Novel low-temperature solid-carburizing using C60 fullerene for austenitic stainless steel SUS316L

In this study, the full potential of C60 fullerene for use in the low-temperature solid-carburizing of SUS316L stainless steel is demonstrated. The carburizing of this austenitic stainless steel with C60 was conducted in a vacuum atmosphere without any surface activation treatment of the specimen surfaces. The uncarburized SUS316L had the lattice parameter of approx. 3.5963 ± 0.0001 Å and the Vickers hardness of 172 MPa measured by the Nanoindentation method. After carburizing at 475°C for 200 h, the lattice parameter of the specimen surface was approx. 3.6545 ± 0.0001 Å and the Vickers hardness was approx. 742 MPa. After carburizing at 500°C for 100 h, the lattice parameter of the specimen surface was approx. 3.6592 ± 0.0002 Å and the Vickers hardness was approx. 837 MPa. These results are comparable to those obtained by low-temperature gas- and plasma-carburizing reported in previous works.