restart & Austenite formation

solid-solid phase transformations, influence of stresses and strains
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Jane
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Joined: Tue Mar 29, 2022 1:06 pm
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restart & Austenite formation

Post by Jane » Fri May 13, 2022 9:37 am

Dear Bernd,

I have some questions about austenite formation that I need to consult with you, and I hope you can kindly give me some advice.

Next, I will describe my simulation process:
① Firstly, I simulated the phase transition from austenite to acicular ferrite, and took it as the initial structure of my next simulation (restart the initial structure is shown in Figure 1).
② After restarting step ①, I prepared to nucleate austenite in the acicular ferrite grain and grain boundary, that is, the formation of austenite.

However, the following problems appeared in the process of simulation:
(1) Why does the initial structure of reactivation evolve all the time, that is, acicular ferrite grows up uniformly (FIG. 2)?
② Nucleation is not in accordance with the situation I set, and there is no change, only the acicular ferrite continues to grow up, equivalent to still is austenite ferrite phase transition.
I have attached my driver file, do you have any suggestions? I am looking forward to your reply.

Jane

#
# Automatic 'Driving File' written out by MICRESS.
#
# MICRESS binary
# ==============
# version number: 7.000 (Linux)
# compiled: 11/13/2019
# compiler version: Intel 1600 20160811
# executable architecture: x64
# Thermo-Calc coupling: enabled
# Version: 21
# Link Date: 14-11-2018 09:10:32
# OS Name: Linux
# Build Date:
# Compiler: ifort (IFORT) 16.0.4 20160811
# OpenMP: disabled
# shell: /bin/tcsh
# ('double precision' binary)
#
#
# Language
# ========
# Please select a language: 'English', 'Deutsch' or 'Francais'
English
#
#
# Output Location
# ===============
# Options: [ <directory path>/ ] <base name>
# The default result directory is the driving file location.
Results_Acicular_restart/cooling_restart_heating
# Overwrite files with the same name?
# Options: overwrite write_protected append
# [zipped|not_zipped|vtk]
# [unix|windows|non_native]
overwrite
#
#
# Restart
# =======
# Restart using old results?
# Options: new restart [reset_time | with_flow]
new reset_time
#
#
# Geometry
# ========
# Grid size?
# (for 2D calculations: CellsY=1, for 1D calculations: CellsX=1, CellsY=1)
# Cells in X-direction (CellsX):
250
# Cells in Y-direction (CellsY):
1
# Cells in Z-direction (CellsZ):
250
# Cell dimension (grid spacing in micrometers):
# (optionally followed by rescaling factor for the output in the form of '3/4')
0.2500000
#
#
# Model
# =====
# Type of coupling?
# Options: phase concentration [volume_change] temperature temp_cyl_coord
# [stress{U|CE|MC}{1|2|3}] [flow] [flow_coarse] [dislocation]
concentration
# Thermal Conditions
# Options: no_lat_heat no_lat_heat_dsc lat_heat 1d_temp [kin. Coeff.]
# kin. Coeff: Kinetics of latent heat release (default is 0.01)
no_lat_heat
#
#
# Boundary Conditions
# ===================
# Boundary conditions for phase field in each direction
# Options: i (insulation) s (symmetric) p (periodic/wrap-around)
# g (gradient) f (fixed) w (wetting)
# Sequence: W E (S N, if 3D) B T borders
# (X: West-East, Y:South-North, Z:Bottom-Top)
pppp
#
# Boundary conditions for concentration field in each direction
# Options: i (insulation) s (symmetric) p (periodic/wrap-around) g (gradient) f (fixed)
# Sequence: W E (S N, if 3D) B T borders
pppp
#
# Unit-cell model symmetric with respect to the x/y diagonal plane?
# Options: unit_cell_symm no_unit_cell_symm
no_unit_cell_symm
#
#
# Database
# ========
# Is a thermodynamic database to be used?
# Options: database database_verbose database_consistent no_database
database GES_Files/FeCMn
