A. 0.25 wt.%
B. 0.15 wt.%
C. 0.18 wt.%
D. 0.35 wt.%
A. failure caused by repeated cycling from elevated temperature, typically characterized by through-wall oxide filled ruptures with little bulging.
B. elevated temperature failure caused by diffusion of hydrogen into the material, typically characterized by blistering and cracking.
C. elevated temperature failure caused by localized overheating, typically characterized by bulging and thinning.
D. cracking failure caused by sulfides formed at elevated temperature that convert to acids on exposure to moisture and oxygen.
A. Areas where there is significant hydrogen blistering.
B. Areas with temperatures above 300°F (149°C).
C. Hardened steels.
D. Steel weldments.
A. Caustic storage tanks (non-postweld heat treated)
B. Caustic injections in crude units
C. Caustic treaters
D. Boilers and steam generating equipment
A. Water phase
B. Vapor phase
C. Two phase
D. Hydrocarbon phase
A. Molybdenum content of the steel to 6%
B. Carbon equivalent of the alloy
C. Chromium content of the steel
D. Nickel content of the steel
A. Upgrade the metallurgy of the exchanger
B. Lower the water velocity
C. Increase the tube diameter
D. Increase the process side temperature above 212°F (100°C)
A. Naphthenic acid corrosion
B. Sulfuric acid corrosion
C. Polythionic acid cracking
D. Sour water acid corrosion
A. Ammonium bisulfide
B. Ammonium chloride
C. Caustic
D. Amine
A. rough pits and pock marks.
B. linear striations.
C. grooves and gullies.
D. smooth pits.
