Electrolytic-plasma removal of two-layer SDP1+VSDP20 coating from the surface of parts made of EP866-Sh steel

Abstract

This article presents the results of selecting an electrolyte for removing a 2-layer vacuum plasma coating SDP1+VSDP20 from a substrate made of EP866-Sh steel using the method of electrolytic plasma polishing (EPP). The article shows that the SDP1+VSDP20 coating has a complex chemical composition that varies with depth, resulting in problems with its removal using various chemical and electrochemical methods. As a result of the study, it was established that this coating can be removed by the EPP method by adding substances to the electrolyte that form complex compounds that are easily soluble in water with metal ions included in the composition of the coating and substrate. It has been shown that the addition of ligands in an amount of 0.5–2 % can ensure uniform removal of the SDP1+VSDP20 coating without damaging the substrate material.