Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire

Abstract

Cables are the main load-bearing components of a cable bridge and typically composed of high strength steel wires with a galvanized coating or Galfan coating. Galfan steel wire has recently started to be widely used because of its better corrosion resistance than galvanized steel wire. The corrosion characteristics of the coating and the difference in the corrosion fatigue process of the two types of steel wire are unclear. To further improve the service performance and maintenance of cable bridges, this study investigated the corrosion characteristics of galvanized steel wire and Galfan steel wire through accelerated corrosion tests and established a time-varying model of uniform corrosion and pitting corrosion of high-strength steel wire. Then, a long-span suspension bridge was taken as the research object, and the corrosion fatigue degradation of the two kinds of steel wire under a traffic load was analyzed on the basis of traffic monitoring data. The results showed that the uniform corrosion of the two types of steel wire conformed to an exponential development trend, the corrosion coefficient of galvanized steel wire conformed to the normal distribution, and the corrosion coefficient of Galfan steel wire conformed to the Cauchy distribution. The maximum pitting coefficient distribution of the two kinds of steel wire conformed to the generalized extreme value distribution. The location parameters and scale parameters of the two distributions showed an exponential downward trend with the increase of corrosion duration. When the traffic intensity was low, the corrosion characteristics of the steel wire was the main factor affecting its service life, and the average service life of Galfan steel wire was significantly higher than that of galvanized steel wire. Under a dense traffic flow, the service life of the steel wire was mainly controlled by the traffic load, and the service life of Galfan steel wire was slightly improved. Effective anti-corrosion measures are a key factor for improving the service life of steel wire.

Fatigue of Bridge Steel Wire: A Corrosion Pit Evolution Model under the Effects of Wind and Vehicles

“…Therefore, taking into account the requirements for both computational efficiency and accuracy, a cyclic load block accuracy of 0.5 years was selected for this study. 3) and ( 6), the damage variable Dt after that cycle can be determined using Equations (8) and (9). Using this data, the material parameters for the steel wire are updated to simulate the degradation of material performance, achieving the effect of material deterioration.…”

“…{ } After calculating ∆D e and ∆D p for each cycle based on Equations ( 3) and ( 6), the damage variable D t after that cycle can be determined using Equations ( 8) and (9). Using this data, the material parameters for the steel wire are updated to simulate the degradation of material performance, achieving the effect of material deterioration.…”

“…Hu et al [8] propounded a continuum damage mechanics (CDM) model to explore the realms of pre-corrosion and corrosion fatigue in aluminum alloys. Zhao et al [9], with a grounding in accelerated corrosion trials and traffic load data from a specific bridge, scrutinized the corrosion-fatigue degradation of wires under traffic loads, accentuating the pivotal, influential role of corrosion characteristics in service life, particularly under conditions of low traffic flow intensity. Importantly, the morphological alterations near the corrosion pits and the concomitant plastic fatigue damage during corrosion fatigue, factors often overlooked in prior numerical models, could significantly impact fatigue life.…”

Corrosion fatigue mechanisms and evaluation methods of high‐strength steel wires: A state‐of‐the‐art review

“…Figures 7 and 8 show the macroscopic and microscopic corrosion features of Galfan steel wires at different corrosion stages. 56,57 The corrosion behavior of the two steel wire types exhibits exponential growth patterns. While the corrosion coefficient for galvanized steel wire follows a normal distribution, the corrosion coefficient for Galfan steel wire conforms to a Cauchy distribution.…”

Effect of Coating on Stress Corrosion Performance of Bridge Cable Steel Wire

“…Compared with a traditional pure Zn coating, the ZnAl coating has better corrosion resistance and significantly lower costs [11]. Zhao et al [12] proved that the average service life of Galfan (Zn-5Al) steel wire under corrosion fatigue conditions was significantly higher than that of galvanized steel wire. In addition to ZnAl coatings, ZnAlMg coatings have also been extensively studied [13].…”