Sulfide stress cracking

The historical development of the understanding of sulfide stress cracking (SSC) is presented and the possible mechanisms and the significant parameters are discussed. Basic differences between sour service and sour corrosion are highlighted and the carbon dioxide to hydrogen sulfide ratios used to define sour corrosion are mentioned. The effect of corrosion on the initiation and propagation of SSC is considered. The procedures for testing the resistance of a material to SSC are outlined and a review given of the practices taken to avoid cracking. The interrelationship of SSC with hydrogen-induced cracking and stress-orientated hydrogen induced cracking are briefly discussed. Areas of ignorance, grey areas, and possible lines of research are listed.