Corrosion inhibitors are useful to mitigate corrosion of metal/alloy components. However, traditional corrosion inhibitors are toxic and need to be replaced by greener alternatives. Efficient screening models are required to find molecules with desired properties from millions of molecules available in public domain. To make these models, database of experimental inhibition efficiency of molecules is essential. In this work, we have developed a computational framework to accelerate the discovery of new corrosion inhibitors. We have used machine learning based algorithms to predict corrosion inhibition efficiency of organic molecules for steel in hydrochloric acid by using structural information of the molecules along with experimental conditions. Our multitask learning based neural network architecture was able to outperform traditional machine learning algorithms such as random forest, lasso and ridge regression. We have also created the largest dataset for predictive modelling of corrosion inhibitors for steel. Besides, we have also used the model to screen molecules from the ZINC15 dataset and found potential inhibitors with high inhibition efficiency.
Corrosion of metallic structures is a ubiquitous problem in industries such as power generation, oil and gas, pulp and paper, metals processing etc. which also results in significant financial losses . According to the National Association of Corrosion Engineers (NACE) International report, the global cost of corrosion was ∼ 2.5 trillion USD in 2013 - close to 3.4 percent GDP of the entire world . The use of corrosion inhibitors is one of the most effective and economical ways to mitigate corrosion of metal and alloy components [3,4]. Corrosion inhibitors are substances that are added in small quantities in corrosive media to protect metal and alloy components from corrosion . Organic corrosion inhibitors are typically surfactant-type compounds comprising mainly of two parts: (a) a hydrophilic head group containing heteroatoms such as O, N and S and (b) a hydrophobic tail group comprising hydrocarbon groups [6-8]. These compounds form an effective barrier layer on the metal or alloy surface thereby stopping the transport of ions and corrosive species [3,9], thus, inhibiting corrosion. However, most of these inhibitors and their formulations are toxic in nature, and many organizations such as the OSPAR Commission (Oslo/Paris commission for protection of the marine environment of north-east Atlantic) have restricted their use . Therefore, there is a need to develop novel and effective corrosion inhibitors that meet environmental regulations.