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  1. Provenance of code.
  2. Purpose of code.
  3. Specification.
  4. Description of program's operation.
  5. References.
  6. Parameter descriptions.
  7. Error indicators.
  8. Accuracy estimate.
  9. Any additional information.
  10. Example of code
  11. Auxiliary routines required.
  12. Keywords.
  13. Download source code.
  14. Links.

Provenance of Source Code

Jeevan Jaidi
Research Scholar,
Mechanical Engineering Department,
Indian Institute of Science, Bangalore 560012,

E-mail: jaidi@mecheng.iisc.ernet.in

Added to MAP: August 2000.

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The code calculates the average grain size in the absence of alloying elements/precipitates (free grain growth). This code has been written for a continuous arc welding application, where the thermal history consists of heating and cooling periods. Here, the temperature is transient. The code can also be used for the average grian size calculations in the presence of stabe alloying elements/precipitates or growing precipitates or dissolving precipitates by modifying the rate equation. The maximum average grain size depends on the peak temperature of the thermal cycle.

The rate of change of average grain size in the case of free growth is expressed

by the following equation:

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Product form:

Source code

Complete program.

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  1. .] O. M. Akselsen, O. Grong, N. Ryum, and N. Christensen, Acta Metall. 34 (1986) 1807-1815.
  2. M. F. Ashby and K. E. Easterling, Acta Metallurgica, 30 (1982) 1969-1978.
  3. J. Oystein Grong, Metallurgical Modelling of Welding, 2nd edition, published by the Insitute of Materials, London.

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Input parameters


 DT is a real array containing the time in seconds, G0 is the initial average grain size in micrometers, ISTART is an integer (the Nth starting data point for heating or cooling period ) IEND is an integer (the Nth ending data point for heating or cooling period), LL is an integer describing the number of data points, M0 or Mo* are real and represent the physical parameter related to the grain boundary mobility in units of square micrometers per second, n is a real number representing the time exponent (0.5), QG (or Qapp ) are real numbers representing the activation energy for grain growth in Joules per mole, R is a real number representing the universal gas constant in Joules per mole per Kelvin, T is a real array containing the temperature in Kelvin.


Output parameters

G is a real array giving the average grain size in micrometers

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Error Indicators

The ISTART and IEND for heating/cooling periods must be given correctly. Otherwise the consequence is inexact temperatures during interpolation.



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No information supplied.

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Further Comments


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1. Program text

Complete program.

2. Program data

  See file ags1.in 

3. Program results

  See file ags1out.m 

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Auxiliary Routines

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Average grain size, peak temperature, thermal cycle.

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Download source code

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MAP originated from a joint project of the National Physical Laboratory and the University of Cambridge.

MAP Website administration / map@msm.cam.ac.uk

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