#
# Which global relinearisation interval shall be used?
# Options: manual from_file none
manual
# Relinearisation interval [s]
1.0000
# Reading GES5 workspace ...
#
#
# Components
# ==========
# Type of concentration?
# Options: atom_percent (at%)
# weight_percent (wt%)
weight_percent
#
# The database contains the following components:
# 1: C
# 2: FE
#
# A component can be specified by an element symbol,
# user defined name or database index.
# 'end_of_components' will finish the components input.
# Component 0 (main component) ?
2
# Component 1 ?
1
# Component 2 ?
3
# Component 3 ?
end_of_components
#
# MICRESS component indexing
# 0 -> FE (database)
# 1 -> C (database)
#
#
# Phases
# ======
#
# Selection of Phases
# -------------------
# The database contains 5 phases:
# 1: LIQUID
# 2: BCC_A2
# 3: CEMENTITE_D011
# 4: FCC_A1
#
# A phase can be specified by the name or index used in the database
# or by a user defined name.
# 'end_of_phases' will finish the phase data input.
#
# Name or database index of phase 0 (matrix phase)
1
# Name or database index of phase 1
4
# Name or database index of phase 2
2
# Name or database index of phase 3
end_of_phases
#
# MICRESS phase indexing
# 0 -> LIQUID (database)
# 1 -> FCC_A1 (database)
# 2 -> BCC_A2 (database)
#
# Input/Output Format for Orientations
# ------------------------------------
# How shall grain orientations be defined?
# Options: angle_2d euler_zxz angle_axis miller_indices quaternion
angle_2d
#
#
# Phase Properties
# ----------------
#
# Phase 0 ( LIQUID )
# ------------------
# Type of molar volume input ?
# Options: constant [temp_extrapol] [conc_extrapol]
constant
# Value of molar volume ? ([cm**3/mol])
10.0
#
# Phase 1 ( FCC_A1 )
# -------------------
# Simulation of recrystallisation in phase 1 (PHASE_1) ?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 1 (FCC_A1) anisotropic ?
# Optionen: isotropic anisotropic faceted_a faceted_b faceted[_c] antifaceted
anisotropic
# Crystal symmetry of phase 1 (FCC_A1) ?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Should grains of phase 1 (FCC_A1) be reduced to categories?
# Options: categorize no_categorize
no_categorize
# Type of molar volume input ?
# Options: constant [temp_extrapol] [conc_extrapol]
constant
# Value of molar volume ? ([cm**3/mol])
10.0
#
# Phase 2 ( BCC_A2 )
# -------------------
# [identical phase number]
# Simulation of recrystallisation in phase 2 (PHASE_2) ?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 2 (BCC_A2) anisotropic ?
# Optionen: isotropic anisotropic faceted_a faceted_b faceted[_c] antifaceted
anisotropic
# Crystal symmetry of phase 2 (BCC_A2)?
# Options: none cubic hexagonal tetragonal orthorhombic
tetragonal
# Should grains of phase 2 (BCC_A2) be reduced to categories?
# Options: categorize no_categorize
no_categorize
# Type of molar volume input ?
# Options: constant [temp_extrapol] [conc_extrapol]
constant
# Value of molar volume ? ([cm**3/mol])
10.0
#
#
#
# Phase Interactions
# ==================
# Start legacy mode by entering keyword 'phase_interaction' or 'no_phase_interaction'.
# Start terse mode with 2 phase IDs and keyword 'phase_interaction' in one line.
# Finish terse mode input with 'end_phase_interactions'.
#
# 0 (LIQUID) / 1 (FCC_A1)
# --------------------------
# Simulation of interaction between 0 (MATRIX) and 1 (PHASE_1) ?
# Options: phase_interaction no_phase_interaction
# [ standard | particle_pinning[_temperature] | solute_drag ]
# | [ redistribution_control ] or [ no_junction_force | junction_force ]
no_phase_interaction
#
# 0 (LIQUID) / 2 (BCC_A2)
# --------------------------
# Simulation of interaction between 0 (MATRIX) and 2 (PHASE_2) ?
# Options: phase_interaction no_phase_interaction identical phases nb
# [ standard | particle_pinning[_temperature] | solute_drag ]
# | [ redistribution_control ] or [ no_junction_force | junction_force ]
no_phase_interaction
