51314-4147-Corrosion Resistance Properties of Plasma Deposited CRA Coatings on 4140 Carbon Steel

Available for download

Product Number: 51314-4147-SG

ISBN: 4147 2014 CP

Author: Elizabeth Trillo

Publication Date: 2014

Member Price: $0.00

Non Member Price: $20.00

Price: $20.00

Qty:

In oil and gas industry key components made of carbon steels expose to severe corrosion environments in which high partial pressures of H2S CO2 and Cl exist. This study explores the possibility if applying a Corrosion Resistant Alloy (CRA) coating on carbon steels in order to protect them. Hastelloy C-276 was used as the source material and deposited on 4140 carbon steel coupons using a Plasma Enhanced Magnetron Sputter (PEMS) process developed at Southwest Research Institute (SwRI). The coating thickness was varied from 0.1 to 11 µm. The coated coupons along with uncoated ones were then tested under a NACE MR0175 / ISO 15156 Level V condition. The exposure included a test solution with 91000 ppm Cl (using NaCl) equilibrated with 100 psi H2S / 200 psi CO2 at 302 F for 30 days. Preliminary results indicate that the baseline carbon steel samples (with no C-276 coating) had a corrosion rate of 15.44 mpy (0.386 mmpy) after exposure and many pits were observed on the sample surface. The maximum pit depth was 0.71 mils. In contrast under the optimal coating conditions the C-276 coated samples showed the mass loss corrosion rates of <0.5 mpy (0.0125 mmpy) and exhibited no pitting. In this paper the PEMS process will be discussed and the detailed corrosion test conditions and the corrosion data will be presented. Practical application examples will be also given in the paper.