Evaluation of single crystal elastic constants and stacking fault energy in high-nitrogen duplex stainless steel by in-situ neutron diffraction

AbstractTransformation induced plasticity (TRIP) leads to enhancements in ductility in low stacking fault energy (SFE) alloys, however to achieve an unconventional increase in strength simultaneously, there must be barriers to dislocation motion. While stacking faults (SFs) contribute to strengthening by impeding dislocation motion, the contribution of SF strengthening to work hardening during deformation is not well understood; as compared to dislocation slip, twinning induced plasticity (TWIP) and TRIP. Thus, we used in-situ neutron diffraction to correlate SF strengthening to work hardening behavior in a low SFE Fe40Mn20Cr15Co20Si5 (at%) high entropy alloy, SFE ~ 6.31 mJ m−2. Cooperative activation of multiple mechanisms was indicated by increases in SF strengthening and γ-f.c.c. → ε-h.c.p. transformation leading to a simultaneous increase in strength and ductility. The present study demonstrates the application of in-situ, neutron or X-ray, diffraction techniques to correlating SF strengthening to work hardening.

Download Full-text

Microstructure evolution of stainless steel subjected to biaxial load path changes: In-situ neutron diffraction and multi-scale modeling

International Journal of Plasticity ◽

10.1016/j.ijplas.2019.06.006 ◽

2019 ◽

Vol 122 ◽

pp. 49-72 ◽

Cited By ~ 3

Author(s):

Manas V. Upadhyay ◽

Jan Capek ◽

Tobias Panzner ◽

Helena Van Swygenhoven

Keyword(s):

Stainless Steel ◽

Neutron Diffraction ◽

Microstructure Evolution ◽

Load Path ◽

Multi Scale ◽

Scale Modeling ◽

Biaxial Load ◽

Multi Scale Modeling ◽

In Situ Neutron Diffraction

Download Full-text

On the Development of Grain-Orientation-Dependent and Inter-Phase Stresses in a Super Duplex Stainless Steel under Uniaxial Loading

Materials Science Forum ◽

10.4028/www.scientific.net/msf.524-525.917 ◽

2006 ◽

Vol 524-525 ◽

pp. 917-922 ◽

Cited By ~ 4

Author(s):

Ru Lin Peng ◽

Yan Dong Wang ◽

Guo Cai Chai ◽

Nan Jia ◽

Sten Johansson ◽

...

Keyword(s):

Plastic Deformation ◽

Stainless Steel ◽

Neutron Diffraction ◽

Grain Orientation ◽

Super Duplex Stainless Steel ◽

Lattice Strains ◽

Duplex Steel ◽

In Situ Neutron Diffraction ◽

Phase Stresses

Microstresses due to intergranular and inter-phase interactions in an austenitic-ferritic super duplex steel (SAF 2507) under uniaxial compressive deformation have been studied by in-situ neutron diffraction experiments. Lattice strains of several hkl planes of austenite respective ferrite were mapped as a function of sample direction at a number of load levels during loading into the plastic regime and unloading. The analysis of the experimental results has shown that during loading both grain-orientation-dependent and inter-phase stresses were generated under plastic deformation that was inhomogeneous at the microstructural level. Residual stresses depending on the grain-orientation and phase have been found after unloading. The results also indicate stronger intergranular interactions among the studied hkl planes of austenite than those of ferrite.

Download Full-text