#
# 1 (FCC_A1) / 1 (FCC_A1)
# ---------------------------
# Simulation of interaction between 1 (PHASE_1) and 1 (PHASE_1) ?
# Options: phase_interaction no_phase_interaction identical phases nb
# [ standard | particle_pinning[_temperature] | solute_drag ]
# | [ redistribution_control ] or [ no_junction_force | junction_force ]
phase_interaction
# Type of interfacial energy definition between 1 (PHASE_1) and 1 (PHASE_1) ?
# Options: constant temp_dependent
constant
# Interfacial energy between 1 (PHASE_1) and 1 (PHASE_1) ? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
1.00000E-05
# Type of mobility definition between PHASE_1 and PHASE_1?
# Options: constant temp_dependent dg_dependent [fixed_minimum]
constant
# Kinetic coefficient mu between PHASE_1 and PHASE_1 [cm**4/(Js)] ?
5.00000E-06
# Shall misorientation be considered?
# Options: misorientation no_misorientation
# [low_angle_limit (degrees)] default:15 [special_orient (nb)]
no_misorientation
#
# 1 (FCC_A1) / 2 (BCC_A2)
# ---------------------------
# Simulation of interaction between 1 (FCC_A1) and 2 (BCC_A2) ?
# Options: phase_interaction no_phase_interaction identical phases nb
# [ standard | particle_pinning[_temperature] | solute_drag ]
# | [ redistribution_control ] or [ no_junction_force | junction_force ]
phase_interaction redistribution_control
# 'DeltaG' options: default
# avg ...[] max ...[J/cm^3] smooth ...[Deg] noise ...[J/cm^3] offset ...[J/cm^3]
avg 0.5 smooth 20
# I.e.: avg +0.50 smooth +20.0
# Type of interfacial energy definition between 1 (PHASE_1) and 2 (PHASE_2) ?
# Options: constant temp_dependent
constant
# Interfacial energy between 1 (FCC_A1) and 2 (BCC_A2) ? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
5.0000E-05 5.0000E-04
# Type of mobility definition between FCC_A1 and BCC_A2?
# Options: constant temp_dependent dg_dependent [fixed_minimum]
constant
# Kinetic coefficient mu between FCC_A1 and BCC_A2 [cm**4/(Js)] ?
5.00000E-04
# Shall misorientation be considered?
# Options: misorientation no_misorientation
# [low_angle_limit (degrees)] default:15 [special_orient (nb)]
misorientation low_angle_limit 0 special_orient 2
# Input of the special orientation relation Nb 1
# Rotation angle? [tolerance] (in degrees)
45. 0.1
# Prefactor of interfacial energy for the special OR:
0.30000
# Prefactor of interfacial mobility for the special OR?
1.0000
# Input of the special orientation relation Nb 2
# Rotation angle? [tolerance] (in degrees)
0. 360.
# Prefactor of interfacial energy for the special OR:
1.0000
# Prefactor of interfacial mobility for the special OR?
0.0000
# Is interaction isotropic?
# Options: isotropic
# anisotropic [junction_force] [harmonic_expansion]
# aniso_special_orient [junction_force][harmonic_expansion]
anisotropic
# This anisotropic interaction is not yet implemented.
# Instead: isotropic-metallic
# Anisotropy of interfacial stiffness? (tetragonal)
# (1 - delta * (4*(nx^4 +nz^4) -3)
# * (1-nz^2 +nz^2*faktor)
# Coefficient delta (<1.), factor z/x (>0)? (2 REALS)
0.05 2.
# Anisotropy of interfacial mobility? (tetragonal)
# (1 + delta * (4*(nx^4 +nz^4) -3)
# * (1-nz^2 +nz^2*faktor)
# Coefficient delta (<1.), factor z/x (>0)? (2 REALS)
0.05 0.02
# Which phase diagram is to be used?
# Options: database [local|global[F]|globalG[F]] [start_value_{1|2}]
# linear linearTQ
database global
# Relinearisation interval for interface FCC_A1 / BCC_A2
# Options: automatic manual from_file none
none
# Please specify the redistribution behaviour of each component:
# Format: forward [backward]
# Options: nple para paratq normal [mob_corr] atc [mob_corr] [verbose]
# Component C:
normal mob_corr
# Component MN:
nple
#
#
# 2 (BCC_A2) / 2 (BCC_A2)
# -------------------------
# Simulation of interaction between 2 (BCC_A2) and 2 (BCC_A2) ?
# Options: phase_interaction no_phase_interaction identical phases nb
# [ standard | particle_pinning[_temperature] | solute_drag ]
# | [ redistribution_control ] or [ no_junction_force | junction_force ]
no_phase_interaction
