NACE MR0175 is a standard published by the National Association of Corrosion Engineers (NACE) that provides guidelines for the selection and use of materials in environments where sour service conditions are present. Sour service refers to conditions where hydrogen sulfide (H2S) is present in oil, gas, or other process fluids, which can lead to sulfide stress cracking (SSC) and other forms of corrosion in metallic materials.
NACE MR0175 was originally published in 1975 and has since undergone several revisions, with the latest version being released in 2015 and renamed as ISO 15156. The standard specifies the requirements for metallic materials that are resistant to SSC and other forms of corrosion in sour service environments, including carbon steels, low-alloy steels, stainless steels, nickel alloys, and other alloys.
NACE MR0175 provides guidelines for the materials selection process, including the chemical composition, mechanical properties, and heat treatment requirements for materials used in sour service environments. The standard also includes guidelines for the design, fabrication, and installation of equipment and structures in sour service environments to minimize the risk of corrosion and other forms of damage.
Overall, NACE MR0175 is an important standard for the oil and gas industry and other industries where sour service conditions are present. Compliance with the standard helps to ensure the safe and reliable operation of equipment and structures in these environments, while minimizing the risk of corrosion and other forms of damage.