Hydrogen induced stress cracking resistance

Hic test, hydrogen induced cracking test, step wise cracking. Sohic can also propagate from blistering caused by hydrogen induced cracking hic. Hydrogen induced cracking failures of sour gas processing equipment and transmission pipelines have been reported at facilities in libya, saudi arabia and other middleeastern plants. Hydrogen induced stress corrosion cracking hscc resistance and mode of fracture in various low and high strength steels yield strength 120 to 960 mpa and containing different levels of phosphorus content were studied using constant extension rate test method in various acid media viz. Ferriticaustenitic duplex stainless steels should be regarded as potentially susceptible to hydrogen induced stress cracking, independent of smys typically 400 to 550 mpa or specified maximum hardness.

Hydrogen induced cracking of subsea duplex stainless steel. Stress corrosion cracking facts and how to reduce the. This term should not be confused with stress corrosion cracking scs, since this is anodic in nature. Susceptibility to hydrogeninduced cracking of api 5l b and x52ms lowcarbon steels in nace 177a, 177b, and 284b solutions has been investigated by the present work. Vargas pm, wastberg s and woollin p, stress based design guidelines for hydrogen induced stress cracking hisc avoidance in duplex materials, proc conf omae 200979504. Hydrogen induced cracking hic in steel is a risk problem when steels are charged with hydrogen in service as in various hydrogen sulfide environments like sour oil and gas wells and some power plants. There is a growing acceptance of the term scc to co\er both mechanisms. The blistering damage tends to form parallel to the surface and to the direction of hoop stress. Hydrogen induced stress cracking hisc resistance and improvement. Metallurgical factors in stress corrosion cracking scc and. Stress corrosion cracking and hydrogen embrittlement of high.

Hic test, hydrogen induced cracking test, step wise. Hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms. The hydrogeninduced pitting corrosion mechanism in duplex. Hic usually occurs due to the effects of aqueous hydrogen charging of steel in wet h2s refinery process environments. Hydrogen embrittlement he also known as hydrogen assisted cracking hac and hydrogen induced cracking hic, describes the embrittling of metal after being exposed to hydrogen.

Assessment of the hydrogen induced stress cracking. The role of hydrogen in the mechanism of stress corrosion cracking has been known since the 1970s so that preventative measures have since been introduced. Scc is highly chemically specific in that certain alloys are likely to undergo scc only when exposed to a small number of chemical environments. Pdf the resistance toward hydrogeninduced stress cracking hisc of forged and hot isostoiically pressed hip super duplex stainless steel. Hydrogen embrittlement he also known as hydrogen assisted cracking hac and hydrogeninduced cracking hic. Hydrogeninduced cracking an overview sciencedirect topics. Some of the examples are resistance to hydrogen sulphide h2s cracking such as sulphide stress cracking ssc, stress oriented hydrogen induced cracking sohic, hydrogen induced cracking hic, step wise cracking swc, soft zone cracking szc etc.

Duplex stainless steels have desirable properties with regard to resistance to the environment, as well as adequate strength and toughness. Abstract a recent subsea failure of two subsea connectors made of uns s32760, a 25 wt% cr super duplex. The diffusion coefficient for the hydrogen atom in the spv50q steel was determined at 2560 c and the activation energy for diffusion was 24. Corrosion products were characterized by scanning electron microscopy and xray dispersive energy spectrometry, which were. Hydrogen induced cracking steel features, applications. Hydrogen blistering a special case of hydrogen damage is known as hydrogen blistering. Hydrogen induced stress cracking of superduplex steels. Thus, the three causative factors promoting hydrogeninduced stress cracking, namely, a susceptible. Sulfide stress cracking ssc is a type of hydrogen cracking which presents a cathodic embrittlement mechanism. Ihac and heac are distinguished by the source of the offending h supplied to the crack tip fracture process zone fpz, but otherwise share common aspects. Hydrogeninduced cracking hic in steel is a risk problem when steels are charged with hydrogen in service as in various hydrogen sulfide environments like sour oil and gas wells and some power plants. Also high strength structural steels which are welded are exposed to a certain hydrogen pickup which means a risk at fracture and blistering. Stress oriented hydrogen induced cracking sohic stress orientated hydrogen induced cracking occurs in the area of grain enlargement in weld heat affected zones. The paper looks at the problem of hydrogen cracking both in general fabrication and with particular reference to.