# Type of interfacial energy definition between 2 (BCC_A2) and 2 (BCC_A2) ?
# Options: constant temp_dependent
# constant
# Interfacial energy between 2 (BCC_A2) and 2 (BCC_A2) ? [J/cm**2]
# [max. value for num. interface stabilisation [J/cm**2]]
# 1.00000E-05
# Type of mobility definition between BCC_A2 and BCC_A2?
# Options: constant temp_dependent dg_dependent [fixed_minimum]
constant
# Kinetic coefficient mu between BCC_A2 and BCC_A2 [cm**4/(Js)] ?
5.00000E-06
# Shall misorientation be considered?
# Options: misorientation no_misorientation
# [low_angle_limit (degrees)] default:15 [special_orient (nb)]
misorientation low_angle_limit 15
# Input of the misorientation coefficients:
# Modification of interfacial energy for low angle boundaries
# Options: factor read-shockley
factor
# Prefactor of interfacial energy for low angle boundaries?
0.50000
# Modification of the mobility for low angle boundaries
# Options: factor humphreys [min_reduction + parameters B and N
# (default: min_reduction=0. B=5.0 N=4.0)]
factor
# Prefactor of interfacial mobility for low angle boundaries?
0.10000
# Please specify a criterion for the choice
# of the direction of the redistribution model:
# Options: local_velocity average_velocity bottom_temperature
average_velocity
#
#
# Diffusion
# =========
# ["Terse Mode": Each line starts with component number and phase number]
# Options: diagonal|diagonal_dilute [x] multi|multi_plus [y(1..k)]
# x: one of the characters "n", "d", "g", "l", "z", "i", "I", or "f"
# y: chain of "n", "d", "g", "l", "z", or "f" (for each component)
# default: "g" resp. "gggg..."
# Rem: "n":no diffusion, "d": input, "f": T-dep. from file
# "i":infinite, "I": infinite in each grain
# from database: "g": global, "l": local, "z" global z-segmented
# Extra line option: [+b] for grain-boundary diffusion
# Extra line option (prefactor on time step): cushion <0-1>
# Extra line option: infinite_limit_[d|t] (in cm**2/s|K)
# Extra line option: maxfactor_local [real > 1.0] (default: 10.0)
# Extra line option: factor [real > 0.]
# Extra line option: dilute [real >= 0.] (default:1.0)
# Finish input of diffusion data with 'end_diffusion_data'.
#
# How shall diffusion of component Comp_1 in phase MATRIX be solved?
diagonal n
# How shall diffusion of component Comp_1 in phase PHASE_1 be solved?
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
0.23400
# Activation energy? (real) [J/mol]
1.47700E+05
# How shall diffusion of component Comp_1 in phase PHASE_2 be solved?
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
0.12300
# Activation energy? (real) [J/mol]
98290.
# How shall diffusion of component MN in phase LIQUID be solved?
diagonal n
# How shall diffusion of component MN in phase FCC_A1 be solved?
# multi gg
# How shall diffusion of component MN in phase BCC_A2 be solved?
# multi gg
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
0.23400
# Activation energy? (real) [J/mol]
1.47700E+05
# How shall diffusion of component Comp_2 in phase PHASE_2 be solved?
diagonal d
# Diff.-coefficient:
# Prefactor? (real) [cm**2/s]
0.12300
# Activation energy? (real) [J/mol]
98290.
#
#
# How shall the interval for updating diffusion coefficients
# data be set?
# Options: constant from_file
# constant
# Interval for updating diffusion coefficients data? [s]
# 1.01
#
# Initial Microstructure
# ======================
# Type of grain positioning?
# Options: deterministic random [deterministic_infile] from_file
deterministic
# NB: the origin of coordinate system is the bottom left-hand corner,
# all points within the simulation domain having positive coordinates.
# Number of grains at the beginning?
0
#
#
# Structure from restart file
# ---------------------------
# Shall grain(s) be replaced by initial structure(s) from a restart file(s) ?
# Options: restart_file | no_restart_file
restart_file
# How many restart files shall be read?
1
