The ssc of medium strength steels has been a continuing source of trouble in the oil fields, and from these troubles has evolved in international standards 6. Hic usually occurs due to the effects of aqueous hydrogen charging of steel in wet h2s refinery process. The effects of cu and ni addition on the properties of the hic were also investigated. Another type of hydrogen corrosion, stressorientated hydrogen induced cracking sochic, is normally found in the base metal adjacent to the. Wet hydrogen sulphide h2s cracking in steel has been a problem in petroleum refining and upstream oil and gas processing since.
When the crystal lattice is in contact or is saturated with atomic hydrogen, the mechanical. Abstract hydrogen induced cracking hic has been studied phenomenologically. In the case of a crystal lattice becoming saturated or coming into contact with atomic hydrogen, many alloys and metals may. It occurs at a rate that depends on the packaging of the iron unit cell, that is, greater diffusibility in the ferrite phase bcc than in the more compact austenite phase fcc. Hydrogen induced cracking hic is a form of tiny blistering damage caused by a high concentration of hydrogen in steel. Ultrasonic detection of hydrogen induced cracking hic in. Hydrogen induced cracking steel features, applications and. A small number of duplex and superduplex stainless steel components have failed in subsea service due to hydrogen induced stress cracking hisc. Particularly common to the oil and gas industry where the use of steel.
Hydrogeninduced craking hic, also referred to as hydrogen stress cracking or static fatigue, is a typical form of hydrogen embrittlement. Hydrogen induced cracking the crack thickness rate a516gr70 ctr hic plate. Hydrogen induced cracking steel features, applications. Abstract a mathematical model was proposed for determining the crack growth rate of hydrogeninduced cracking hic in steel plates exposed to a sour gas. Hydrogen blistering a special case of hydrogen damage is known as hydrogen blistering. Nov 28, 2018 hydrogen induced cracking, or hydrogen embrittlement, is a chemical phenomenon that causes metal alloys to fracture due to a buildup of hydrogen molecules within the crystal lattice structure. Hydrogen induced cracking is a mechanical fracture caused by penetration and diffusion of atomic hydrogen into the internal structure of steel, which changes into molecular. Hydrogen induced crack resistant hic steel plate brown mcfarlane offers the widest range of carbon and stainless steel plate, available exstock.
Welding of carbon and low alloy steels and hydrogen. Hydrogen induced cracking of subsea duplex stainless steel. Hic is especially prevalent in iron alloys because of the restricted slip capabilities in the predominantly bodycentered cubic bcc structure. Evaluation of haz hydrogeninduced cracking for high. Cosasco provides hydrogen monitoring solutions for corrosion control such as hydrogen blistering hydrogen induced cracking hic on steel. Corrosion loops were established for the sour environment and revealed that hic is one of the potential damage mechanisms that could affect the sour gas system.
Figure 1 blistering resulting from hydrogen attack hydrogen induced cracking hic is characterized by an inplane stepwise cracking with and may results in a throughthickness crack linkage 2 figure 2. Hic steel hydrogen induced cracking supplier company. As a first step, a literature survey was undertaken on hydrogen induced cracking hic phenomena. Hydrogen embrittlement also known as hydrogen assisted cracking and hydrogeninduced cracking, describes the embrittling of metal after being exposed to hydrogen. Paper presented at 29th international conference on offshore mechanics and arctic engineering omae 2010, shanghai, china, 611 june 2010. The blistering damage tends to form parallel to the. Hic test, hydrogen induced cracking test, step wise cracking. With the increasingly serious problem of hydrogen sulfide corrosion, the development of antisulfur seamless pipeline is imminent, and the performance of sulfurresistant is the key. Jun 03, 2018 hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms. This is a problem commonly found in wet h2ssour service operating environments such as in the oil, gas and petrochemical industry. It is a complex process that is not completely understood because of the variety and complexity of mechanisms that can lead to embrittlement. Hydrogen induced cracking hic and the blistering of carbon steel are both such unexpected corrosion phenomenon.
