This paper will critically review the current philosophies described in ISO and NACE anti-corrosive performance test standards, taking into consideration correlation with natural exposure, track record, validity of "acceptance" or "pre-qualification criteria", dry film thickness and suggested areas for improvement.
UNS N04400 cladding on steel valves can corrode during marine service. The uniform corrosion rate of an EN coating in artificial seawater was measured by electrochemical impedance spectroscopy and was found to be less than that for N04400. The main conclusion is that an EN coating could be a viable solution to repair N04400-clad valves in-situ.
Performance of formulations of antifouling coatings to protect carbon steel from effects of microbiologically influenced corrosion (MIC) and marine biofouling in a tropical harbor seawater was assessed by field and laboratory experiments. • Scanning electron microscopy (SEM). • Energy dispersive spectroscopy (EDS). • X-ray diffraction (XRD). • Seawater immersion.
It has been important for the oil industry to establish reliable test method(s) for qualification and safe utilization of subsea pipelines and components made from stainless steels. This paper describes a method that has been developed through a JIP executed with support from leading oil companies and meterial suppliers.p
Modern high performance paint systems are so durable that when exposed to natural weathering they may show only slight signs of deterioration. This means that new coatings being marketed have limited track records. Which creates an increased reliance on accelerated laboratory testing to evaluate performance.
How calcareous deposits formation in seawater influences the performance of a galvanic cathodic protection (CP) system in seawater. Coupling current measured. A resistance set between the cathode and the anode simulated circuit resistance of CP. Steel cathode potential over immersion time. Calcareous deposits analyzed by X-Ray Diffraction.
Field experience was studied to identify the best solutions to Localized corrosion of 316 stainless steel instrument and chemical injection tubing in marine environment. Laboratory tests and exposure in marine environment of samples have been used to evaluate possible alternative materials and protective chemicals.
Aluminium alloy sacrificial anodes are often used to protect marine structures due to their high electrochemical properties. Anodes are often immersed in seawater when the tank is ballasted and dry with the tank empty. We study the properties of an Al-Zn-In-Cd alloy anode with cyclic immersion in seawater in the laboratory.
Experience has shown that stainless steels can suffer from Hydrogen Induced Stress Cracking (HISC) under cathodic protection in seawater. This paper presents results from a test program examining the HISC susceptibility of 25% Cr super duplex stainless steel (UNS S32750) at temperatures up to 1500C.
Superduplex stainless steels have been used in seawater systems since 1986 as castings and since 1990 as wrought product. The present paper describes some of the service environments commonly in use and the conditions that give rise to specific operating potentials. The limits of use under these conditions are described utilizing both laboratory and service experience.