<prompt> Chromium added to steel does notIncrease hardnessIncrease tensile strengthIncrease corrosion resistanceDecrease elastic limit  <response>: Chromium forms a very thin, transparent, adherent layer of Cr2O3 through a process called passivation, which provides a barrier to diffusion of oxygen and other corrosive species and it prevents further corrosion of the underlying alloy.Ref: Phillips 12th edition page 127. 