[Anodorhynchus-hyacinthinu]

Hello friends, good afternoon!
For working with acetic acid, which is the most suitable material based on its degree of corrosion: Molten Fe or High Silicon Fe?
What could be a good justification?

[Enthalpy]

Welcome!

I understand "molten Fe" as cast iron. "High silicon Fe" could be transformer steel or maybe spring steel. Right?

Neither cast iron, transformer steel nor spring steel suit acetic acid. For a short time and if the acid is dilute, maybe. But corrosion will discolour the metal and pollute the acid.

[Anodorhynchus-hyacinthinu]

Thank you!

Actually, I was thinking of a compound like Fe-6.5wt%Si high silicon steel.

I was also thinking about phase diagrams, but that won't help.

Do you know more about the degree of corrosion? Are these values calculated experimentally? Do you know any bibliography broached that?

Thank you again!

[Enthalpy]

Corrosion is strictly experimental. Previsions don't work. Unfortunately, I never used such a steel. Silicon is often claimed to improve the corrosion behaviour of already good steel, but alone Si in Fe won't make stainless steel.

Would you tell what your 6.5% Si steel is? I know mechanical steel up to 1.8% only (for springs) and transformer steel with 3% Si. Is it brittle? Can it be forged? How difficult is the heat treatment? What advantages? Is it transformer steel from NKK?

I fear this steel is uncommon, so data must be scarce. Ask the manufacturer, or make your experiments.

In my experience, 3% Si transformer steel is far from brilliant. Water corrodes it quickly.