Hydrogen sulfide gas causes severe corrosion of equipment, in particular piping. Hydrogen sulfide is particularly dangerous to equipment when moisture is present. However, at these low strengths, tubing collapse was encount ered and limited the strength of the joints. Sulfide stress cracking is a form of hydrogen embrittlement that occurs in highstrength steels and in localized hard zones in weldment of susceptible materials when the environment contains wet h 2 s. 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 corrosion cracking, also known as sulfide stress cracking ssc, is a stress corrosion cracking phenomena that occurs in the presence of hydrogen sulfide. Hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms. Steels react with hydrogen sulfide, forming metal sulfides and atomic hydrogen as corrosion byproducts. Corrosionpedia what is sulfide stress cracking ssc. Sulfide stress cracking an overview sciencedirect topics.
Sulfide stress cracking is a function of hydrogen sulfide concentration as low as ppm, hydrogen sulfide partial pressure, stresses, material yield strength. Hydrogen sulphide stress corrosion cracking in materials for. Hydrogen sulfide is a chemical compound with the formula h 2 s, and is often a colorless gas with a rotten egg odor, commonly referred to as sewer gas. Pdf sulfide stress corrosion cracking and hydrogen induced. These valve bodies have been operating satisfactorily for 3 years in wet h2s environment before some pits and cracks were detected in all of them during the. It is applied if the hydrogen sulfide content of the gas phase exceeds a partial. Sulfide stress corrosion cracking of steels corrosion. In the case of a crystal lattice becoming saturated or coming into contact with atomic hydrogen, many alloys and metals may. Wet hydrogen sulfide h2s cracking inspectioneering. In the usa, nace international issues a periodically updated standard mr0175 nace 2000 for materials selection for such service. Sulfide stress cracking ssc occurs at locations where atomic hydrogen is able to diffuse at sites of high internal stress, such as grain boundaries, inclusions and. Sulfide stress cracking is the worst type of corrosion in the presence of hydrogen sulfide.
Sulfide stress cracking is a form of hydrogen embrittlement that occurs in high strength steels and in localized hard zones in weldment of susceptible materials. The effects of sulfide stress cracking on the mechanical properties. Corrosionpedia explains sulfide stress cracking ssc ssc begins when steels and other susceptible alloys form a reaction with hydrogen sulfide, resulting in atomic hydrogen and metal sulfides as by products of corrosion. Susceptible alloys, especially steels, react with hydrogen sulfide, forming metal sulfides and atomic hydrogen as corrosion byproducts. Sulfide stress cracking of highstrength steels is a problem in handling sour hydrogen sulfide containing crude oil or natural gas. Hydrogen sulfide stress corrosion cracking of high. Corrosionpedia what is hydrogeninduced cracking hic. If the presence of hydrogen sulfide causes entry of hydrogen into the component, the cracking phenomenon is often termed sulphide stress cracking ssc. Other mechanisms of introduction of hydrogen into metal are galvanic corrosion, as well as chemical reactions with acids or other chemicals. One of these chemical reactions involves hydrogen sulfide in sulfide stress cracking ssc, a significant problem for the oil and gas industries. Failure occurs with an unusual tendency for cracks to form at 45 degrees to the direction of tensile stress.
Hydrogen sulfide cracking of carbon and alloy steels. Hydrogen sulfide h 2 s is a colorless, flammable, and extremely hazardous gas with a strong rotten egg odor. In turn, atomic hydrogen can combine to build h2 onto the metal surface or disperse into the matrix of the metal. 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. Sulphide stress cracking is prevented by minimising the hardness and strength of the alloys used for wet h2s systems. Sulfide stress cracking ssc is a form of hydrogen embrittlement which is a cathodic cracking mechanism.
Corrosion of metal and concrete is a major issue associated with the generation and oxidation of hydrogen sulfide. 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. It involves atomic hydrogen, which is the smallest atom, that diffuses into a metallic structure. It should not be confused with the term stress corrosion cracking which is an anodic cracking mechanism. Sulfide stress cracking is also called hydrogen sulfide cracking, sulfide cracking, sulfide corrosion cracking and sulfide stresscorrosion cracking. Sulfide stress cracking mostly occurs in very highly acidic environments. Effects of steel composition and production technology on hydrogen. The atomic hydrogen can diffuse into the metal matrix. Abstract high strength 244,000 psi ultimate tensile strength cold drawn carbon steel wire is susceptible to cracking in hydrogen sulfide solutions at room temperature at stress levels less than 15% of the ultimate strength. In this situation, cracking failures can often be thought of as a type of stress corrosion cracking. Hydrogen sulfide is known to cause or assist in the mechanism of cracking with many alloy types including low carbon steels, low alloy steels, alloy steels, tool steels, martensitic stainless steels, ferritic stainless steels, austenitic stainless steels, duplex stainless steels, nickelcopper alloys, and nickelbase alloys. H 2 s damage can lead to rapid and extensive damage to metals, including uniform corrosion, pitting, and stepwise cracking.