Hydrogen-induced cracking and sulfide stress cracking test

As a form of hydrogen stress cracking, ssc is a cracking mechanism in pipelines, facilities piping and any equipment that comes in contact with sour wet h2s service conditions. Hydrogen sulfide h 2 s is a naturally occurring gas that can be deadly to humans and corrosive to oil and gas equipment, especially in the presence of water. Stressoriented hydrogen induced cracking sohic is a common, insidious form of wet h2s cracking. Sulfide stress cracking mostly occurs in very highly acidic environments. Transformable ferritic steels are susceptible to hydrogen induced scc in a wide range of aqueous media. It should not be confused with the term stress corrosion cracking which is an anodic cracking mechanism. Hydrogeninduced cracking an overview sciencedirect topics. It is a progressive type of failure that produces cracking at stress levels that are well below the materials tensile strength. Sulfide stress cracking ssc is just one of several forms of hydrogen. Element sulfide stress cracking ssc testing according the nace tm0177 iso. This phenomenon is generally termed sulfide stress cracking ssc when operating at room temperature and stress corrosion cracking scc when operating at higher temperatures. Sulfide stress corrosion cracking of steels corrosion.

Stress orientated hydrogen induced cracking sohic is a manifestation of sulfide. 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. Aug 02, 2014 the entrapped hydrogen makes cavities in metal that results in cracking due to weak ductility and tensile strength. When left untreated, both forms of corrosion can be very dangerous. Particular focus was placed on environmentally assisted cracking eac, namely hydrogeninduced cracking hic, stepwise cracking swc, stress corrosion cracking scc and sulfide stress cracking. The environmentinduced cracking eic of asannealed ni3si,ti and ni3si,ti with 2mo has been researched as functions of applied stress, chloride ion concentration, test temperature, and ph. Hydrogen induced sulfide stress cracking ssc under sour service conditions and in the simultaneous presence of external tensile stresses, metal materials can suffer sulfide stress cracking ssc. 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. Plates of high strength, low alloy hsla steel jisg3115 spv50q were found to be susceptible to sulfide stress cracking and hydrogen induced cracking hic in wet hsub 2s. Sulfide stress cracking nace mr01752002, mr0175iso 15156. Sulfide stress corrosion cracking and hydrogen induced cracking of a216wcc wellhead flow control valve body. According to hic and ssc laboratory tests and also with regard to cost of engineering materials, it was evident that the best alternative for the valve body alloy is. It is made up of a series of hic hydrogen induced cracking cracks that are stacked perpendicularly in.

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. Sulfide stress cracking tests should be performed in accordance with nace tm. Dec 19, 2019 sulfide stress cracking ssc is a type of hydrogen cracking which presents a cathodic embrittlement mechanism. Results provided insight on the role of steel quality and microstructure in susceptibility of cs to hic, stress oriented hydrogeninduced cracking sohic, and sulfide stress cracking ssc. Ssc is one of the many environmental cracking mechanisms resulting in pipeline steels exposed to aqueous sour service environments. Stressoriented hydrogeninduced cracking sohic test method. Ansinace tm0177, nace international, houston, tex, usa, 2016. All the test apparatus are manufactured to provide interchangeable connections and fittings. A comparative study of hydrogeninduced cracking resistances. May 22, 2018 hic, hydrogen induced cracking, hydrogen induced cracking test, ultrasonic, cscan, cscan. Hydrogen cracking is also named as toe cracking or underbead cracking due to its location of occurrence.

Hic test, hydrogen induced cracking test, step wise. The investigation of eic was carried out by applying a constant method in nacl solutions. Critical nominal stress and critical stress intensity factors for sulfide stress corrosion cracking of various steels were determined using fatigueprecracked, laboratory, cantilever beam specimens and short lengths of oil field casing and tubing pressured to failure. Roles of microalloying elements in hydrogen induced cracking. It is a complex process that is not completely understood because of the variety and complexity of mechanisms that can lead to embrittlement. During investigation many cracks were observed on the inner surface of the valve body grown from the surface pits. Hic test, hydrogen induced cracking test, step wise cracking. The effects of sulfide stress cracking on the mechanical properties. Hydrogeninduced cracking susceptibility in highstrength. The national association of corrosion engineers nace test method tm0177 is widely used to qualify metals for resistance to sulfide stress cracking and stress corrosion cracking in h 2 s environments.

