Corrosion Terminology - X,Y,Z's

yield point—the stress on a material at which the first significant permanent or plastic deformation occurs without an increase in stress. In some materials,particularly annealed low-carbon steels, there is a well-defined yield point from the straight line defining the modulus of elasticity.

yield strength—the stress at which a material exhibits a specified deviation from the proportionality of stress to strain. The deviation is expressed in terms of strain by either the offset method (usually at a strain of 0.2 percent) or the total-extension-under-load method (usually at a strain of 0.5 percent).

zeta potential—see electrokinetic potential.