Metal finishing Q&As since 1989

-----

Nitric Acid attack on Carbon Steel

I will be designing some equipment which will occasionally see aggressive wash downs with CO2, detergents & 0.10M Nitric Acid & then rinsed with water.

I would like to avoid stainless steel on this project due to the size (& cost) of these components (several 40" diameter x 5' long wire rope drums). Is there any research published on the web which would document the corrosive effects of a diluted acid (0.1M Nitric) on A572 steel (or similar).

Would electroplating/galvanizing be a cost effective option as opposed to stainless steel in the event that the carbon steel would not hold up to 0.1M Nitric Acid ?

Any help would be wonderful !

Thanks !
Jeremy

Jeremy Kuhn
- Lancaster, Pennsylvania, USA
2003

Any carbon or alloy steel will be severely damaged by nitric acid even at low concentration. Also copper and its alloys are not an option. Examples of "low cost" metals that resist are aluminum and chrome. Both can be applied to steel either by plating or thermospraying but need to be made impervious (i.e. cracks or pores absolutely have to be sealed with suitable sealant to avoid penetration of acid to base steel).

Guillermo Marrufo
Monterrey, NL, Mexico
2003