Hydrogen induced crack resistant hic steel plate brown mcfarlane offers the widest range of carbon and stainless steel plate, available exstock. Stress corrosion cracking scc is characterized by cracks propagating either transgranularly or intergranularly along grain boundaries. A corrosive medium especially chloridebearing or hydrogen sulphide h 2 s media. It can lead to unexpected sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature. The root cause of these failures was identified to be hydrogen induced stress cracking, hisc, where the hydrogen source was the. Specificationsgrades asmeastm saa 516 grades 606570. Hydrogen cracking its causes, costs and future occurrence twi.

Effect of microstructure on hydrogeninduced cracking of. A model has been developed which simulates the deformation of single crystal austenitic stainless steels and captures the effects of hydrogen on stress corrosion cracking. Aug 01, 2019 hydrogen induced stress cracking of swaged super duplex stainless steel subsea components, corrosion 757. Hydrogen induced craking hic, also referred to as hydrogen stress cracking or static fatigue, is a typical form of hydrogen embrittlement. Hydrogen cracking its causes, costs and future occurrence. Resistance toward hydrogeninduced stress cracking of hot. Hydrogen induced stress cracking hisc and dnvrpf112.

Hydrogeninduced stress cracking of swaged super duplex. Hydrogen induced stress cracking hisc and dnvrpf112 and increase the risk for brittle fracture of the material. The following work has examined the effect of heat treatment, production method and cold working cw on the hydrogen induced stress cracking hisc susceptibility of inconel 625 uns n06625. Hydrogen stress cracking is a form of hydrogen embrittlement that occurs when corrosion from acids like wet hydrogen sulfide and hydrofluoric acid cause atomic hydrogen to penetrate hardened or higher strength steels and cause stress cracking. The initial cracking problem was recognised during subsea hydro testing, prior to start up, after 6 months underwater, when pressure could not be maintained. Hydrogen induced cracking hic is a common form of wet h2s cracking caused by the blistering of a metal due to a high concentration of hydrogen. The term environmental stress cracking1 failures is also used sometimes. Sulfide stress cracking mostly occurs in very highly acidic environments. However, bp and shell experience some serious cracking of duplex steel in the mid 90ties and in beginning of the century. Hydrogen induced stress cracking civilweb spreadsheets.

Important factors on the failure of pipeline steels with. Previous studies showed that sulphide stress cracking, hydrogen induced cracking hic and stress corrosion cracking. Pdf hydrogeninduced stress cracking of swaged super. 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. Stress corrosion cracking and hydrogen embrittlement of. Hydrogen induced stress cracking hisc resistance and. Stress corrosion cracking scc is the growth of crack formation in a corrosive environment. It involves atomic hydrogen, which is the smallest atom, that diffuses into a metallic structure. More often, fracture occurs at sustained loads below the yield strength of the. Webcorr provides corrosion consultancy services, corrosion expert witness and corrosion short courses for inhouse training, online and distance learning.

Hic usually occurs due to the effects of aqueous hydrogen charging of steel in wet h2s refinery process. 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. A corrosive medium especially chloridebearing or hydrogensulphide h 2 s media. The root cause of these failures was identified to be hydrogen induced stress cracking, hisc, where the hydrogen source was the cathodic protection system of the subsea facility. Hydrogeninduced cracking susceptibility in highstrength. Hydrogen assisted cracking of high strength alloys richard. The hydrogeninduced pitting corrosion mechanism in duplex stainless steel studied by currentsensing atomic force microscopy. Unstressed test specimens are exposed to a solution at temperature of. Jul 29, 2019 hydrogen induced cracking failures of sour gas processing equipment and transmission pipelines have been reported at facilities in libya, saudi arabia and other middleeastern plants. Hydrogeninduced craking hic, also referred to as hydrogen stress cracking or static fatigue, is a typical form of hydrogen embrittlement. This is a type of deterioration which can be linked to corrosion and corrosioncontrol processes.

