Materials Selection for Use in Concentrated Hydrochloric Acid

Abstract

Hydrochloric acid (HCl) is an important mineral acid with many uses, including the pickling of steel, acid treatment of oil wells, and chemical cleaning and processing. This acid is extremely corrosive and its aggressiveness can change drastically depending on its concentration, the temperature, and contamination by oxidizing impurities. One of the most commonly encountered oxidizing impurities is the ferric ion. In general, stainless steels cannot tolerate aggressive HCl solutions, hence the need to use corrosion resistant nickel-based alloys. A part of this study focused on the role of alloying elements on the corrosion performance of commercial nickelbased alloys UNS N10276, UNS N06022, UNS N06200, UNS N07022, UNS N10362, UNS N10675, UNS N06059, and UNS N06625, in HCl solutions, with and without the presence of oxidizing impurities (ferric ions). Aggressive HCl solutions can also be used to simulate the critical crevice solution. Therefore, another aspect of this research is to investigate the role of alloying elements in nickel-based alloys on the inhibition of crevice corrosion. In the present study, various standard corrosion test methodologies, conservative electrochemical techniques, and a range of surface analytical tools have been utilized.

Performance of Corrosion-Resistant Alloys in Concentrated Acids

“…The results are in consensus with the weight loss data [4]. Recently, Mishra et al [10] demonstrated the role of alloying elements on the corrosion performance of various Ni-Cr-Mo (W) alloys in aggressive chloride environment which can also be simulated as a critical crevice solution.…”

Corrosion Study of Base Material and Welds of a Ni–Cr–Mo–W Alloy

“…For applications in HF and H 2 SO 4 , Fe-and Ni-based alloys containing Cu exhibit an enhanced corrosion resistance performance [7][8][9][10][11][12]. In Crrich alloys, Cr primarily forms a passive film of Cr 2 O 3 on the surface, thereby imparting better passivation properties [6,[13][14][15][16]. Molybdenum and tungsten are known to inhibit localized corrosion by oxide formation within the pit, thereby retarding the pit/crevice growth [6,[13][14][15][16][17][18][19].…”

“…A recent study [6,13] performed on a wide range of corrosion-resistant Ni-Cr-Mo and Ni-Cr-Mo-W alloys in various acidic solutions suggested that Mo (or Mo and W) forms a protective oxide in low pH-reducing acids (like HCl, H 2 SO 4 and H 3 PO 4 ), responsible for an enhanced corrosion resistance performance in Mo-rich alloys, Available online at http://link.springer.com/journal/40195 & Ajit Mishra ajitosu@gmail.com…”

“…In order to have an excellent localized corrosion resistance, an alloy must contain high amounts of Cr as well as Mo (or Mo and W). These studies correlated the role of alloying elements to the performance of alloys in various concentrated acidic solutions; however, the materials chosen for the study [6,13] was primarily restricted to Ni-Cr-Mo and Ni-Cr-Mo-W alloys. Despite a higher corrosion resistance and better mechanical properties of corrosion-resistant Nibased alloys compared to Fe-based alloys (like stainless steel), the former are not a preferred choice of materials because of its high cost, unless the environments are very aggressive.…”

Green synthesis and anticorrosion effect of Allium cepa peels extract-silver nanoparticles composite in simulated oilfield pickling solution

“…Also called muriatic acid, it is used for cleaning surfaces of various metals and alloys, including steel, especially to remove scales, rust and mineral deposits. In general, HCl used is for chemical cleaning/pickling of steel, reduction of ores and processing, industrial preparation of chlorine and chlorides, acid treatment of oil and gas wells and in food processing [1]. However, HCl is known for its high corrosivity, and depending on temperature under which operation is carried out and the concentration of the acid used, it can rather be aggressive to and corrode the surfaces meant to be cleaned.…”