In previous works, extensive desulphurisation, including shape control and low hardness in segregation zones, were pointed out as effective ways for increasing resistance to hydrogen induced cracking (HIC) in steels exposed to wet H2S environment. In this study, the behaviour of eight plates was evaluated by immersing samples in H2S-saturated NACE solution (5% NaCl plus 0.5% acetic acid solution saturated with H2S, pH 3-3.5). HIC susceptibility was assessed by an ultrasonic method and correlated with the elongated MnS inclusion distribution. The results allow us to remark that an extremely low suphur level is not necessary to reach good HIC resistance, provided that no hard bands are present in the steel. Under this condition, a relationship to calculate the minimum average sulphide length which provides low HIC susceptibility was found. The microstructure was observed by optical and scanning electron microscopy (SEM). From the steelmaker point of view, is important to note that it is not necessary to reach costly extra low values of sulphur in order to obtain a good HIC resistance in sour environments.
Influence of sulphur content and inclusion distribution on the hydrogen induced blister cracking in pressure vessel and pipeline steels
Einfluss des Schwefelgehaltes und der Verteilung der Einschlüsse auf die wasserstoffinduzierte Rissbildung in Druckkessel und Rohrstählen
Corrosion Science ; 43 , 2 ; 325-339
2001
15 Seiten, 8 Bilder, 5 Tabellen, 11 Quellen
Article (Journal)
English
Rohrleitung , Druckkessel , Schwefel , Verunreinigung , Einschluss , Sulfideinschluss , Mangansulfid , Rissbildung , Rissempfindlichkeit , Wasserstoffversprödung , Korrosionsversuch , saures Medium , Schwefelwasserstoff , Essigsäure , Natriumchlorid , Mikrogefüge , Mikrohärte , Rasterelektronenmikroskopie , Korrosionsbeständigkeit , unlegierter Stahl , Wasserstoff , chemische Industrie , Erdölindustrie , Messverfahren mit Ultraschall
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