Determination of Johnson-Cook Constitutive and Failure Parameters for Cr20Ni80 Alloy Using an Experimental-Numerical...

Area of Science:

• Materials Science
• Mechanical Engineering
• Computational Modeling

Background:

• Accurate numerical simulations of Cr20Ni80 alloy processing require robust constitutive and failure models.
• Existing models may not fully capture the alloy's behavior under diverse conditions.

Purpose of the Study:

• To experimentally and numerically calibrate and validate the Johnson-Cook (J-C) constitutive and failure parameters for Cr20Ni80 alloy.
• To ensure the reliability of simulations for alloy processing.

Main Methods:

• Conducted quasi-static tensile tests on smooth and notched specimens.
• Performed dynamic Split Hopkinson Tension Bar (SHTB) tests at strain rates of 1000-3000 s⁻¹ with pulse-shaping.
• Utilized an experimental-numerical approach to determine J-C parameters.

Main Results:

• Calibrated constitutive parameters (A, B, n, C) and failure parameters (D1, D2, D3, D4).
• Confirmed negligible thermal softening due to adiabatic heating.
• Achieved good agreement between simulated and experimental stress-strain curves.

Conclusions:

• The calibrated J-C model reliably predicts the mechanical response of Cr20Ni80 alloy.
• The validated parameters enhance the accuracy of numerical simulations for alloy processing.