THERMODYNAMIC SIMULATIONS USING THERMO- CALC, DICTRA AND TC-PRISMA SOFTWARE

Transcription

1 1 THERMODYNAMIC SIMULATIONS USING THERMO- CALC, DICTRA AND TC-PRISMA SOFTWARE Timo Juuti Materiaalitekniikan Laboratorio / Timo Juuti

2 2 CONTENTS INTRODUCTION THERMO-CALC FUNCTIONALITY + EXAMPLES DICTRA FUNCTIONALITY + EXAMPLES TC-PRISMA FUNCTIONALITY + EXAMPLES SIMULATION USING BOTH TC AND PRISMA Materiaalitekniikan Laboratorio / Timo Juuti

3 THERMO-CALC AT MATERIALS ENGINEERING LABORATORY 3 Thermo-Calc Windows (TCW) DICTRA TC-PRISMA TQ Software Development Kit TCFE: TCS Steels / Fe-alloys SSUB: SGTE Substances SSOL: SGTE Solutions SLAG: TCS Fe-containing slag SOFTWARE DATABASES TCOX: TCS Oxide solution NOX: NPL Oxide solutions MOBFE: TCS Fe-alloys mobility MOB: TCS Alloys mobility Materiaalitekniikan Laboratorio / Timo Juuti

4 4 THERMO-CALC FUNCTIONALITY Calculations of multicomponent thermodynamics and phase diagrams Calculations based on thermodynamic database CAN BE USED TO CALCULATE: Stable and meta-stable heterogeneous phase equilibria Amounts of phases and their compositions Thermochemical data such as enthalpies, heat capacity and activities Transformation temperatures, such as liquidus and solidus Driving force for phase transformations Phase diagrams (binary, ternary and multi-component) Solidification applying the Scheil-Gulliver model Thermodynamic properties of chemical reactions Materiaalitekniikan Laboratorio / Timo Juuti

5 5 THERMO-CALC EXAMPLES Fe-C binary phase diagram Phase Diagrams for multicomponent systems Ternary Phase diagrams Materiaalitekniikan Laboratorio / Timo Juuti

6 6 DICTRA FUNCTIONALITY DIffusion Controlled TRAnsformations in multi-component alloy systems Linking fundamental models to thermodynamic and kinetic data Same databases as with Thermo-Calc One dimensional simulations, with 3 geometries CAN BE USED TO CALCULATE: Microsegregation during solidification Homogenization of alloys Growth / Dissolution of carbides, nitrides and intermetallic phases Coarsening of precipitate phases Austenite to ferrite transformations Carburization and Decarburizationa of steel Materiaalitekniikan Laboratorio / Timo Juuti

7 7 DICTRA EXAMPLES Dissolution of carbides Darken experiment (joint of two steels with initially similar C content but different Si content. Si increases C activity causing carbon to diffuse to the right. Discontinuity in C is seen at the gradient in silicon content) Materiaalitekniikan Laboratorio / Timo Juuti

8 8 PRISMA FUNCTIONALITY Treats concurrent nucleation, growth / dissolution, and coarsening under arbitrary heat treatment conditions Multi-component & Multi-phase system! Uses Langer-Schwartz theory and Kampmann-Wagner numerical approach INPUT Composition Temperature Simulation time Thermodynamic Data Kinetic data Property data (int.energy, volume etc.) Nucleation sites and related microstructure information TC-PRISMA OUTPUT Particle size distribution Number density Average particle radius Volume fraction Matrix composition Precipitate composition Nucleation rate Critical radius TTP diagrams TIEDEKUNTA TIEDEKUNTA / osasto osasto osaston osasto Materiaalitekniikan / Etuniminen Laboratorio / Timo Juuti Sukuniminen-Sukuniminen

9 9 TC-PRISMA EXAMPLES Volume fraction vs time TTP curve TIEDEKUNTA TIEDEKUNTA / osasto osasto osaston osasto Materiaalitekniikan / Etuniminen Laboratorio / Timo Juuti Sukuniminen-Sukuniminen

10 10 CASE EXAMPLE Calculation to observe the effect of different cooling rates (15 C/s 90 C/s) to the amount of free interstitial atoms in the matrix on ferritic stainless steel. Thermo-Calc TIEDEKUNTA TIEDEKUNTA / osasto osasto osaston osasto Materiaalitekniikan / Etuniminen Laboratorio / Timo Juuti Sukuniminen-Sukuniminen

11 11 CASE EXAMPLE Volume fraction of M 23 C 6 carbides after different cooling rates from 925 C. 45 C/s 30 C/ s 15 C / s Faster cooling leads to more free carbon in matrix 90 C/s Discontinuous yielding / dynamic strain aging etc. TIEDEKUNTA TIEDEKUNTA / osasto osasto osaston osasto Materiaalitekniikan / Etuniminen Laboratorio / Timo Juuti Sukuniminen-Sukuniminen

12 12 THANK YOU Timo Juuti Materiaalitekniikan Laboratorio / Timo Juuti