An Experimental Study of the Corrosion Behavior of Nickel Tungsten Carbide in Some Water-Glycol Hydraulic Fluids for Subsea Applications

作者：Zheng Lei^*; Neville Anne; Gledhill Andrew; Johnston David

来源：Journal of Materials Engineering and Performance, 2010, 19(1): 90-98.

DOI：10.1007/s11665-009-9416-8

• corrosion
• hydraulic fluids
• nickel tungsten carbide
• stainless steel 316L

Corrosion failures of components in electro-hydraulic control systems can have serious consequences for the operation of an entire subsea oil recovery system, especially in water depths more than 150 m (Fleming, Meas. Control, 2000, 33(7), p 207-213). An acceptable reason for this is that seawater ingress can have a great effect on stainless steel 316L, the most commonly used material for the failed components of the direction control valves, since chloride irons destabilize the passive film [Malik et al., Corros. Sci., 1992, 33(11), p 1809-1827; Desalination, 1994, 97(1-3), p 189-197; Al-Malahy and Hodgkiess, Desalination, 2003, 158(1-3), p 35-42]. Other materials, claimed to be seawater tolerant, are starting to be used in this system. However, problems can still exist due to the complex factors relating to the corrosion process and how the environmental parameters affect the corrosion mechanisms. In this work, the corrosion behavior of a nickel tungsten carbide cermet, one of the proposed materials, is compared with stainless steel 316L, in four different water-glycol hydraulic fluids and 50% hydraulic fluid/50% seawater solutions using an electrochemical test methodology. Systematic fluid analysis, which includes GC-MS for organic components and ICP-MS analysis for ionic content, and surface analysis of the material are carried out to assess the corrosion mechanisms. Detailed conclusions are then made to summarize the advantages and disadvantages of nickel tungsten carbide being used in this system. The effects of each factor on the corrosion rates and mechanisms are discussed.

• 出版日期2010-2