Hydrogeninduced cracking and healing behaviour of x70. The hydrogen is first produced as hydrogen atoms h which normally combine rapidly to form hydrogen molecules h 2. Hic, hydrogen induced cracking, hydrogen induced cracking test, ultrasonic, cscan, cscan. It is characterized by the brittle fracture of a normally ductile alloy under sustained load in the presence of hydrogen. A comparative study of hydrogeninduced cracking resistances. Webcorr provides corrosion consultancy services, corrosion expert witness and corrosion short courses for inhouse training, online and distance learning. Hydrogen induced cracking hic is a phenomenon mainly associated with welds in low alloy steels. Evaluation of haz hydrogeninduced cracking for high strength.
Masterhic is masteel uk limiteds designation for hic steel for fine grain pressure vessel steels offering specific and superior properties for sour gas application. Also high strength structural steels which are welded are exposed to a certain hydrogen pickup which means a risk at fracture and blistering due to hic. Abstract a mathematical model was proposed for determining the crack growth rate of hydrogen induced cracking hic in steel plates exposed to a sour gas. Hydrogen induced cracking hic occurs when carbon steel is exposed to hydrogen sulphide h2s and is the direct result of electrochemical corrosion r. Hydrogen induced cracking hic is most commonly encountered in steels but other metals are susceptible, as shown in table 33. A comparative study of hydrogeninduced cracking resistances of. Carbon seamless steel pipe is mainly used for conveying highpressure oil and gas near the wellhead. Hic is susceptible to be presented in the sour gas system because of the. Evaluation of haz hydrogeninduced cracking for high strength steels aws podcast. Naceastm g193 1 includes the following description of hydrogen blistering. Hydrogeninduced cracking hic in steel is a risk problem when steels are charged with hydrogen in service as in various hydrogen sulfide environments like. Effect of microstructure on hydrogeninduced cracking of. Aug 15, 2016 evaluation of haz hydrogen induced cracking for high strength steels aws podcast.
Also high strength structural steels which are welded are exposed to a certain hydrogen pickup which means a risk at fracture and blistering. This is a unique mode of mechanical failure that most commonly affects low alloys and highhardness steel grades such as titanium ti. Corrosionpedia what is hydrogeninduced cracking hic. Additionally, hydrogen atoms diffuse through metals and coalesce. According to nace tm0284, the ctr result should be less 1. Hic test specimens are machined with thickness of 530mm, width 20mm, and length of 100mm is suitable for testing as per the nace standard. 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. The significance of these failures has led to research to.
Hic steel plates hic resistant steel plates hic tested. 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. Production of hic resistant steels total materia article. Hydrogeninduced cracking, or hydrogen embrittlement, is a chemical phenomenon that causes metal alloys to fracture due to a buildup of hydrogen molecules within the crystal lattice structure. Wet hydrogen sulphide h2s cracking in steel has been a problem in petroleum refining and upstream oil and gas processing since the 1950s. Hydrogen induced cracking of carbon seamless pipe materials. This is a type of deterioration which can be linked to corrosion and corrosioncontrol processes.
Hydrogen induced cracking hic represents a common challenge, especially in the petroleum and refinery industry where the purity and overall quality of the steel is of paramount importance. Atomic hydrogen, and not the molecule, is the smallest atom and it is small enough to diffuse readily through a metallic structure. Hydrogen pressure, assisted by hydrogen embrittlement then can cause cracks to appear without the. Hydrogen induced cracking hic tests demonstrate the high quality of our steel. A detailed failure investigation showed that the vessel had experienced severe hydrogen induced cracking hic, the cause of this cracking has been traced to high hydrogen fluxes brought on by a combination of operating conditions, poor metallurgy for the service and a tendency for the alkanolamine to charge hydrogen at very high acid gas. The presence of hydrogen atoms in a metal degrades some of its mechanical properties, especially its ductility, leading in some cases to embrittlement. Although this can occur in very high purity laboratory steels in presumably clean grain boundaries, in commercial steels it normally occurs in conjunction with segregated elements that reduce intergranular cohesion. Jul 29, 2019 hydrogen induced cracking hydrogen induced cracking hic when corrosion of steel occurs in an acid solution e.
