Evaluation of Mechanical Properties of Stainless Steel Microelements Manufactured by Electrical Discharge Machining

Abstract

To evaluate the mechanical properties of microelements made of semi-austenitic precipitation hardening stainless steel, SUS631,tensile and tension-tension fatigue tests were conducted in laboratory air. Specimens were manufactured using a high precision electrical discharge machining. R_<max> of the finished machining surface was 1&acd;2 μm. The tensile strength of transverse specimens was larger than that of longitudinal ones. However no influence of rolling direction on fatigue strength was observed. Some inclusions were observed on the fracture surface, and the fatigue crack initiated there.