About Alexandre Guimarães Botelho Expertise General questions about metallurgy. Metals, fabrication processes, physical metallurgy, chemical composition and physical properties.
As my area of expertise is corrosion, fracture and extractive metallurgy, I may not respond quickly to more in-depth questions outside those fields.
Experience Up to the moment (2008) I have five years of experience in maintenance and inspection of industrial equipment, integrity assessment, reliability and failure analysis. I also have previous experience in iron mine processing unit and pelletizing process units.
Organizations PETROBRAS-Brazilian energy enterprise
Publications 9th COTEQ - Conferência sobre tecnologia de Equipamentos, 6 SIC - Simpósio Internacional de Confiabilidade, 2nd CIM - Seminário de Confiabilidade, Inspeção e Manutenção da PETROBRAS.
Education/Credentials I have technical degree in mechanics and graduation as a Metallurgical Engineer. I am also specialized in industrial equipment, maintenance and inspection, and currently specializing in Quality Engineering and Reliability Engineering.
Question I'm doing a science project and I need to know which metals are most commonly used in construction. I plan to place them in salt water and see which oxidizes the fastest. Thanks for your time. I would really appreciate it if this was answered ASAP, but of course, beggars can't be choosers. Thanks again.
Answer Dear Naomi,
That will depend on the segment. For oil&gas, we use mostly low and medium carbon steel, and stailess steels of grades 300 and 400.
Since you plan to test in salt water, you may try an excellent example by Pourbaix. Wrap a common 304 stainless steel plate (such steel used for cooking pans) with a rubber band (such as used for money) so as to stretch the band across it. Leave it inside salt water and see what happens to the so called "corrosion proof" steels.
Usually, carbon steels corrode faster on salt water, but that depends on how is corrosion important to you. For pressure vessels, a wall loss is as important as a small bore made by pitting corrosion, since it breaks the vessels containment.
Also, for salt water use with low oxygen, carbon steel with 5% Cr content is used for some applications.