# For each restart file a grain number and (optionally)
# shift (in grid cells) and zoom factor for all 3 dimensions
# as well as a character for rotation options must be specified:
# grain number [shift X (int) shift Y (int) shift Z (int)
# zoom X (int) zoom Y (int) zoom Z (int) rot(string)] ?
# Rotation options: "xz+90" "xz-90" "xz180" "xy+90" ... "yz180"
0 0 0 0 1 1 1
# Name of restart file?
Acicular_t_3
#
# Initial Concentrations
# ======================
# How shall initial concentrations be set?
# Options: input equilibrium from_file [phase number]
equilibrium 1
# Initial concentration of component 1 (C) in phase 1 ? [wt%]
0.10000
# Initial concentration of component 2 (MN) in phase 1 (FCC_A1) ? [wt%]
1.5
# Temperature at which the initial equilibrium
# will be calculated? [K]
# 1100
900
# 650
#
#
# Process Conditions
# ==================
#
# Temperature
# -----------
# Type of temperature trend?
# Options: linear linear_from_file profiles_from_file
linear
# Number of connecting points? (integer)
0
# Initial temperature at the bottom? (real) [K]
900
# Temperature gradient in z-direction? [K/cm]
0.0000
# Cooling rate? [K/s]
2
#
# 1D far field for solute diffusion
# ---------------------------------
# Enable one dimensional far field approximation for solute diffusion?
# Options: 1d_far_field 1d_far_field_EW no_1d_far_field
no_1d_far_field
#
# Moving frame
# ------------
# Moving-frame system in z-direction?
# Options: moving_frame no_moving_frame
no_moving_frame
#
#
# Nucleation
# ==========
# Enable further nucleation?
# Options: nucleation nucleation_symm no_nucleation [verbose|no_verbose]
nucleation
# Additional output for nucleation?
# Options: out_nucleation no_out_nucleation
no_out_nucleation
#
# Number of types of seeds?
2
#
# Input for seed type 1:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple front [restrictive]
bulk
# Phase of new grains (integer) [unresolved|add_to_grain|split_from_grain]?
1
# Reference phase (integer) [min. and max. fraction (real)]?
2
# Which nucleation model shall be used?
# Options: seed_undercooling seed_density [ lognormal_1 | lognormal_2 ]
seed_undercooling
# Maximum number of new nuclei of seed type 3?
# (set negative for unlimited number)
200
# Grain radius [micrometers]?
# 0.0000
0.5
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
55.000
# Determination of nuclei orientations?
# Options: random randomZ fix range parent_relation
parent_relation
# Minimal value of rotation angle? [Degree]
45.000
# Maximal value of rotation angle? [Degree]
45.000
# Shield effect:
# Shield time [s] [shield phase or group number] ?
100
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
5.
# Nucleation range
# min. nucleation temperature for seed type 3 [K]
800
# max. nucleation temperature for seed type 3 [K]
1500
# Time between checks for nucleation? [s]
# Options: constant from_file
constant
# Time interval [s]
# 1.0000
0.01
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
nucleation_noise
# Factor for random noise?
# (applied as DeltaT -> (1+Factor*(RAND-1/2))*DeltaT)
1.00000E-02
#
# Input for seed type 2:
# ----------------------
# Type of 'position' of the seeds?
# Options: bulk region interface triple quadruple front [restrictive]
interface restrictive
# Phase of new grains (integer) [unresolved|add_to_grain|split_from_grain]?
1
# Reference phase (integer) [min. and max. fraction (real)]?
2
# Substrate phase [2nd phase in interface]?
# (set to 2 to disable the effect of substrate curvature)
2
# Maximum number of new nuclei of seed type 2?
# (set negative for unlimited number)
200
# Grain radius [micrometers]?
# 0.0000
0.5
# Choice of growth mode:
# Options: stabilisation analytical_curvature
stabilisation
# min. undercooling [K] (>0)?
50
# Determination of nuclei orientations?
# Options: random randomZ fix range parent_relation
random
# Shield effect:
# Shield time [s] [shield phase or group number] ?
500
