Which of the following decrease with strain hardening?
CORROSION RESISTANCE OF AUSTENITIC STAINLESS STEEL
The 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
Surface hardness
Strength
Proportional limit
Corrosion resistance