Sulfide stress corrosion cracking and hydrogen induced cracking of. Lonestar technical services llc one stop solution for. As pipeline in wet h2s environment must consider its antihydrogeninduced cracking hic and sulfide stress corrosion cracking sscc performance, in this paper, to ensure l245apipe mechanical properties qualified under the premise, according to nace tm 02842003 and nace tm 01772005 standard conducted a test evaluation in wet h2s. A wide variety of corrosionrelated tests are undertaken to determine weight loss corrosion, intergranular attack, pitting corrosion, corrosion fatigue, stress corrosion cracking, sulfide stress cracking, and hydrogen induced cracking. Sulfide stress corrosion cracking sscc is a form of hydrogen embrittlement cracking which occurs when a susceptible material is exposed to a corrosive environment containing water and h2s at a critical level of applied or residual tensile stress. 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. Pdf sulfide stress corrosion cracking and hydrogen induced. A round robin laboratory assessment of hydrogen induced cracking and sulfide stress corrosion cracking of line pipe steelsresults variation and proposals for a modified test standard jan 1991 91. H 2 s is the gaseous and highly toxic molecular form often found in the subsurface.

Research on the steel for oil and gas pipelines in sour. Sulfide stress cracking ssc vs hydrogen induced cracking. Test for hydrogen induced cracking in essence, hic testing is actually an evaluation of the steel for susceptibility to hydrogen embrittlement. Test is intended to evaluate resistance to hydrogeninduced stepwise cracking only, and not other adverse effects of sour environments such as sulfide stress cracking. Sulfide stress cracking an overview sciencedirect topics. Badania odpornosci stali gatunku l360nb, l80, j55 na korozje naprezeniowa scc. Unstressed test specimens are exposed to a solution at temperature of. This raises questions about both the most appropriate steels, and test. Tm01772016, laboratory testing of metals for resistance to sulfide stress cracking and stress corrosion cracking in h2s environments testing of metals subjected to tensile stresses for resistance to cracking failure in lowph aqueous environments containing hydrogen sulfide h2s. Hydrogen formed on the surface of the steel by a cathodic corrosion reaction can diffuse into the material, causing embrittlement, and, if the region is subject to tensile stress, cracking can result. Untreated hic or sohic can lead to the steel losing its mechanical properties, such as its strength or ductility. Tcr offers a comprehensive range of material testing services for corrosion problems that include.

Basics of sulfide stress cracking ssc and stress corrosion cracking scc ssc and scc are cracking processes that develop in the presence of water, corrosion and surface tensile stress. As we know that both form of cracking are due to the absorption of atomic hydrogen that is produced by. It is characterized by the brittle fracture of a normally ductile alloy under sustained load in the presence of hydrogen. Sulfide stress cracking oil and gas pipelines wiley. Research on the steel for oil and gas pipelines in sour environment xiaodong shao 1, 2 1state key laboratory for performance and structure safety of petroleum tubular goods and equipment materials, no. Hydrogen induced damage can reveal fracture surfaces that cannot be easily distinguished from cleavage fractures. In order to use linepipe steels properly according to actual service environments, it is required to evaluate hic resistance of. Effects of h2s partial pressure and ph of test solution on. Tcr engineering mumbai corrosion testing, nace, astm. Introduction hydrogeninduced cracking sulfide stress cracking references. Sulfides can be generated from soluble iron sulfide minerals or from sulfatereducing bacteria.

Webcorr provides corrosion consultancy services, corrosion expert witness and corrosion short courses for inhouse training, online and distance learning. Largescale wet hydrogen sulfide cracking performance. Corrosionpedia what is sulfide stress cracking ssc. When metal is subjected to tensile stress with high level of hydrogen content, hydrogen induced cracking occurs. The hydrogen is first produced as hydrogen atoms h which normally combine rapidly to form hydrogen molecules h 2. According to hic and ssc laboratory tests the best. Hic detection technique appropriate for steel items a.

