TITLE:
The Influence of Ceramic Coating on Fatigue Crack Growth Behaviour of X17CrNi15-2 Stainless Steel
AUTHORS:
Ran Li, Wenshu Wei, Shoubin Li, Rui Zhao, Hao Liu, Jiankai Zhang, Jian Ye, Huigang Wu, Yao Xu, Fei Xiao, Mengyu Wu, Dalong Wang, Jingbin Chen, Wei Wang, Na Gao, Rongming Chen
KEYWORDS:
Fatigue Crack Growth, SEN B3 Precracked Specimen, X17CrNi15-2, Ceramic Coating Deposition Surface Treatment, Corrosion Resistance
JOURNAL NAME:
Engineering,
Vol.12 No.2,
February
28,
2020
ABSTRACT: Fatigue crack growth tests were carried out on the SEN B3 precracked specimens, with dimensions in accordance with ISO 12108 requirements. The specimens were made of martensitic stainless steel, X17CrNi15-2, and some of them were modified by the ceramic coating deposition surface treatment. The effects of ceramic coating, on the fatigue crack growth behaviour of hollow shaft specimens, were experimentally investigated. Fatigue crack growth rates, da/dN, were characterised, using the power law relationship between da/dN (in mm/cycle) and the stress intensity factor range, ΔK (in MPa∙m0.5). The two constants of the correlation are 7.9768 × 10−9 and 2.8107 for the parent material, and those for the coated material are 2.4391 × 10−9 and 3.1990, respectively. Microstructural analyses were carried out on the tested specimens, which shows that the maximum hardness of the ceramic coating is higher than that of substrate by a factor of ~3.2. The dimple fracture dominates the final fracture mechanism for the parent material, and the combination of fatigue, ductile fracture and cleavage dominates the final fracture mechanism for the coated material, based on the SEM analyses. EDS tests’ results reveal that the parent material specimen shows higher levels of C at matrix regions along with Fe- and O-rich regions, compared with the coated material specimen.