API 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, is a standard that provides guidance on identifying, evaluating, and mitigating the various types of damage that can occur in fixed equipment used in the refining industry. The standard addresses various types of damage that can occur in metallic components, including damage mechanisms that can affect stainless steel.

Some of the damage mechanisms that can be applicable to stainless steel are:

  • Corrosion: Stainless steel is generally resistant to corrosion, but it can still be affected by corrosion under certain conditions. Corrosion can occur when the stainless steel is exposed to an environment that is highly acidic or basic, or when it comes into contact with certain types of chemicals.
  • Fatigue: Fatigue is the process of gradual failure that occurs in materials due to the accumulation of cyclic stress. Stainless steel can be susceptible to fatigue if it is subjected to repeated loading over a long period of time.
  • Hydrogen damage: Hydrogen can penetrate the surface of stainless steel and cause damage through a process known as hydrogen embrittlement. This can occur when the stainless steel is exposed to hydrogen gas or hydrogen-containing compounds.
  • Crevice corrosion: Crevice corrosion is a type of corrosion that occurs in small, confined areas, such as crevices, corners, and under gaskets. It can occur in stainless steel if the conditions in the crevice are not sufficiently oxygenated.
  • Stress corrosion cracking: Stress corrosion cracking (SCC) is a type of corrosion that occurs when a material is subjected to both tensile stress and a corrosive environment. Stainless steel can be susceptible to SCC if it is exposed to certain types of environments, such as high temperatures and high levels of chloride.
  • Thermal fatigue: Thermal fatigue is a type of fatigue that occurs due to the repeated expansion and contraction of a material as it is subjected to alternating high and low temperatures. Stainless steel can be susceptible to thermal fatigue if it is subjected to rapid temperature changes.
  • Erosion: Erosion is the process of wear and tear that occurs when a material is subjected to the action of a flowing fluid. Stainless steel can be susceptible to erosion if it is exposed to high velocity fluids, such as water or gases.
  • Erosion-corrosion: Erosion-corrosion is a type of damage that occurs when a material is subjected to both erosion and corrosion at the same time. Stainless steel can be susceptible to erosion-corrosion if it is exposed to high velocity fluids that contain corrosive substances.