High-temperature inhibitors of stainless steel corrosion in hydrochloric acid solutions

Abstract

The corrosion of chromium-nickel steel 08Kh18N10T in 2 M HCl has been studied in a broad temperature range, t = 0-160°C. Under these conditions, the metal corrosion is enhanced with an increase in temperature to reach 5.0 kg/(m 2 ·h) at 160°C. It has been shown that the IFKhAN-92 inhibitor (a substituted triazole) and its formulation with urotropine in a molar ratio of 1:4 protect this steel in 2 M HCl at temperatures up to 120°C, inclusive. The three-component mixture of IFKhAN-92, KI and urotropine (1:1:4) is more promising in this respect, as it efficiently inhibits corrosion at temperatures up to 160°C and allows the protective effect to be maintained for at least 8 h. This formulation also reliably protects low-carbon steel 20 in 2 M HCl at temperatures up to 160°C, inclusive.Key words: high-temperature acid corrosion, corrosion inhibitors, stainless steel, triazoles. Received: March 17, 2017. Published: April 28, 2017. doi: 10.17675/2305-6894-2017 Acid treatment in the bottom-hole zone of oil-bearing and gas-bearing formations has been used for over 100 years and still remains the main approach for intensifying the production of liquid and gaseous hydrocarbons [1,2]. Hydrochloric acid treatment of these formations with bottom-hole temperature (t) up to 80°C generally shows no technology-related problems in the inhibitory protection of steel parts of underground equipment of wells and special equipment used in this operation from acid corrosion. At higher temperatures, the vast majority of inhibitors lose efficiency in metal protection from acid corrosion, which makes it impossible to use them in this operation [3]. Development of corrosion inhibitors capable of steel protection in HCl solutions at t  80C, the so-called high-temperature inhibitors, is performed in two ways: a search for new individual compounds that hinder

Nitrogen-containing six-membered heterocyclic compounds as corrosion inhibitors for metals in solutions of mineral acids – A review

“…As we have shown previously [137][138][139], the fact that triazoles form such layers on steel surface allows the highest protective effects to be reached. The fact that triazoles form protective layers on metal surfaces makes it possible to use them for the protection of mild and chromium-nickel steels even under high-temperature acid corrosion conditions [140][141][142].…”

Protection of low-carbon steel in solutions of mineral acids by nitrogen-containing pharmaceutical agents of triphenylmethane series

“…It is the basis or a component of many inhibitors, including those produced on industrial scale [4]. It has recently been shown [5,6] that multicomponent inhibitor formulations containing urotropine can slow down the corrosion of low-carbon and chromium-nickel steels in HCl and H 2 SO 4 solutions under hightemperature corrosion conditions (up to 200C).…”