Hydrogen stress cracking

Most refiners employ continuous water wash as the principal mei of controlling corrosion and hydrogen blistering. The best sourc water is either steam condensate or well-stripped water from a water stripper. A number of refiners use ammonium polysulfat neutralize hydrogen cyanide and to control hydrogen stress crack... 

GR-5.9 PERMANENT FIELD REPAIR OF HYDROGEN STRESS CRACKING IN HARD SPOTS AND STRESS CORROSION CRACKING... 

Unless heavily cold worked, the austenitic stainless steels are resistant to hydrogen stress cracking such as that caused by hydrogen sulfide. They are also resistant to hydrogen embrittlement caused by phenomena other than cathodic charging. If sensitized, austenitic stainless steels can also be susceptible to intergranular corrosion. 

With the desired microstructure, these alloys are resistant to hydrogen stress cracking and much more resistant to chloride stress corrosion cracking than are the austenitic stainless steels. (The threshold temperature for chloride stress corrosion cracking of duplex alloys in neutral pH aqueous chlorides is about 300°F [150°C].) The chloride stress corrosion cracking resistance of the duplex alloys is similar to that of superaustenitic alloys such as Alloy AL-6XN. Because they contain about 50% ferrite, the duplex stainless steels are more susceptible to hydrogen embrittlement. 

Identification of the hydrogen-stress cracking mechanism is more recent, and much less is known about it. To date, research pinpointed has several factors contributing to this form of hydrogen deterioration. Here are a few. 

Hydrogen-environment embrittlement (HEE) Hydrogen stress cracking (HSC) Loss in tensile ductility... 

Hydrogen cracking, also called hydrogen stress cracking... 

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