Mechanical and Electrochemical Characterization of Super-Solidus Sintered Austenitic Stainless Steel (316L)

摘要

The present study compares the mechanical and electrochemical behaviour of austenitic (AISI 316L) stainless steel compacted at various pressures (200, 400 and 600 MPa) and conventionally sintered at super-solidus temperature of 1,400℃. The electrochemical behaviour was investigated in 0.1 N H_2SO_4 solution by poten-tiodynamic polarization and electrochemical impedance spectroscopy (EIS). The shrinkage decreased and densifi-cation has been increased with increasing pressure. The mechanical and electrochemical behaviour with pressure has been correlated with densification response and microstructure (pore type, volume and morphology). Highest densification (～92% theoretical) achieved at 600 MPa (compaction pressure) and l,400℃ (sintering temperature) resulted in excellent combination of tensile strength and ductility (456 ± 40 MPa, 25 ± 1.1%), while showing excellent corrosion resistance (0.1 mmpy or 4.7 mpy).