Nace Sp0170 Pdf !link! -

To mitigate this catastrophic failure mode, NACE International (now AMPP) developed the standard practice . Understanding this standard is essential for materials engineers, inspection personnel, and plant operators tasked with maintaining asset integrity during downtime. What is NACE SP0170?

Alkaline solutions often include a wetting agent or surfactant to help penetrate thick hydrocarbon films or heavy sulfide scales.

PTA SCC is a form of rapid intergranular cracking that occurs when sensitized austenitic stainless steels (those exposed to high service temperatures) are subjected to polythionic acids . These acids form when sulfide corrosion products (metal sulfides) react with oxygen and moisture nace sp0170 pdf

The 2018 version of the standard (NACE SP0170-2018) is the most recent and supersedes all previous versions, including the 2012 edition . The current version has a page count of 16 pages .

The technical standard , officially titled "Protection of Austenitic Stainless Steels and Other Austenitic Alloys from Polythionic Acid Stress Corrosion Cracking During a Shutdown of Refinery Equipment," is a foundational document for asset integrity in the petroleum refining industry. Maintained by the Association for Materials Protection and Performance (AMPP) , this standard maps out exact operational workflows to shield critical components from devastating, rapid structural failures during planned downtimes. Alkaline solutions often include a wetting agent or

The NACE SP0170 standard outlines the procedures and best practices for designing, installing, and maintaining cathodic protection systems for reinforced concrete structures. Cathodic protection is a technique used to control the corrosion of metal surfaces by making them the cathode of an electrochemical cell. In the context of reinforced concrete, CP systems drive the corrosion reaction away from the steel reinforcement, thereby protecting it from corrosion.

Identify all equipment containing austenitic stainless steels operating in the sensitization temperature range with sulfur present. The current version has a page count of 16 pages

This standard is directed toward preventing PTA SCC by detailing methods to neutralize these acids or prevent their formation. Key Mitigation Methods in NACE SP0170-2018

is a form of intergranular stress corrosion cracking that affects sensitized austenitic alloys (like 300-series stainless steels). It occurs when three conditions are met simultaneously:

This complex acid can then attack "sensitized" austenitic stainless steel—material that has been rendered susceptible to intergranular corrosion due to thermal effects from welding or high-temperature service—while the metal is under tensile stress, leading to SCC. The cracks typically appear as a network of fine, branching lines along the grain boundaries.