scholarly journals Hydrogen-Induced Cracking Caused by Galvanic Corrosion of Steel Weld in a Sour Environment

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5282
Author(s):  
Jin Sung Park ◽  
Jin Woo Lee ◽  
Sung Jin Kim

This study examined the hydrogen-induced cracking (HIC) caused by galvanic corrosion of an ASTM A516-65 steel weld in a wet sour environment using a combination of standard immersion corrosion test, electrochemical analyses, and morphological observation of corrosion damage. This study showed that the weld metal has lower open circuit potential, and higher anodic and cathodic reaction rates than the base metal. The preferential dissolution and much higher density of localized corrosion damage were observed in the weld metal of the welded steel. On the other hand, the presence of weldment can make steel more susceptible to HIC, specifically, in areas of the base metal but not in the weld metal or heat affected zone, which is in contrast to typical expectations based on metallurgical knowledge. This can be explained by galvanic corrosion interactions between the weldment and the base metal, acting as a small anode and a large cathode, respectively. This type of galvanic couple can provide large surface areas for infusing cathodically-reduced hydrogen on the base metal in wet sour environments, increasing the susceptibility of welded steel to HIC.

2014 ◽  
Vol 61 (6) ◽  
pp. 431-435 ◽  
Author(s):  
Rihan Omar Rihan

Purpose – This paper aims to report an experimental investigation of the galvanic corrosion that occurs between the base metal and the welds in X52 carbon steel petroleum pipelines when exposed in carbon dioxide (CO2)-containing saltwater at pH 4 at room temperature. The pipeline was fabricated by electric resistance welding (ERW). Design/methodology/approach – The experimental setup was a closed glass cell equipped with a silver/silver chloride (Ag/AgCl) reference electrode, two working electrodes (the weld metal and the parent steel specimens) and a gas bubbler. The corrosion potential and polarization resistance of the base metal and the weld were determined using electrochemical testing methods: potentiodynamic polarization scans and linear polarization resistance measurement. The galvanic currents of the base metal when coupled to the weld metal were measured using zero resistance ammetry. Findings – The weld metal was the anode of the couple for a very short time at the beginning of the experiment and then became the cathode until the end of the experiment. This indicates that electric resistance welded X52 steel pipe is a promising material to be operated in CO2-containing saltwater at pH 4 and 25°C because the weld area is cathodic to the parent metal, the value of the galvanic current is very low (in the order of nanoamps) and the area of the anode (i.e. the parent metal) is significantly larger than that of the cathode (weld metal). Research limitations/implications – Further experimental research could be performed to investigate the galvanic corrosion behavior between the parent metal and the weld area of X52 carbon steel petroleum pipelines in CO2-containing saltwater at different pH values, temperature and velocity. Practical implications – Electric resistance welded X52 steel pipe is a promising material for use with CO2-containing saltwater environments at pH 4 and 25°C. Originality/value – The new information presented in the paper is the galvanic corrosion behavior between the parent metal and the ERW weld metal of X52 carbon steel in CO2-containing solutions. The paper should be useful to researchers working in the field of oil industry corrosion.


2020 ◽  
Vol 64 (1) ◽  
pp. 23-28
Author(s):  
J. Hodač ◽  
Z. Fulín ◽  
P. Mareš ◽  
J. Veselá ◽  
O. Chocholatý

AbstractTo produce realistic test specimens with realistic flaws, it is necessary to develop appropriate procedure for corrosion flaw production. Tested specimens are made from steels commonly used in power plants, such as carbon steels, stainless steels and their dissimilar weldments. In this study, corrosion damage from NaCl water solution and NaCl water mist are compared. Specimens were tested with and without mechanical bending stress. The corrosion processes produced plane, pitting and galvanic corrosion. On dissimilar weldments galvanic corrosion was observed and resulted to the deepest corrosion damage. Deepest corrosion flaws were formed on welded samples. The corrosion rate was also affected by the solution flow in a contact with the specimens, which results in a corrosion-erosive wear. Produced flaws are suitable as natural crack initiators or as realistic corrosion flaws in test specimens.


Alloy Digest ◽  
2002 ◽  
Vol 51 (5) ◽  

Abstract Nimrod 617KS is an Inconel-type consumable with a nominal composition of nickel, 24% Cr,12% Co, and 9% Mo and is used to join UNS N06617 and Nicrofer 6023 to themselves. The alloy is designed for high-temperature service and is often used as the weld metal in dissimilar cases to ensure the weld is as strong as the base metal. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating and joining. Filing Code: Ni-583. Producer or source: Metrode Products Ltd.


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