# Working with stainless steel in 3 M HCl solution

We are trying to mix a material using 316 stainless steel blades in a $3~\mathrm{M}\ \ce{HCl}$ solution for 4 hours in a PE container? Will the blades stand for 4 hours or do they start to corrode in 4 hours?

• That's quite high concentration. The steel blades wills start to corrode. Better use polymer lined stainless steel or , just go away from steel, and use something made of PE. – ankit7540 Dec 20 '16 at 0:38

The typical corrosion rate in $1\ \%$ hydrochloric acid at room temperature is about $0.1\ \mathrm{mm\ a^{-1}}$, which is approximately $0.1\ \mathrm{g\ m^{-2}\ h^{-1}}$. At higher concentrations or higher temperature, the corrosion rate is strongly increased. Note that your concentration of $c=3\ \mathrm{mol\ l^{-1}}$ $\ce{HCl}$ corresponds to about $10\ \%$ hydrochloric acid.
Furthermore, stainless steel SAE 316 is prone to chloride-induced stress corrosion cracking at elevated temperatures (over about $50\ \mathrm{^\circ C}$).