# Shield distance [micrometers] [ nucleation distance [micrometers] ]?
2
# Nucleation range
# min. nucleation temperature for seed type 2 [K]
800
# max. nucleation temperature for seed type 2 [K]
1500
# Time between checks for nucleation? [s]
# Options: constant from_file
constant
# Time interval [s]
0.01
# Shall random noise be applied?
# Options: nucleation_noise no_nucleation_noise
no_nucleation_noise
#
# Seed for random-number generator initialisation
# -----------------------------------------------
777777777
#
# Max. number of simultaneous nucleations?
# ----------------------------------------
# (set to 0 for automatic)
0
#
# Shall metastable small seeds be killed?
# Options: kill_metastable no_kill_metastable
kill_metastable
#
#
# Output
# ======
#
# Output times
# ------------
# Finish input of output times (in seconds) with 'end_of_simulation'
# 'regularly-spaced' outputs can be set with 'linear_step'
# or 'logarithmic_step' and then specifying the increment
# and end value
# ('automatic_outputs' optionally followed by the number
# of outputs can be used in conjuction with 'linear_from_file')
# 'first' : additional output for first time-step
# 'end_at_temperature' : additional output and end of simulation
# at given temperature
linear_step 0.1 2
linear_step 1.0 30
end_of_simulation
#
# Output files
# ------------
# Selection of the outputs
# [legacy|verbose|terse]
# Finish selection of outputs with 'end_of_outputs'.
terse
out_restart
out_grains
out_phases
out_fraction 1 2
tab_fractions
out_interface
out_driv_force
tab_grains
out_conc
out_mobility
tab_lin
tab_log 1.
out_orientation
tab_orientation [rotmat]
# out_relin
# out_curvature
# out_velocity
# tab_vnm
# tab_grain_data
# out_temp
# out_conc_phase
# tab_conc
# out_recrystall
# tab_recrystall
# out_disloc
# out_miller
end_of_outputs
#
#
# Numerical parameters
# ====================
#
# Phase field solver
# ------------------
# Time-step ?
# Options: fix ...[s] automatic automatic_limited
automatic_limited
# Options: constant from_file
constant
# Limits: (real) min./s, [max./s], [time step factor], [segregation factor]
1.E-4 1.0
#Coefficient for phase-field criterion 1.00
#Coefficient for segregation criterion 0.900
#Number of steps to adjust profiles of initially sharp interfaces [exclude_inactive]?
20
# Type of potential?
# Options: double_obstacle multi_obstacle [no_fd_correction | fd_correction]
# Recommended: multi_obstacle fd_correction
multi_obstacle fd_correction
# Phase minimum?
1.00E-04
# Interface thickness (in cells)?
3.5000
# Coefficient for initial dimension of field iFace
# [minimum usage] [target usage]
0.1
# Coefficient for initial dimension of field nTupel
# [minimum usage] [target usage]
0.1
#
# Concentration solver
# --------------------
# Factor for diffusion time stepping? (0.0 < factor < 1.0)
0.95000
#
# List of phases and components which are stoichiometric:
# phase and component(s) numbers
# List of concentration limits (at%):
# <limits>, phase number and component number
# List of penalty conditions:
# <penalty>, phase 1, phase2, component number
# List for ternary extrapolation (2 elements + main comp.):
# <interaction>, component 1, component 2
# Switches: <stoich_enhanced_{on|off}> <solubility_{on|off}>
# List of relative criteria on phase composition
# <criterion_higher | criterion_lower>, phase No 1, phase No 2, component No
# List of sublattice order conditions:
# <ordered|disordered>, phase , sublattice 1, sublattice 2
# List of source changes for diffusion data
# <switch_diff_data>, Phase-No., reference phase
# Switch: Add composition sets for calculation of diffusion/volume/enthalpy data
# <diff_comp_sets | vol_comp_sets | enth_comp_sets>, phase list
# End with 'no_more_stoichio' or 'no_stoichio'
no_stoichio
#
#
#
#
Attachments
FIG 1.png
FIG 1.png (111.96 KiB) Viewed 4125 times
FIG 2.png
FIG 2.png (98.67 KiB) Viewed 4125 times

