Effect of non-conventional heat treatment of API X60 pipeline steel on corrosion resistance and stress corrosion cracking susceptibility
Anti-Corrosion Methods and Materials
ISSN: 0003-5599
Article publication date: 8 January 2019
Issue publication date: 25 April 2019
Abstract
Purpose
The purpose of this paper is to study the effect of heat treatment (HT) applied to an API X60 steel in corrosion resistance and stress corrosion cracking (SCC) susceptibility through slow strain rate tests (SSRT) in NS4 solution and congenital water (CW) to assess external and internal SCC, respectively.
Design/methodology/approach
API X60 steel was heat treated at a temperature of 1,200°C for 30 min followed by water quenching. Specimens from this steel were machined according to NACE TM 198. SSRT were performed in a constant extension rate tests (CERT) machine at room temperature at a strain rate of 1 × 10–6 s–1. For this purpose, a glass cell was used. Corrosion behavior was evaluated through polarization curves (PCs).
Findings
The SCC index obtained from SSRT indicates that the steel heat treated could be susceptible to SCC in CW and NS4 solution; the mechanism of SCC was hydrogen embrittlement. Thus, CW may promote the SCC phenomenon in pipelines. HT improves the steel corrosion resistance. Higher corrosion rate (CR) was observed when the steel is exposed to CW. The corrosion process in X60 steel shows that the oxidation reaction in the anodic branch corresponds to an activation process, and the cathode branches reveal a diffusion process.
Originality/value
The purpose of the heat treatment applied to X60 steel was to generate a microstructure of acicular ferrite to improve the corrosion resistance and SCC behavior.
Keywords
Acknowledgements
The authors gratefully acknowledge the financial support from the National Council of Science and Technology (CONACyT) under Grant 10003. Also, the authors would like to thank Universidad Michoacana de San Nicolás de Hidalgo (UMSNH) and Instituto Mexicano del Petróleo (IMP) for the support received during experimental development.
Citation
Jacobo, L.R., Garcia, R., Lopez, V.H. and Contreras, A. (2019), "Effect of non-conventional heat treatment of API X60 pipeline steel on corrosion resistance and stress corrosion cracking susceptibility", Anti-Corrosion Methods and Materials, Vol. 66 No. 3, pp. 274-285. https://doi.org/10.1108/ACMM-08-2018-1981
Publisher
:Emerald Publishing Limited
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