| Abstract Scope |
The development of hydrogen-resistant steels depends on understanding alloy composition and microstructure evolution during deformation. We analyzed the 21Cr-6Ni-9Mn (Nitronic 40) alloy and a series of four developmental alloys in which the Ni/Mn ratio is varied. The Ni/Mn balance can affect several critical materials parameters including stacking fault energy, slip-induced twinning and dislocation splitting. We probe the relationship between deformation and microstructure using tensile testing and nanoindentation tests. Conospherical indentations allow TEM lift-out samples in which the stress state of the lift-out can be determined. Therefore, a relationship between stress and microstructure can be drawn. Interrupted strain tests serve to compare an initial plastic microstructure between the alloys to determine dislocation density, burgers vector and stacking fault energy. How these microstructural aspects vary between alloys and in the presence of hydrogen are of importance in understanding the role of composition and embrittlement in the deformation microstructure. |