Roles of microalloying elements in hydrogen induced. Hydrogen induced stress cracking of duplex stainless steel subsea. Hic steel hydrogen induced cracking supplier company. Hydrogeninduced stress cracking of swaged super duplex stainless steel subsea components, corrosion 757. This penetration can lead to the brittle fracture of materials that are normally ductile when hydrogen happens to be present in their environment.

Once again, the supply of steel with resistance to stress orientated hydrogen induced cracking sohic is very important and while there are testing procedures available, a specific sohic susceptibility test has not been standardised to date. Nonmetallic inclusions can affect resistance of steels to both general and localized corrosion, including pitting corrosion, stress corrosion cracking scc, and hydrogen induced cracking hic. Corrosionpedia what is sulfide stress cracking ssc. Susceptibility to hydrogen induced cracking of api 5l b and x52ms lowcarbon steels in nace 177a, 177b, and 284b solutions has been investigated by the present work. Hydrogen induced stress cracking hisc resistance and improvement methods for super duplex stainless steels. There are several types of tests to determine exact type of corrosion resistance property of any material. Hydrogen blistering occurs when hydrogen atoms diffuse into the steel, and hydrogen gas nucleates at internal defects and inclusions, forming voids which eventually generate enough pressure to locally rupture the metal. The hydrogeninduced cracking hic susceptibility of weld met als of hightensile strength ranging from 70 to 100 kgfmm2 100 to 143 ksi was investigated to estimate the lowest possi ble preheat and interpass temperatures to prevent cracking. Hydrogen induced cracking of subsea duplex stainless steel twi. Abstract precipitation hardened ph nibased alloys have proved to be sensitive to hydrogen induced stress cracking hisc, and hisc related failures in the oil and gas industry have been experienced in the case of uns n07718, uns n07725 and uns n0. Welding may cause increased hydrogen induced stress cracking susceptibility in the weld metal and in the haz adjacent to the fusion line. Hydrogen induced stress cracking of duplex stainless steel. The significance of these failures has led to research to define critical loading conditions for hisc, to allow confident design of components in future. Due to the fact that these pipes transport corrosive and highpressure fluids from harsh environments, they are damaged and eventually degraded.

This can occur during elevatedtemperature thermal treatments and in service during electroplating, contact with maintenance chemicals, wet h 2 s, corrosion reactions, cathodic protection, and operating in highpressure hydrogen containing environments. This was done by hydrogen precharging and stepwise loading in cortest proof rings, followed by an investigation of the fracture surfaces in a scanning. A comparative study of hydrogeninduced cracking resistances. Published by welding technology institute of australia wtia, silverwater, nsw, australia, 1999. A metallographic analysis of these steels was performed before and after nace tm0284 standard testing. Weld metal hydrogen cracking in pipeline girth welds, proc. Stress corrosion cracking scc results from the combined action of three factors.

Pdf resistance toward hydrogeninduced stress cracking of hot. Damage due to hydrogen embrittlement and stress corrosion. Corrosionpedia what is hydrogeninduced cracking hic. Assessment of the hydrogen induced stress cracking resistance of precipitation hardened nickelbased alloys using the slow strain rate tensile test. The failure of highstrength fasteners in aerospace equipment as a result of scc or hsc occurs infrequently and almost always unexpectedly. Sulfide stress cracking is the worst type of corrosion in the presence of hydrogen sulfide. Susceptible alloys, especially steels, react with hydrogen sulfide, forming metal sulfides and atomic hydrogen as corrosion byproducts. Sulfide stress cracking ssc is a form of hydrogen embrittlement which is a cathodic cracking mechanism.

