J. Cirne, R. Dormeval, et al.
J. Phys. IV France 134 (2006) 1175-1181
Effects of strain-rate and pre-fatigue on tensile properties of laser welded joint of high strength steel platesH. Kobayashi1, M. Daimaruya2, H. Tsuda3 and K. Horikawa1
1 Department of Mechanical Science and Bioengineering, Osaka University, 1-3, Machikaneyama, Toyonaka 560-8531, Japan
2 Department of Mechanical Systems Engineering, Muroran Institute of Technology, 27-1, Mizumoto, Muroran 050-8585, Japan
3 Suzuki Motor Co. Ltd., 300 Takatsuka-cho, Hamamatsu 432-8611, Japan
Published online: 26 July 2006
The impact tensile properties of laser welded butt joints of two kinds of high strength steel plates with the tensile strength level of 590 MPa and 780 MPa (denoted by HR590 and HR780, respectively), were investigated using split Hopkinson bar tensile testing apparatus. Impact tension tests for the joint specimens pre-fatigued were also carried out to examine the effect of pre-fatigue. There were no significant effects of strain-rate and pre-fatigue on the dynamic and quasi-static tensile strength of laser welded butt joints. However, the decrease in the elongation of HR780 welded joints subjected high cycle pre-fatigue was observed only at a high strain-rate. From the observation of fracture surface, it was found that the decrease in the elongation may be caused by a number of damages due to the combination of high cycle pre-fatigue and high strain-rate.
© EDP Sciences 2006