Experimental study on the fatigue behavior of corroded steel wire

To investigate the fatigue behavior of corroded steel wire, the fatigue tests of 102 natural corrosion steel wires in service for 23 years and 84 artificial prefabricated steel wires with corrosion pits have been carried out. The influences of corrosion degree and pit parameters on the fatigue life are discussed. The relationships between fatigue fracture, S-N curve and corrosion degree are studied, and the expression of S-N curves of corroded steel wire is established. The results show that the fatigue fracture is mainly related to the corrosion degree and can be divided into four kinds, such as conical shape, oblique shape, cup-shaped and stepped shape. The fatigue life of steel wires without corrosion damage in service is still significantly lower than that of the new ones at the low stress amplitude, and the degradation ratio is as high as 23%. The fatigue life degradation of steel wire with prefabricated pits is as high as 95% compared with that without corrosion under low stress amplitude. Therefore, the lower the stress amplitude, the higher the corrosion degree, and the more significant the degradation of fatigue life is. The low stress amplitude makes the fatigue crack propagation of steel wires fully, and there are multiple fatigue crack source regions and some of them appear multiple cracks. In addition, the influences of corrosion time and pit depth on the fatigue life are higher than pit width. (C) 2020 Elsevier Ltd. All rights reserved.