In this issue, the characteristic features and principal causes of hydrogen cracks are described. Weld metal cracking hydrogen cracking induced cracking crack susceptibility saw cracking tests basic bonded flux diffusible hydrogen flux bake temperature critical temperature 100140 ksi steel in this investigation, the hic susceptibil ity of multipass hightensile strength weld metals ranging from 70 to 100 kgfmm2. Specificationsgrades asmeastm saa 516 grades 606570. Mechanisms of hydrogen induced cracking in pipeline steels. Abstract hydrogeninduced cracking hic has been studied phenomenologically.
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. Most hydrogen induced cracking hic in high strength quenchedandtempered ferritic steels occurs along prior austenite grain boundaries. It occurs at a rate that depends on the packaging of the iron unit cell, that is, greater diffusibility in the ferrite phase bcc than in. Hic resistant steel plate is used by boiler makers and fabricators when hydrogen induced cracking is a big risk. An hic steel plate is a carbon steel plate which is tested specifically to assess the susceptibility of the material to hydrogen induced cracking, a problem which is commonly found in the oil, gas and chemical industries in what are known as wet h2s and sour service environments. Hydrogen embrittlement he also known as hydrogen assisted cracking hac and hydrogeninduced cracking hic, describes the embrittling of metal after being exposed to hydrogen. Sa 516 hydrogen induced cracking american alloy 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. Hydrogen induced cracking hic causes and prevention.
Hydrogen induced cracking hic occurs when carbon steel is exposed to hydrogen sulphide h 2s and is the direct result of electrochemical corrosion reactions between the sour service or wet h 2s environment. Hydrogen induced cracking hydrogen induced cracking hic when corrosion of steel occurs in an acid solution e. The influence of cu and ni on the hic properties of the seamless pipe materials and the s content in the steel were also investigated. The catastrophic cracking of steels in hydrogen sulfide h 2 s environments referred to as sulfide stress cracking is a special case of hydrogen stress cracking. Through the testing of hydrogen induced cracking hic, it could be verified that the presence of h 2 s along with the exposure to hydrogen causes different effects in x80, x65 steel tubes and in. The steps of a possible mechanism of hydrogeninduced cracking hic can be, first, interstitial diffusion of hydrogen atoms under the steel surface. The formation of subsurface planar cavities, called hydrogen blisters, in a metal resulting from excessive internal hydrogen pressure. The crack thickness rate ctr to one of evaluate hic result way. This assessment discusses hic in light of hydrogen transport through pipeline steel microstructures and crack initiation and propagation.
The build up of hydrogen sulfide in pressure vessel tanks found in these industries is a major concern as it leads. Hydrogen induced cracking test apparatus is rectangular provided with ready to use connections fittings. It is also called hydrogen assisted cracking hac and delayed cracking since it does not occur right after welding, but a few hours or days after the weld has completely cooled down to ambient temperature. The blistering damage tends to form parallel to the surface and to the direction of hoop stress. Hydrogeninduced cracking hic is the stepwise internal cracks that connect adjacent hydrogen blisters on different planes in the metal, or to the metal surface. Hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms. This type of damage typically occurs in carbon steels that are exposed to hydrogen sulphide, cyanides, hydrofluoric acid and. The most common forms of wet h 2 s cracking are hydrogen induced cracking hic, stressoriented hydrogen induced cracking sohic, and sulfide stress cracking ssc. Hydrogen induced cracking hic in the oil and gas industry. Hic test, hydrogen induced cracking test, step wise. Hic usually occurs due to the effects of aqueous hydrogen charging of steel in wet h2s refinery process environments. The production process for hic resistant steels includes critical desulphurization techniques including the injection of magnesium and stirring by bottom.
Hydrogen embrittlement he also known as hydrogen assisted cracking hac and hydrogeninduced cracking hic, describes the embrittling of metal after. Hic resistant steel is manufactured via the electric. Hydrogeninduced cracking susceptibility in highstrength. Hydrogen induced cracking of subsea duplex stainless steel twi. Hydrogen induced craking hic, also referred to as hydrogen stress cracking or static fatigue, is a typical form of hydrogen embrittlement. Hydrogeninduced crack growth rate in steel plates exposed. The steps of a possible mechanism of hydrogen induced cracking hic can be, first, interstitial diffusion of hydrogen atoms under the steel surface. Hydrogeninduced cracking hic is a far too common type of failure.
