Corrosion fatigue crack growth behavior of a structurally gradient steel for high-speed railway axles. (28th March 2023)

• Record Type: Journal Article
• Authors: Ao, Ni; Zhang, Han; Xu, Huihui; Wu, Shengchuan; Liu, Dong; Xu, Pingguang; Su, Yuhua; Kan, Qianhua; Kang, Guozheng
• Is Part Of: Engineering fracture mechanics. Volume 281(2023)
• Publication Date: 2023-03-28
• Subjects: Corrosion fatigue crack propagation -- Gradient microstructure -- Surface defect -- Corrosion behavior; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2023.109166
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: Effect of corrosive medium on FCG behaviors in a structurally gradient steel with different pre-crack depths is clarified. Relationship between pre-crack depth and FCG/CFCG rates is revealed. Compared with corrosion, fatigue loading plays a major role in CFCG rate at a frequency of 5 Hz. X-ray μCT results verified a retardation effect of anodic dissolution on CFCG rate. Abstract: Considering the complex service environments that high speed railway axles are subjected to, the fatigue crack growth (FCG) behavior of a structurally gradient axle steel with different pre-crack depths both in air and a corrosive medium was investigated at a frequency of 5 Hz. The results indicated that in the high Δ K region, the FCG rate was dramatically accelerated by corrosion but the gap narrows as Δ K decreased. The accelerated corrosion FCG rate was a comprehensive result of the acceleration effect of the anodic dissolution, hydrogen-enhanced localized plasticity and the retardation effect of corrosion-induced crack-tip blunting. Despite the fact that the corrosion resistance gradually decreased as the pre-crack depth increased, the FCG rate in the corrosive medium gradually decreased. This was because fatigue loading played a more important role than corrosion in accelerating the corrosion FCG rate.