Comparative Fatigue Analysis of Structural Steels Considering Welding and Surface Effects

ABSTRACT There are limited data on the very high‐cycle fatigue for structural steel welds for over 10 million cycles. The purpose of this research is a fatigue performance comparison of the welds made of steels S355JR+AR and S275JR+AR. The goal of reaching the gigacycle fatigue domain is achieved using the ultrasonic fatigue testing at 20 kHz. Fatigue samples are prepared to investigate the influence of two surface conditions—polished and precorroded. Fatigue failures are driven primarily by welding porosity with the fatigue life duration dependent on the size and location of pores. Visual comparison of fatigue data for steels poses a challenge, because of the vast scatter of experimental data points. Therefore, a statistical approach is used with a fatigue performance parameter applied to the fatigue data for welded samples to quantify the quality of the structural materials.