Investigating molybdenum’s sulphur scavenging ability for MoS2 formation in preventing pitting corrosion of stainless steels

Abstract

The addition of Mo enhances pitting corrosion resistance in 304L stainless steel. However, there is no consensus on the underlying mechanism. One possible explanation is that molybdenum converts sulfide to stable MoS2. This study investigates the effect of MoS2 inclusion on the corrosion of 304L stainless steel by introducing both MnS and MoS2 using spark plasma sintering. The reduction of MoS2 to Mo is observed during the sintering process, contradicting the assumption that the sulfide inclusions can be stabilised by forming MoS2. Therefore, MoS2 formation cannot explain the improved corrosion resistance of 304L stainless steel with the addition of Mo.

Electrochemical properties of MnSe inclusions and improving the pitting corrosion resistance of stainless steel via Se microalloying

“…Pitting at MnS inclusions in stainless steels has been intensively studied, and anodic dissolution of MnS has been identified as the first step in the pit initiation process 20 – 31 . The dissolution of MnS exposes the bare surface of the steel matrix and produces S-species that are detrimental to the corrosion resistance of the steel matrix surrounding the inclusions, resulting in high pitting susceptibility near the inclusions in chloride solutions 32 – 34 .…”