prbset094324 - spontaneously passivates. Explain the...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
EMA 4324 - Problem Set 9 9-1 [Jones 4-9] Given active-passive alloys A and B having the following electro-chemical parameters: [a] Which will be the more corrosion resistant under reducing conditions [active state]? Why? [b] Which will be the more corrosion resistant in the passive state? Why? [c] Which is more easily passivated by dissolved oxidizers? Why? [d] Which is more corrosion resistant in strongly oxidizing solutions? Why? [e] Which would be more easily protected by anodic protection? Why? 9-2 [Jones 4-11]. You have a titanium tank in you plant which is used to store 10% muriatic acid [commercial low cost hydrochloric acid], which contains as supplied 0.5% ferric chloride as an impurity. Careful measurements have shown that the tank is resistant to this media because it
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: spontaneously passivates. Explain the following using appropriate polarization diagrams if necessary. [a] Your supplier offers you some muriatic acid containing 2% ferric chloride at a big discount because other consumers reject it on the basis of its deep orange color. If ferric salts are tolerable in your process, will this acid corrode your tank more rapidly than the regular muriatic acid? [b] An excess of pure hydrochloric acid with no detectable ferric salts becomes available from another part of the plant. Can you take this acid into your storage tank without any risk of increasing corrosion rate? 1.2 1x10-6 0.3 0.1 7x10-7-0.200 B 0.7 1x10-5 0.1 1x10-6-0.400 A E tr , V I pass , A E pp , V b A , V I corr , A E corr , V alloy...
View Full Document

Ask a homework question - tutors are online