Effect of Cold Mechanical Process on the Mechanical Properties of 316L Stainless Steel for Medical Implant Application

Abstract

The objective of this research was to study the mechanical properties of cold-worked 316L stainless steel (SS) after it has undergone the cold mechanical process. A 316L SS sheet was cold-rolled until a reduction in thickness was within the range of 10% to 50%. The sheet was then plastically deformed into a U-bend shape using a universal testing machine equipped with a bending jig. The mechanical properties of the cold-rolled and U-bend steel were analysed using a tensile, 3-point bending, and microhardness tests. It was found that the rolling and bending processes produced such amount of plastic strain that affect the mechanical properties of the 316L SS. The strength of the cold-rolled, U-bend 316L SS increased gradually as the cold reduction was raised above 10%, which was mainly due to the strain hardening effects. The ultimate strength of the U-bend steel increased gradually compared to the cold-rolled steel for each stage of the cold reduction process. On the other hand, the microhardness of the U-bend steel increased rapidly after a cold reduction up to 10%, and the value increased slightly after a cold reduction of 30%. This study indicated that the mechanical properties of 316L SS can be increased by using a combination of the cold rolling and bending processes.