The three important parameters decisive for SCC initiation are temperature, aggressiveness
of medium (concentration of nitrite) and stress level. The dominating opinion in the
literature is that SCC proceeds at higher temperatures only, due to slow kinetics. In the
examined case, the failed fragment of the tube was cold, i.e. the ambient temperature
was certainly lower than the threshold value stated in the works [9,10] as a minimum
for SCC initiation.