<prompt> Which of the following decrease with strain hardening?Surface hardnessStrengthProportional limitCorrosion resistance  <response>: CORROSION RESISTANCE OF AUSTENITIC STAINLESS STEELThe surface of stainless steel is highly prone to oxidation, but its passive surface oxide film blocks significant oxygen diffusion to the underlying alloy, thus limiting further oxidation. Nonetheless, stainless steel can corrode under certain conditions. Severe strain hardening produces highly stressed regions that are anodic to less stressed regions in the presence of saliva. Organic or inorganic deposits and any site of surface roughness on metal may result in localized concentrations of cell corrosion. Thus, corrosion resistance decreases with strain hardening.Reference: PHILLIPS SCIENCE OF DENTAL MATERIALS, 12th ed page no 407 