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 methane molecules create a pressure which leads to embrittlement and even cracking of the metal. Susceptible alloys, especially steels, react with hydrogen sulfide, forming metal sulfides and atomic hydrogen as corrosion byproducts. This test may be used for many purposes, and the applications of the results are beyond the scope of this standard. Metallographic examination identified the cracking as sulfide stress cracking ssc, stressoriented hydrogeninduced cracking sohic, and carbonate cracking. Processes or conditions involving wet hydrogen sulfide, i. The effects of alloying elements cuni, mo, and ti in line pipe steels on the susceptibility to sulfide stress cracking ssc was studied with respect to hydrogen permeation, crack nucleation, and crack propagation. Environmental cracking is a general term that includes. The results indicate that flow control valve body failed due to combination of. Hydrogen induced cracking of subsea duplex stainless steel.

Hydrogen induced cracking hiccauses and prevention. Hydrogen induced cracking hic when corrosion of steel occurs in an acid solution e. Sulfide stress cracking is a form of hydrogen embrittlement that occurs in highstrength steels and in localized hard zones in weldment of susceptible materials. Sulfide stress cracking ssc is a type of hydrogen cracking which presents a cathodic embrittlement mechanism. Hydrogen induced cracking steel features, applications and. 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. The test addresses the resistance of metals to cracking failure under the combined action of tensile stress and corrosion in aqueous environments conatining hydrogen sulfide h 2 s. The different methods have been used across industries to find out. Hydrogen sulfide stress corrosion cracking in materials for. Sulfide stress corrosion cracking ssc is a form of hydrogen embrittlement cracking which occurs when a susceptible material is exposed to a corrosive environment containing water and h2s at a critical level of applied or residual tensile stress. It involves atomic hydrogen, which is the smallest atom, that diffuses into a metallic structure. Sulfide stress cracking nace mr01752002, mr0175iso.

The tests are normally carried out according to nace tm0284. The blistering damage tends to form parallel to the surface and to the direction of hoop stress. Hic is susceptible to be presented in the sour gas system because of the. The control valve body failed due to combination of ssc and hic cracking in wet h2s environment. Hic test apparatus is suitable to use nace tm0284 specified solution a or solution b. Sulfide stress corrosion cracking test sscc as per nace tm0177. Hic detection, also known as hydrogeninduced cracking, is another nondestructive testing method that is used to examine components. Sulfide stress cracking ssc is a form of hydrogen embrittlement which is a cathodic cracking mechanism. This term should not be confused with stress corrosion cracking scs, since this is anodic in nature.

A comparative study of hydrogeninduced cracking resistances of. Below 20f 7c the diffusion rate of the hydrogen is so slow that the critical concentration is never reached. This standard presents metallic material requirements to provide resistance to sulfide stress cracking ssc andor stress corrosion cracking scc for petroleum production, drilling, gathering and flow line equipment, and field processing facilities to be used in hydrogen sulfide. Sep 07, 2009 sulfide stress cracking is most severe at ambient temperature, 20 to 120f 7 to 49c. The diffusion coefficient for the hydrogen atom in the spv50q steel was determined at 2560 c and the activation energy for diffusion was 24. Hic tests evaluate material susceptibility to hydrogen induced cracking in a. May 19, 2009 test for hydrogen induced cracking in essence, hic testing is actually an evaluation of the steel for susceptibility to hydrogen embrittlement. Susceptibility to sohic for linepipepressure vessel steels twi. The advanced ndt inspection techniques in singapore have been the most reliable for sometime because they protect the manufactured components and also protect the environment. Our laboratories can test both laboratory samples and full material samples according to nace tm0177 and nace tm0316 standards. Sohic is a type of cracking that can easily lead to failure and needs to be mitigated.

Sulfide, s2, and bisulfide, hs, are the corresponding ionic forms. 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 results indicate that flow control valve body failed due to combination of hydrogen induced corrosion cracking hicc and sulfide stress corrosion cracking sscc. Hydrogen induced cracking steel features, applications.

