Study on the Interactive Damage Behavior of U75V Rail Salt Spray Corrosion and Rolling Wear

Abstract

Abstract. The railway lines in coastal areas in Southeastern China are dense. When operating in such an environment, steel rails are subjected to the combined effects of coastal environmental corrosion and wheel–rail wear, which make them highly susceptible to severe damage. This susceptibility leads to a shorter service life of the rails and higher maintenance expenses. Therefore, studying the friction and damage behavior of rails under corrosive conditions in coastal environments is highly important. Wheel–rail rolling contact fatigue tests were conducted on steel rail samples that were subjected to various numbers of corrosion–wear interaction cycles. The tests were carried out using a neutral salt spray testing machine and a dual-roller friction and wear tester. After the tests, the corrosion rate and wear-rate were calculated by analyzing the mass loss. After each corrosion or wear test was completed, the surface topography of the sample was characterized and analyzed using scanning electron microscopy (SEM). The results show that corrosion induces progressive degradation of rail materials and compromises the structural integrity of the sample surface. Following the synergistic interaction between corrosion and abrasion, surface defect phenomena such as spallation and crack initiation occurred on the samples, which were accompanied by the accumulation of corrosion products, thereby leading to an increase in stress concentration during subsequent wear. This increase in the stress concentration was reflected in the test data as increases in the friction coefficient and the amount of wear. Moreover, wear induced the formation of defects such as cracks, spalling pits, and surface delamination on the sample surfaces, which provided more attachment sites for the salt spray solution to deposit, thus expanding the contact area between the corrosive medium and the material and directly increasing the degree of corrosion. This interaction was not simply additive; instead, it occurred via the process of corrosion destroying the surface, wear expanding the damage, and the cycle intensifying the deterioration, thereby transforming the gradual failure of the material owing to corrosion or wear into sudden fractures or surface peeling under their interaction. Such an interaction significantly increases the safety risks of infrastructure in environments such as the ocean and atmosphere.