Program MAPSTEELANREC



1. Provenance of Source Code


 

C. Capdevila and H.K.D.H. Bhadeshia, Phase Transformations Group, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, U.K.



 E-mail: cc226@cus.cam.ac.uk




 Added to MAP: Octuber 2000. 

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2. Purpose

 

A model incorporating nucleation and growth theory was used to describe the volume fraction of recrystallisation as a function of deformation and the heating rate. Observed variations in the recrystallisation temperature and the nucleation rate have been found to be consistent with the assumption that anything which introduces heterogeneity into the microstructure stimulates recrystallisation. 
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3. Specification

1.45in
0.5in Language: 

FORTRAN 77
0.5in Product form: 

Source code
0.5in

 Complete program.

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4. Description


 

Recrystallisation in commercial MA-ODS alloys occurs at very high temperatures close to melting, in spite of their large stored energy [1-3]. This is unlike conventional alloys which recrystallise at much lower homologous temperatures [4]. It could be argued that recrystallisation is inhibited by the fine yttria dispersoids. However, this is inconsistent with experimental observations which indicate an insensitivity of the recrystallisation temperature to variations in the overall pinning force. Indeed, the limiting grain size in the presence of particles is far greater than the starting grain size. 

 



where  is a shape factor,  is the nucleation rate and  is the grain-boundary velocity. Each unrecrystallised grain has a number of faces, which may bulge. Empirical expressions for  and  has been considered.

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5. References



0.5in 1.  W. Sha and H. K. D. H. Bhadeshia, 1994, Metall. Mater. Trans. A, 25, p.705.

0.5in 2. K. Murakami, K. Mino and H. K. D. H. Bhadeshia, 1993, Metall. Trans. A, 24, p.1049.

0.5in 3. S. Chou and H. K. D. H. Bhadeshia, 1993, Mater. Sci. Technol., 9, p.890.

0.5in 4. A. Cotrell, 1975, 'An Introduction to Metallurgy', Eds. E. Arnold, London, p.402.

0.5in 5. P. Jongenburger and R. F. Singer, 1989, 'New Materials by Mechanical Alloying Techniques',  Ed: E. Artz and L. Schultz, DGM- Infomationsgesellschaft, Obeerusel, p.157.

0.5in 6.W. Sha and H. K. D. H. Bhadeshia, 1997, Mater. Science and Engineer., A223,p.91.

0.5in 7.H. Regle and A. Alamo, 1993, Journal of Physique IV, C7 3,p.169.

0.5in 8.J. W. Christian, 1975, 'Theory of Transformations in Metals and Alloys', Part I,p.545.

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6. Parameters

 Input parameters



 HR - double precision

 Heating Rate (C/min.).



 TM - double precision

 Melting Temeprature (C).



 DEFLEVEL - double precision

 Deformation level (



 R - double precision

 Gas constant (J K mol).



 FREQ - double precision

 Vibration frequency (s).



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 Output parameters



 CTEMP - double precision

 Temperature (C).



 RECRYS - double precision

 Recrystallisation volume fraction ().



 NUCL - double precision

 Nucleation Rate per unit volume (m s).



 VEL - double precision

 Grain boundary velocity (m s).


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7. Error Indicators

 

None.

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8. Accuracy

 

No information supplied.

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9. Further Comments

 

None.

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10. Example

 10.1 Program text

 Complete program.

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 10.2 Program data




 TM=1482D+00
 R=8.1416D+00
 FREQ=1.3D+09



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 10.3 Program results




     CTEMP           RECRYS            NUCL                VEL

      850.        .000000E+00        .000000E+00        .315194E-13
      860.        .000000E+00        .000000E+00        .549784E-13
      870.        .000000E+00        .000000E+00        .949683E-13
      880.        .000000E+00        .000000E+00        .162498E-12
      890.        .000000E+00        .000000E+00        .275490E-12
      900.        .000000E+00        .130345E+23        .462867E-12
      910.        .000000E+00        .146652E+23        .770898E-12
      920.        .000000E+00        .164673E+23        .127299E-11
      930.        .669982E-03        .184553E+23        .208463E-11
      940.        .532497E-02        .206444E+23        .338613E-11
      950.        .345463E-01        .230509E+23        .545674E-11
      960.        .197643E+00        .256920E+23        .872574E-11
      970.        .103564E+01        .285857E+23        .138481E-10
      980.        .502177E+01        .317512E+23        .218162E-10
      990.        .215891E+02        .352087E+23        .341225E-10
     1000.        .668685E+02        .389794E+23        .529969E-10
     1010.        .992220E+02        .430854E+23        .817487E-10
     1020.        .999945E+02        .475503E+23        .125256E-09
     1030.        .999986E+02        .523985E+23        .190666E-09
     1040.        .999998E+02        .576557E+23        .288383E-09
     1050.        .100000E+03        .633488E+23        .433460E-09
     1060.        .100000E+03        .695057E+23        .647549E-09
     1070.        .100000E+03        .761558E+23        .961615E-09
     1080.        .100000E+03        .833296E+23        .141968E-08
     1090.        .100000E+03        .910587E+23        .208401E-08
     1100.        .100000E+03        .993763E+23        .304214E-08
 


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11. Auxiliary Routines


None
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12. Keywords

 

ODS, steel, ferritic steel, recrystallisation 