Hic test apparatus is supplied with essential spares for uninterrupted long term testing. May 19, 2009 hic steel is plate which is tested to reduce the effects of hydrogen induced cracking in a wet h2s or sour service environment. This assessment discusses hic in light of hydrogen transport through pipeline. The factors which contribute to hic are i presence of h2, ii high tensile stress, iii susceptible microstructures, iv temperatures which are between around 200 deg c and 100 deg c, and v time. The role of hydrogen in the welding of steel duration. Mechanisms that have been proposed to explain embrittlement include the formation of brittle hydrides, the creation of voids that can lead to bubbles and pressure buildup within a material and e. The tests are normally carried out according to nace tm0284. 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. The principal distinguishing feature of this type of crack is that it occurs in ferritic steels, most often immediately on welding or a short time after welding.
Sa 516 restricted to low sulpher and residual elements. It involves atomic hydrogen, which is the smallest atom, that diffuses into a metallic structure. 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. Welding of carbon and low alloy steels and hydrogen induced. The microstructure at the hic fracture of a mild carbon steel. The effect of microstructure on hic is discussed for steels having two different levels of nonmetallic inclusions. Carbon and low alloy steels which are subjected to sour service environments may be susceptible to hydrogen induced cracking hic. Hydrogeninduced crack growth rate in steel plates exposed to.
May 22, 2018 hic, hydrogen induced cracking, hydrogen induced cracking test, ultrasonic, cscan, cscan. Hydrogen cracking may also be called cold cracking or delayed cracking. Hydrogen induced cracking hic occurs when carbon steel is exposed to hydrogen sulphide h2s and is the direct result of electrochemical corrosion reactions between the sour service or wet h2s environment. Defects hydrogen cracks in steels identification twi. The most common grades of hic resistant steel plate is a516 to asmeastm standards. In the presence of water and hydrogen sulfide, atomic hydrogen is produced and enters the steel, recombining at discontinuities to form molecular gases hydrogen gases. Combatting the problem of hydrogen induced cracking in sour service, hic steel plate is carbon steel plates which are tested to assess the susceptibility of the material to hydrogen induced cracking.
Hydrogen induced cracking hic is a failure mechanism resulting in sudden exposures and cracks due to growing laminations inside the base material and welds. Sa 516 hydrogen induced cracking hic american alloy steel. Hydrogen induced cracking hic occurs when carbon steel is exposed to hydrogen sulphide h 2 s and is the direct result of electrochemical corrosion reactions between the sour service or wet h 2 s environment. Processes or conditions involving wet hydrogen sulfide, i. Cracking occurs due to a significant loss in ductility. Hydrogen induced cracking hic on steel for corrosion. Hydrogen induced cracking is a form of planar cracking when atomic hydrogen diffuses into the carbon or low alloy steel plate.
Hic is generally limited to steels having a hardness of 22 or greater on the rockwell c scale. Hicresistant steel grades are novel metal alloys that have been engineered to resist hydrogeninduced cracking and provide longlasting. Material and metallurgical parameters were investigated. Wet h2s service what are the requirements for steel plate. Hic hydrogen induced cracking is the result of a corrosive reaction between carbon steel and hydrogen sulphide. Factors influencing hydrogen induced cracking welding. Hydrogen induced cracking hic remains a prominent issue for oil and gas exploration in challenging environments. The role of grain boundaries in hydrogen induced cracking. Nako2 hydrogen induced cracking hic remains a prominent issue for oil and gas exploration in challenging environments. Hydrogeninduced cracking an overview sciencedirect topics. Hydrogen induced cracking hic there are several categories of hydrogen phenomena that are localized in nature. In these conditions, hydrogen induced cracking hic due to ingress of hydrogen into steel from h2s gas is a significant. Wet hydrogen sulfide h2s cracking inspectioneering. Hydrogen damage figure 1 is encountered in many steel processes, such as pickling, electroplating and welding.
328 1479 793 719 1074 762 675 1584 1099 1556 251 232 440 1029 828 66 1509 1267 251 1314 185 577 550 1397 700 998 686 1062 684 1161 340 48 819 137 321 9 1212 858 1136