Also, the fatigue behaviors are greatly influenced by the test temperature for both materials. Especially, the welded material exhibits severe reduction of the fatigue limit compared with the base material. The probabilistic properties of fatigue life are investigated through P-S-N (probabilistic S-N) approach and the curves are well in conformance with the experimental results. Also, the variations of fatigue life are greatly influenced by the temperature and this tendency is more remarkable in the welded material.