|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Surface Engineering for Improved Corrosion Resistance
||Severe Plastic Deformation Surface Treatment on Corrosion and Environmental Cracking of Oilfield Alloys
||Ting Chen, Kripa Varanasi
|On-Site Speaker (Planned)
The effects of severe plastic deformation (SPD) surface treatment on corrosion and environmental cracking (EC) of super-alloy 718 and stainless-steel 71-4PH were investigated. Machine hammer peening and surface mechanical attrition (SMAT) techniques were applied to severe plastically deform alloys 718 and 17-4 PH respectively. Post SPD, three distinct layers near the peened surface in alloy 718 were observed. On the top was a Cr-enriched oxide film. Second was a thin layer with γ’/γ’’ precipitates, and the one nearest to the bulk material was a visible plastically deformed ultra fine-grained layer rich in slip bands. To assess EC susceptibility of 17-4PH, C rings stressed to 90% of its yield-strength were exposed to HPHT sour environment having significantly more hydrogen sulphide than its MR0175 recommended limit. In contrast to untreated alloy, the SMAT 17-4PH specimens did not suffer EC due to compressive residual stresses introduced by SPD offsetting the tensile component due to stress loading. The influence of SMAT on corrosion behavior of light metals will also be reviewed.
||Planned: Supplemental Proceedings volume