A stainless steels resistance against uniform corrosion in a specific environment is often determined from weight loss measurements performed on coupons immersed in the solution during a relatively short period of time. Often some kind of activation is used to aggravate the test conditions. The purpose of this investigation was to study the influence of two different activation methods (immersion in boiling HCl, and galvanic contact with Zn) on the weight losses measured. In addition, the influence of deaeration compared to free entrance of air and the influence of crevices were studied. The study was performed on high alloy austenitic and duplex stainless steels.

The experimental work included electrochemical measurements, i.e. corrosion potentials were measured during the weight loss measurements and anodic polarisation curves were recorded in solutions with the same composition as in the uniform corrosion tests.

The study shows that the activation method, the degree of aeration and the presence of crevices are all parameters which could have a significant influence on the uniform corrosion rate of a stainless steel in HCl solutions.