API 571 Flashcards
Amine Stress Corrosion Cracking - most often found at? and appearance
- found at or adjacent to non-postweld-heat-treated carbon steel welds or in
highly cold worked parts. - localized corrosion
Amine Stress Corrosion Cracking-Affected Material?
Carbon steel and low-alloy steels.
ATMOspheric Corrosion-description?
Corrosion that occurs from moisture associated with atmospheric conditions. Marine environments and moist, polluted industrial environments with airborne contaminants are the most severe.
Atmospheric Corrosion-Affected Material?
Carbon steel, low-alloy steels, and copper alloyed aluminum
Boiler Water and Stream Condensate Corrosion-due to?
result of dissolved oxygen and/or carbon dioxide, Flow accelerated corrosion (FAC) in these systems may occur either as general wall thinning corrosion or localized corrosion at high velocity, high turbulence, or change of flow direction locations
Boiler Water and Stream Condensate Corrosion-Affected Material?
Carbon steel and low-alloy steels.
Caustic Corrosion-Affected Material?
Primarily carbon steel, low-alloy steels, and 400 series SS.
Caustic Corrosion-likely to occur at what temp?
In high-solution-strength caustic, temperatures above about 170 °F (75 °C)
Caustic Corrosion-damage appearance?
Caustic gouging is typically characterized by localized metal loss,
Caustic Stress Corrosion Cracking
equipment exposed to caustic at elevated temperature, primarily adjacent to non-PWHT’d welds.
Caustic Stress Corrosion Cracking-Affected Material?
Carbon steel, low-alloy steels, and 300 series SS are susceptible.
Caustic Stress Corrosion Cracking-Prevention/Mitigation
A heat treatment at 1150 °F (620 °C) minimum with a minimum holding time of 1 hr is considered an effective stress relieving heat treatment for carbon steel.
Corrosion Under Insulation-critical factors (temps)
- carbon steel, low-alloy steel, and 400 series SS equipment operating between 10 °F (−12 °C) and 350 °F (175 °C).
- For 300 series SS, where Cl− SCC is the concern, refiners generally focus on the temperature range of
140 °F (60 °C) to 350 °F (175 °C). - or duplex stainless steel, where Cl− SCC is the concern, refiners generally focus on the temperature
range of 280 °F (140 °C) to 350 °F (175 °C).
Corrosion Under Insulation-Affected Material?
Carbon steel, low-alloy steels, 300 series SS, 400 series SS, and duplex stainless steels.
Sulfidation-damage description?-Affected Material?
carbon steel, low-alloy steels, 400 series SS, and 300 series SS. Nickel-based alloys
NOT ALUMINUM
Sulfidation-Inspection and Monitoring?
UT thickness measurement or RT
Thermal Fatigue-appearance of damage
dagger shaped, transgranular, and oxide filled, transverse
Erosion/Erosion – Corrosion-Affected Material?
All metals, but mostly carbon steel and copper alloys in refining. Refractories are also affected.
aluminum susceptible too
Erosion/Erosion – appearance of damage
localized loss in thickness in the form of
grooves, gullies, waves, rounded holes, valleys,
Hydrochloric Acid Corrosion-affected materials
all common materials