Tempered Martensite:
From quenching to mechanical testing
Solutions by Application
- Determine martensite start and finish dependent on the quenching rate.
- Tailor amount and distribution of carbides.
- Optimize the heat treatment for each specific steel grade.
- Determine flow curves of tempered martensite dependent on the heat treatment process.
- Trace all relevant microstructural features during processing and service .
Mechanical properties of steel vary dependent on the heat treatment process. An exceptional examples is tempered martensite where the mechanical properties can be tuned from for high hardness, high strength, wear resistance, and corrosion resistance of the martensitic structure to good ductility and toughness of almost ferritic structure with precipitated carbides. Simulating the evolution of the microstructure “from quenching to fracture” enables you to tailor your process to the required mechanical properties appropriate to the intended use.
OpenPhase capabilites
1- Determine martensite start and finish dependent on the quenching rate:
- Martensite start is predicted on the basis of driving forces to transformation on basis of the alloy thermodynamics of the system.
- Martensite finish is determined on the basis of the transformation kinetics.
- Internal heat release due to transformation is considered.
- Results are transformed to virtual dilatometer curves.
2- Tailor amount and distribution of carbides:
- OpenPhase provides a number of modules for nucleation of carbides, from random statistics to nucleation at dedicated sites, interfaces of junctions, as well as local residual strain.
- The growth stage is determined by the local supersaturation of carbon and relaxation of the tetragonal distortion of the martensitic lattice.
- The ripening stage is determined by multi-component diffusion and cross interaction of the solute elements.
- The effect of lattice strain on diffusion coherency strain and coherency loss during growth can be considered.
3- Optimize the heat treatment for each specific steel grade:
- Investigate the response of the system on different heat extraction conditions.
- Tailor heat extraction by inverse optimization.
- Test nucleation conditions of various populations of carbides and competitive growth.
- Investigate the role of microalloying on precipitation and mechanical stability.
4- Determine flow curves of tempered martensite dependent on the heat treatment process:
- Optimize crystal plasticity models with sparse experimental input.
- Interpolate and extrapolate flow rules to be used in FE analysis of the sample scale.
- Determine rules as function of local alloy composition.
- Tailor the heat treatment process for optimized mechanical response.
5- Trace all relevant microstructural features during processing and service:
- Automatically monitor size and distribution of all elements of the microstructure.
- Apply autocorrelation functions for application specific materials characteristics.
- Provide 3-D information for correlation with 2-D experimental micrographs.
