INVESTIGATION OF MICROSTRUCTURE OF CYCLICALLY CRYOGENICALLY TREATED SPECIMENS OF SS316L AND COMPARISON OF ITS MECHANICAL PROPERTIES WITH CYCLICALLY HEAT TREATED SPECIMENS USING IN AN AUTOMOBILES

Subject to a continuing debate, cryogenic treatments of alloy steels have been claimed to significantly increase wear resistance and toughness through the interplay of three effects: completing martensitic transformation, promoting uniform precipitation of fine carbides and imparting residual stresses. This study reexamines effects of various heat-treatment schedules including cyclic heat treatment at (690 C) and cyclic cryogenic(Shallow) treatment at (-85 C) onmicrostructure and selected properties of Stainless steel 316L.Examination methods include SEM,, micro hardness, Charpy impact, wear resistance measured using the standard pin-on-disk technique adopted from the field of thin-film technologies. Results confirm the cryo-treatment enhanced precipitation in the subsequent tempering step of what turns out to be 100-250 nm alloydepleted carbides, and moderate improvements in wear resistance and hardness, both scaling with the cryogenic treatment time and at the cost of reduced impact resistance and also corrosion resistance. Reported results and correlations shows that it is mainly suitable for automobile industries