Test is intended to evaluate resistance to hydrogeninduced stepwise cracking only, and not other adverse effects of sour environments such as sulfide stress cracking, pitting, or weight loss from corrosion. Hydrogen induced cracking susceptibility of highstrength. Plates of high strength, low alloy hsla steel jisg3115 spv50q were found to be susceptible to sulfide stress cracking and hydrogeninduced cracking hic in wet hsub 2s. Experience has shown that stainless steels can suffer from hydrogen induced stress cracking hisc under cathodic protection in seawater. Jun 03, 2018 hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms. Sulfide stress cracking an overview sciencedirect topics. It should not be confused with the term stress corrosion cracking which is an anodic cracking mechanism. Ferritic stainless steels, on the other hand, tend to be fairly resistant to hydrogen stress cracking due to their comparatively low hardness.

It involves the ingress of hydrogen into a component, an event that can seriously reduce the ductility and loadbearing capacity, cause cracking and catastrophic brittle failures at stresses below the yield stress of susceptible materials. Sulfide stress cracking is a function of hydrogen sulfide concentration as low as ppm, hydrogen sulfide partial pressure, stresses, material yield strength, temperature and ph. In the case of a crystal lattice becoming saturated or coming into contact with atomic hydrogen, many alloys and metals may. Unstressed test specimens are exposed to a solution at temperature of 25deg cent with continuous h2s gas flow. Hydrogen stress cracking can affect several different types of metals such as high strength structural, carbon, and low alloy steels, along with titanium, nickel, and aluminium alloys. Pdf hydrogeninduced stress cracking of swaged super duplex. The resistance toward hydrogen induced stress cracking hisc of forged and hot isostatically pressed hip super duplex stainless steel sdss according to uns s32760 have been compared by slow strain rate testing ssrt under various environmental conditions, comprising exposure to a 3. Journal of iron and steel research international 22. There are several types of stress corrosion cracking scc, for example, chloride induced scc and h 2 s induced scc. Hic testing is recommended to evaluate the resistance of pipeline and pressure vessel plate steels to hydrogen induced cracking corrosion caused by hydrogen absorption from aqueous sulfide corrosion.

Modelling hydrogen induced stress corrosion cracking in. Cracks can develop by both transgranular and intergranular paths. Hydrogen induced cracking results from atomic hydrogen being absorbed by solid metals. It is a complex process that is not completely understood because of the variety and complexity of mechanisms that can lead to embrittlement. Hydrogen assisted cracking of high strength alloys richard p. The results showed that the failure developed from a combination of factors, typical for hydrogeninduced stress cracking. Susceptibility to hydrogen blistering and hydrogen induced cracking can be apportioned to the quality of the steel plate used. Assessment of the hydrogen induced stress cracking resistance of. Another type of hydrogen corrosion, stressorientated hydrogen induced cracking sochic, is normally found in the base metal adjacent to the weld, where the stress point is highest due to the internal pressure of the. Sulfide stress corrosion cracking ssc, hydrogen induced cracking hic, linepipe, chromium, hydrogen sulfide. Hydrogen induced stress corrosion cracking in low and high. Sep 25, 2018 however, bp and shell experience some serious cracking of duplex steel in the mid 90ties and in beginning of the century. Efc publication 17, 2nd edition, corrosion resistant alloys for oil and gas production. Currently, thousands of kilometers of pipeline steels are transferring hydrocarbon fluids such as oil and natural gas in the world.

To date only duplex stainless steels, together with supermartensitic stainless steels, have been extensively tested. Previous, land based, hydro testing was satisfactory, so there was a clear delayed nature to the cracking behaviour, which is commonly associated with the involvement of hydrogen gas in. The path of crack growth in hydrogen embrittled steels is a function of the stress intensity factor, k mpavm. It is characterized by the brittle fracture of a normally ductile alloy under sustained load in the presence of hydrogen.

A small number of duplex and superduplex stainless steel components have failed in subsea service due to hydrogen induced stress cracking hisc. Although hydrogeninduced cracking and stress corrosion cracking are similar phenomena, both types of damage are usually described and treated separately. Hydrogen embrittlement and stress corrosion cracking. Stress corrosion cracking facts and how to reduce the risk.