The activation polarization required to dissolve 18-8 chromium-nickel stainless steel anodically in 42 wt. % aqueous magnesium chloride solution is reduced by yielding of the metal perpendicular to the direction of dissolution. Yielding at strain rates of about 5%/min or more reduces the activation polarization of 0.18 V required to dissolve static metal at 0.5 A/cm$^2$ to a value, not more than a few mV, experimentally indistinguishable from zero. The effect is found both in the presence of the concomitant concentration polarization in stationary solution, and in its absence in rapidly flowing solution. Yielding assists dissolution probably by increasing the number of active sites on the dissolving surface and perhaps also by reducing the activation energy required for their dissolution. The phenomenon supports the electrochemical theory of the propagation of stress-corrosion cracks in stressed 18-8 type steels exposed to chloride solutions. It has not been found in nickel, titanium or mild steel, which do not suffer stress-corrosion cracking under these conditions.