Lower pH and lower applied redox potential facilitate the evolution and the enrichment of hydrogen during the process of SCC, thus increasing the SCC intensity.
* Certain austenitic stainless steels and aluminium alloys crack in the presence of chlorides. This limits the usefulness of austenitic stainless steel for containing water with higher than a few parts per million content of chlorides at temperatures above ;
* mild steel cracks in the presence of alkali (e.g. boiler cracking and caustic stress corrosion cracking) and nitrates;
* copper alloys crack in ammoniacal solutions (season cracking);
* high-tensile steels have been known to crack in an unexpectedly brittle manner in a whole variety of aqueous environments, especially when chlorides are present.
With the possible exception of the latter, which is a special example of hydrogen cracking, all the others display the phenomenon of subcritical crack growth, i.e. small surface flaws propagate (usually smoothly) under conditions where fracture mechanics predicts that failure should not occur. That is, in the presence of a corrodent, cracks develop and propagate well below critical stress intensity factor (). The subcritical value of the stress intensity, designated as , may be less than 1% of .