Stainless Steel Passivation at an Ambient Temperature

Question:
Is it possible to use Citrajet at ambient temperature (20 deg C) for stainless steel passivation and if so how much time would the process require?

Answer:
Our typical recommendation for stainless steel passivation is to use 20% Citrajet for 120 minutes at 50 deg C. Since stainless steel passivation follows first order reaction kinetics, in theory decreasing the temperature by 30 deg C, from 50 deg C down to 20 deg C, you would need 8 times as much time, or 960 minutes. In principle, every 10 deg C decrease in temperature from optimal doubles the length of time needed.