API 571 Damage Mechanisms (as per
API 570)
Highest corrosion rate for atmospheric corrosion? - answer Marine and industrial, 20
mpy
Up to what temp does atmospheric corrosion increase? - answer250F
How to inspect for atmospheric corrosion? (Three) – answer VT, UT thickness, profile
RT
What materials does atmospheric corrosion affect? (Three) - answer Low alloy, carbon
steel, Cu alloyed Al
What materials does boiler water and steam condensate affect? (Two) - answer Low
alloy, carbon steel
What does BWSC corrosion stem from? - answerCO2 and O2 (pitting) corrosion
What can increase resistance to BWSC corrosion? (Three elements) – answer Cr, Cu,
Mo
In BWSC corrosion, flow assisted corrosion is affected by which temp and pH -
answer300F, low pH
What NDE used in BWSC? (Two) - answerUT and RT to monitor wall thickness
What materials does caustic corrosion affect? - answer300 SS, 400 SS
How does caustic corrosion come about? - answerCaustic added to BFW to neutralize
acids, or remove S or Cl-
What does caustic corrosion look like? (general + temp, local) - answerGeneral thinning
at high temps (above 175F) and localized corrosion as gouging
How to prevent caustic corrosion? - answerMaterial selection
What materials are affected by CUI? - answerLow alloy steel, carbon steel, all SS
What materials are affected by erosion and erosion/corrosion? - answerAll
API 570)
Highest corrosion rate for atmospheric corrosion? - answer Marine and industrial, 20
mpy
Up to what temp does atmospheric corrosion increase? - answer250F
How to inspect for atmospheric corrosion? (Three) – answer VT, UT thickness, profile
RT
What materials does atmospheric corrosion affect? (Three) - answer Low alloy, carbon
steel, Cu alloyed Al
What materials does boiler water and steam condensate affect? (Two) - answer Low
alloy, carbon steel
What does BWSC corrosion stem from? - answerCO2 and O2 (pitting) corrosion
What can increase resistance to BWSC corrosion? (Three elements) – answer Cr, Cu,
Mo
In BWSC corrosion, flow assisted corrosion is affected by which temp and pH -
answer300F, low pH
What NDE used in BWSC? (Two) - answerUT and RT to monitor wall thickness
What materials does caustic corrosion affect? - answer300 SS, 400 SS
How does caustic corrosion come about? - answerCaustic added to BFW to neutralize
acids, or remove S or Cl-
What does caustic corrosion look like? (general + temp, local) - answerGeneral thinning
at high temps (above 175F) and localized corrosion as gouging
How to prevent caustic corrosion? - answerMaterial selection
What materials are affected by CUI? - answerLow alloy steel, carbon steel, all SS
What materials are affected by erosion and erosion/corrosion? - answerAll