The test procedure involves the evaluation of resistance of pressure vessel steel plate and pipework steels to hydrogen reduced cracking caused by hydrogen absorption from aqueous sulfide corrosion. Sulfide stress cracking ssc testing southwest research. Evaluation of metallurgical, mechanical, and welding variables. This phenomenon has been known by many different names over the years, including stepwise cracking, hydrogen pressure cracking, blister cracking and hydrogeninduced stepwise cracking. Sulfide stress corrosion ssc and hydrogen induced cracking hic are chronic issues that appear on steel structures, particularly in petrochemical equipment. Pdf sulfide stress corrosion cracking and hydrogen.

Corrosion products were characterized by scanning electron microscopy and xray dispersive energy spectrometry, which were. Susceptibility to hydrogeninduced cracking of api 5l b and x52ms. 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. A metallographic analysis of these steels was performed before and after nace tm0284 standard testing. Nace and astm have standardized on the name hydrogeninduced cracking for this phenomenon in naceastm g193, defining it as. Nace international, standard test method laboratory testing of metals for resistance to sulfide stress cracking and stress corrosion cracking in h 2 s environments, tech. 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. The term active sulfide is used to denote compounds that revert to h 2 s gas when acidified with 2. Hydrogen induced cracking hic and stress oriented hydrogen induced cracking sohic are both forms of wet hydrogen sulfide h 2 s cracking. Sulfide stress corrosion cracking and hydrogen induced. For more information about how we perform hydrogen induced corrosion hic testing, or to request a quote. The wellhead flow control valve bodies which are the focal point of this failure case study were installed in some of the upstream facilities of khangirans sour gas wells. Also high strength structural steels which are welded are exposed to a certain hydrogen pickup which means a risk at fracture and blistering. Jun 03, 2018 hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms.

Woollin p and murphy w, hydrogen embrittlement stress cracking of superduplex stainless steel, proc conf corrosion 2001, nace international, paper 01018. Element carries out sohic testing to nace mr0175iso 15156 using test methods in bs 8701 full ring test, nace tm0177method a tensile or nace tm0316 four point bend. Sulfide stress cracking is the cracking of a metal under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulfide a form of hydrogen stress cracking. Intergranular cleavage fractures are often difficult to distinguish from cracks that have been formed by intergranular stress corrosion cracking.

Woollin p and gregori a, avoiding hydrogen embrittlement stress cracking of ferritic austenitic stainless steels under cathodic protection, proc conf omae 2004, paper 51203. Hydrogen embrittlement he also known as hydrogen assisted cracking hac and hydrogeninduced cracking hic, describes the embrittling of metal after being exposed to hydrogen. Sohic and carbonate cracking in these refining process environments have not been previously reported. The corrosion of steel pipelines by hydrogen sulfide has been a recurrent. They can develop without warning and lead to dangerous situations if left untreated. Element performs sulfide stress cracking ssc testing of metals subject to cracking under the combined action of tensile stress and corrosion in the presence of water and h2s, in compliance with nace tm0177 iso 15156 standards.

Hydrogen induced craking hic, also referred to as hydrogen stress cracking or static fatigue, is a typical form of hydrogen embrittlement. 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. Laboratory testing of steel l360nb, l80, j55 resistance to sulphide. Those who use the test should be aware that in some cases test results can be. The eic susceptibility of both intermetallic compounds increased with increasing test temperature and cl. According to hic and ssc laboratory tests and also with regard to cost of engineering materials, it was evident that the best alternative for the valve body alloy is a217 wc9 cast crmo steel. Sulfide stress corrosion cracking and hydrogen induced cracking of a216wcc wellhead flow control valve body article pdf available in case studies in engineering failure analysis.

However, the test environment of nace tm028496 standard hic test method is unnecessarily severe than that of actual sour service conditions. On site wet so2 astm g87 test inductively coupled plasma icp hydrogen induced cracking hic sulfide stress cracking ssc nace stress corrosion cracking scc nace leco oxygen nitrogen hydrogen onh stress rupture astm e9 creep astm e9 drop weight astm e208 impact astm e23 impact iso 148 nuclear power corporation india npcil approved hot tensile test. Hic in welding cold cracking haz cracking moisture n org compounds r primary sources of h. Sulfide stress cracking ssc vs hydrogen induced cracking hlc posted in refining, hydrocarbons, oil, and gas. Hydrogeninduced craking hic, also referred to as hydrogen stress cracking or static fatigue, is a typical form of hydrogen embrittlement.