Bernd
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Re: restart & Austenite formation

Post by Bernd » Fri May 13, 2022 1:29 pm

Dear Jane,

Why do you expect growth of ferrite not to continue after restart, if you are still cooling down further? And why should austenite nucleate if the driving force goes into direction of ferrite growth?

Bernd

Jane
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Re: restart & Austenite formation

Post by Jane » Sat May 14, 2022 3:11 am

Dear Bernd,

I understand what you're saying, but I've changed the cooling rate to a positive number here, so shouldn't that mean heating? Or is my initial temp too low? So what am I supposed to do? Hope to get your help. I will be very grateful.

Jane

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Re: restart & Austenite formation

Post by Jane » Sun May 15, 2022 3:26 pm

Dear Bernd,

I looked up basically all the posts in the forum about this heating and saw your reply that just need to change the new phase and the reference in the nucleation process to be equal, I did that too, but the result is like I said , so I didn't find any other way to solve this problem, I hope you can help me out of your busy schedule, I will be very grateful.

Jane

Bernd
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Re: restart & Austenite formation

Post by Bernd » Mon May 16, 2022 5:07 pm

Dear Jane,

Your are right: Your are heating and not cooling, I overlooked that. So, if you start from a too ow temperature, then it takes some time for the heating to take effect. Do you observe that the system changes from further ferrite growth to austenite growth after some time (>~100 s)? Then, nucleation should also work (as long as there is some ferrite left).

Of course, you could just start from a higher temperature. Finally, this depends on the question, which process you aim to model this 2-step-simulation.

Bernd

Jane
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Re: restart & Austenite formation

Post by Jane » Tue May 17, 2022 3:20 am

Dear Bernd,

Thanks for the reply you took out of your busy schedule, yes the nucleation didn't happen even with the simulation time increasing, even though the nucleation temperature was high, and I had to do a two-step simulation, if you need the first driver file I will send it to you.

Jane

Bernd
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Re: restart & Austenite formation

Post by Bernd » Tue May 17, 2022 2:02 pm

Dear Jane,

your second seed type for nucleation of austenite is directed to ferrite/ferrite-grain boundaries, while the first one should get active inside the bulk region of the ferrite grains. But please bear in mind that nucleation will occur only where austenite is not present before by default. This means, that there may remain little space for nucleation after subtracting all the austenite/ferrite-interface regions...

If you explicitly want to include austenite nucleation even on ferrite/austenite-interfaces you should define austenite as first or second substrate phase in the definition of the nucleation types.

If you are unsure about whether nucleation works correctly or not, you should try using the general "verbose" nucleation option. Then MICRESS will tell you how many points have been checked and how many have been discarded for different reasons.

Bernd

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