Question

Describe a simple test you will perform to ascertain the corrosion rate of materials? Derive an expression for the corrosion rate of materials. What is the process of aluminium anodising? Plain carbon steel immersed in sea water has a uniform corrosion rate expressed as 0.127 mm per year. The density of iron is 7.87Mg/m2. The atomic weight of Fe is 55.8 g/mol a. Calculate the weight loss per year per unit area b. Calculate the corresponding minimum corrosion current per unit area needed to stop corrosion by assuming iron corrodes as Fe Fe2+2e Why is the resistance to stress corrosion cracking sometimes more important than the resistance to uniform corrosion?

Answer 1

Density s(ci 27.6 x W Reaaosim m DxA xT Reaaosim D AxT 9. t8 Oo127 x 7.67 9 ts Art Cmxh A.L A A.W A.t nF iH) o.0llq x 2x16500 55 8 A 31.46

0.0 5 x 1 x 63. 5 2xq4500 O.059 Lloijht Lhen CaThodic a minimum oight minimum Anоани increa Se to anodi zed Aluminim allow on d to yesistana Cnosion improved lubriation not increaSe te doe S dieng Strengt the aluminium object he anodic ayen tHuwe ano non Gondu ctive VOISSOA Tensile Yesidul stresg pregeat lfhen tha ncrele envitonment it gneratas rosive expожd to ondols late . CYaks

53 4 x oW DxA xt Cmpy) Laight loss (mg) Lleight gain y DensiC) ATea ch Sample (in^) A = Exprugure time . (h) While design material into patiulr applicat n We have know thal tis mual s CAOS ivn res is tant patilar evirun ment Cej n et CPR CEaoosim penetratin vte) <20 MPy matoal wgoad cJ0Sim P o tection malhods unifam Cathodic protetin protection Anodic alsb propcodtg Inhibitis