Energy dissipation and plastic flow instability were investigated in P91 steel and
Ms70 brass on the basis of continuous tests carried out on Setaram and Gleeble plastometers.
Mathematical evaluation of continuous curves was supported with calculation of larger range
of input parameters using the "sin h" equation. For energy dissipation calculation strain rate
sensitivity parameter (m=(d ln σ)/(d ln ė)) was computed and further the efficiency according to
the η=2m/(m+1) formula. Equation ξ=(∂ ln(m/(m+1)))/(∂ ln ė)+m was utilized for the instability
parameter calculation. The results were evaluated using Sigmacon, Gnuplot and Golden Surfer
computer softwares. The final results are 2D and 3D material processing maps. Results of tests
carried out with P91 steel and Ms70 brass were compared to experimental results of other
authors with high correlation.
Keywords: alloys; energy dissipation; flow instability; plastometric tests.
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