The measured hydrogen content in parts of the material exceeded 40 ppm, more than an order of magnitude higher than what is normally expected in super duplex stainless steels. Previous work using slow strain rate testing3,4 had shown that these grades were susceptible to hydrogen embrittlement when exposed to cp s below 700mv sce. Hydrogeninduced stress cracking of swaged super duplex. Hydrogen induced stress cracking of swaged super duplex. Modelling of hydrogen diffusion and hydrogen induced cracking in supermartensitic and duplex stainless steels. However, the reported hydrogen diffusivity in duplex stainless steels dss at room temperature ranges from 1 to 5.
Request pdf investigation of hydrogen induced cracking in 2205 duplex stainless steel in wet h2s environments after isothermal treatment at 675, 750 and. Hisc is a term to refer to hydrogen stress cracking hsc of duplex and super duplex stainless steels dss and sdss, respectivelywhen exposed to hydrogen generated by cathodic protection. Hydrogen cracking of ferriticaustenitic stainless steel. A small number of duplex and superduplex stainless steel components have failed in subsea service due to hydrogen induced stress cracking hisc. The significance of these failures has led to research aimed at defining critical conditions for hisc, to allow confident design of components in future. Corrosionpedia what is hydrogeninduced cracking hic. Pdf hydrogen embrittlement of super duplex stainless. Super duplex stainless steel structures subjected to cathodic protection are prone to hydrogen embrittlement. The hydrogeninduced pitting corrosion mechanism in duplex stainless steel studied by currentsensing atomic force microscopy vladislav yakubov 1, 2 meichao lin 1.
The occurrence of cracks in offshore structures and pipelines can cause. Hydrogen cracking in duplex stainless steel weld metal american. When such hydrogen atoms combine again in very small metal voids to build molecules of hydrogen, they produce pressure within the cavity. Sigma phase precipitation and its influence on hydrogen induced. Studies of the fracture surfaces of hydrogen induced stress cracking, hisc, tested duplex stainless steels showed that hisc is a hydrogenenhanced localised. Pdf modelling of hydrogen diffusion and hydrogen induced.
Hydrogeninduced stress cracking of swaged super duplex stainless steel subsea components, corrosion 757. The programme sought to generate cracking data for sma welds, in 22%cr duplex stainless steel, for which the consumable hydrogen level had been determined using the vhe method. The brittle nature of the fracture surface, calcareous deposits on the ferrule and exposure to cathodic protection suggested hydrogen induced stress cracking hisc. The pressure created from the buildup can further elevate, which makes metal lose its tensile strength and ductility, reaching the point of cracking, or hic. Influence of hydrogen on corrosion and stress induced cracking of. Modelling of hydrogen diffusion and hydrogen induced.
The hydrogeninduced pitting corrosion mechanism in duplex. Hydrogen embrittlement in super duplex stainless steels. The results showed that the failure developed from a combination of factors, typical for hydrogeninduced stress cracking. Experience has shown that stainless steels can suffer from hydrogen induced stress cracking hisc under cathodic protection in seawater. Sigma phase precipitation and its influence on hydrogen induced cracking of duplex stainless steel base metal and weld metal. This chapter presents chemical composition, mechanical properties. Hydrogen induced cracking of subsea duplex stainless steel twi. Abstract a recent subsea failure of two subsea connectors made of uns s32760, a 25 wt% cr super duplex stainless steel, led to an extensive root cause failure analysis. Hydrogen induced stress cracking of duplex stainless steel. As a contribution to the interpretation and prediction of hydrogen induced cracking in welded. Duplex stainless steels are widely used in subsea petro. Hydrogen induced stress cracking in uns s32750 super. Modelling of hydrogen diffusion and hydrogen induced cracking in supermartensitic and duplex stainless steels 1. Cracking occurred in welds containing 83% ferrite and hydrogen levels of 11.
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