the stress‐corrosion cracking of mild steel in coal gas liquors

A field survey and laboratory experiments using synthetic liquors, have indicated the chemical conditions under which cracking is likely to be observed in coal‐gas cleaning plant. The incidence of failure in the various items of a typical plant can be related to the chances of these conditions arising at that point in the cleaning train. The conditions are not particularly critical with respect to composition. It is tentatively suggested that cyanides permit the grain boundaries of the mild steel to be corroded and cracks to propagate, by forming soluble complexes with iron in alkaline solutions.