Per: Andre augusto de araujo Vilar (Swiss Steel do Brasil), andreas mohr (deutsche edelstahlwerke), horst hill (DEUTSCHE EDELSTAHLWERKE), janosch conrads (DEUTSCHE EDELSTAHLWERKE), karlheinz hoeren (DEUTSCHE EDELSTAHLWERKE), philipp niederhofer (DEUTSCHE EDELSTAHLWERKE), leandro akira tochiro (swiss steel group)
Abstract:
Stainless austenitic steels are widely applied in the field of classic mechanical engineering. An important representative of these grades is the material 1.4404 (316L), which is well established as a standard steel in Additive Manufacturing (AM). Typical stainless austenites contain some main alloying elements, which are described in the following: The formation of an austenitic microstructure is achieved by nickel (Ni). The addition of chromium (Cr) lead to the corrosion resistance of these materials. For resistance to localized corrosion, molybdenum (Mo) can be added. However, this requires full dissolution of Cr and Mo in the steel matrix. As a consequence, stainless austenites usually exhibit very low carbon and nitrogen contents to prevent chromium carbides and nitrides. But, both alloying elements cannot be classified as being detrimental in stainless austenites in general. In contrast, C and N can also be used to improve mechanical and chemical properties.
Based on this knowledge, a high-strength austenite was developed particularly tailored for AM. The mechanical properties of the new development, determined by tensile tests, show twice as high characteristic values (yield strength, Rp0.2, and ultimate tensile strength, Rm) compared to 316L, with simultaneously increased corrosion resistance against chloride ions.