J. V. Kenkel

Bio: J. V. Kenkel is an academic researcher. The author has contributed to research in topics: Cathodic protection & Galvanic corrosion. The author has an hindex of 1, co-authored 1 publications receiving 51 citations.

Galvanic Corrosion of Al Alloys I. Effect of Dissimilar Metal

Abstract: Galvanic interaction between the Al alloys 1100, 2024, 2219, 6061, 7075, and Ag, Cu, Ni, Sn, Cd, Zn, the stainless steels 301, 304L, 347, A286, PH13-8Mo, Steel 4130, Inconel 718, Haynes 188 and Ti-6AI-4V has been studied in air saturated 3.5% NaCl by weight loss measurements and continuous monitoring of the galvanic current in 24 hour tests. Results show that the potential difference of uncoupled dissimilar metals, while in most cases accurately predicting the direction of current flow, is a poor indicator of the extent (rate) of galvanic corrosion of coupled dissimilar materials. The values of the average galvanic current density agree well with the increase of dissolution rates due to galvanic coupling. In general, galvanic corrosion of Al alloys coupled to dissimilar metals decreases in the order Ag > Cu > steel 4130 ≫ stainless steels ≈ Ni > Inconel 718 ≫ Ti-6AI-4V ≈ Haynes 188 >Sn > Cd. Coupling to zinc does not result in cathodic protection for all Al alloys studied, but can lead to increas...

Electrochemical monitoring of atmospheric corrosion phenomena

Abstract: An atmospheric corrosion monitor (ACM) which consists of CuZn or Cu/steel couples, has been used to study various aspects of atmospheric corrosion. Calibration of ACM's is carried out under 1 ml of distilled water. Measurements under 10−510−1N KCl show that the conductivity of the electrolyte is not an important parameter in determining the amount of current flow. A detailed study was related to the effect of salt particles on atmospheric corrosion. While no current flow and no corrosion occurred on clean surfaces up to r.h. ≈ 95%, large increases of the galvanic current were observed when salt particles were placed on the ACM surface provided that the relative humidity in the test cell was higher than the r.h. value of a saturated solution of the salt particle applied. The ACM has also been used to monitor changes in the composition of gaseous atmospheres (air, N2, N2 plus SO2). Outdoor exposure of the CuZn and Cu/steel ACM suggests that this instrument can be used not only to monitor time-of-wetness, but also the corrosivity of a test environment.

Galvanic corrosion of metal/ceramic coupling

Abstract: The galvanic corrosion risk of metal/SiC-based ceramic coupling in 3.5 wt% NaCl aqueous solution is investigated. Electrochemical measurements as linear sweep voltammetry and galvanic corrosion tests according to DIN-50919 were used. The results clearly show that the resistivity of the SiC-based ceramic plays the key role in the understanding of galvanic corrosion between metal and ceramic. In all cases the ceramic represents the cathodic site of the coupling. The corrosion rate is dominated by the electrical resistance of the ceramic.

Electrochemical behaviour of graphite-epoxy composite materials (GECM) in aqueous salt solutions

Abstract: The electrochemical behaviour of graphite-epoxy composite materials (GECM) in neutral 3.5% aqueous solutions of NaCl has been investigated. Two types of composite and pure graphite have been studied. The composite material shows a high value of electrode potential ranging between −40 and +70 mV versus SCE, and behaves as cathode when coupled to alloys.

Galvanic corrosion associated with SM 80SS steel and Ni-based alloy G3 couples in NaCl solution

Abstract: Potentiodynamic polarization and electrochemical impedance measurements were used to examine the effects of area ratio Sc/Sa and temperature on the galvanic corrosion behavior between SM 80SS steel and Ni-based alloy G3 exposed to CO2 and NaCl environment. It mainly comprised of the electrochemical characterization such as the self-corrosion potential, the galvanic current and Nyquist plots and so on. Weight loss method was utilized to investigate the corrosion rate of the galvanic couples in high temperature and high-pressure autoclave. After the tests, the surface morphologies of the samples were detected by SEM. In addition, pitting corrosion behavior of anodic material caused by galvanic corrosion was also investigated. The quadratic polynomials corresponded to similar parabolas were fitted to compare the curves of Ig vs. Sc/Sa and CRa vs. Sc/Sa. The results indicate that temperature and Sc/Sa have important effects on the couples of the galvanic corrosion.