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Program MAP_STEEL_BORON

  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

Sangeeta Khare

Graduate Institute of Ferrous Technology (GIFT)

Pohang University of Science and Technology (POSTECH)

Pohang 790-784

Republic of Korea

E-mail: skhare@postech.ac.kr

Added to MAP: March 2009.

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Purpose

The program calculates the soluble boron in a steel containing of titanium, aluminium, nitrogen and boron using solubility product equations of nitrides.

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Specification

Language: Fortran
Product form: Source code

Complete program.

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Description

Soluble boron in a steel containing  titanium, aluminium, nitrogen and boron is calculated by stepwise approach  which is based on the solubility product of various nitrides under equilibrium conditions.  Nitrogen combines with that element which forms first according to solubility product equations [1-4]. The temperature at which precipitate form is calculated by assuming total nitrogen can combine with Ti, Al or B and these temperatures are given as T°TiN, T°AlN and T°BN.

It assumes that  Ti, Al & B form nitrides only  and  are in an equilibrium state and follow solubility product equations  as

log [Ti][N] =  -15790 T-1 + 5.4            

log [Al][N] =  -7400 T-1 + 1.95      

log [B][N]  =  -13970 T-1 + 5.24    

 

where the temperatures are  in Kelvin and the terms in square brackets represent dissolved solute concentration in wt%. 

 

From mass balance,

Ti =  TiTiN  +   [Ti]                          

Al =  AlAlN +   [Al] 

B  =  BBN  +   [B]

In general, M = [M] + MMN where 'M' stands for a metal atom and MMN is the amount of that metal atom tied up with nitrogen and the total nitrogen is N =   [N] + NTiN + NAlN + NBN.

By solving the above equations as described in [1], the residual nitrogen can be calculated. The residual nitrogen is then available for the next of two elements to form nitride and accordingly it will combine with the next metal atom forming at the next higher temperature  till any residual nitrogen left otherwise the process stops and soluble boron can be determined.

 The program requires four elements namely  titanium,  boron, aluminium  and  nitrogen (all in wt%) to be supplied.

 Input    order

  Element

 Min.(wt%)  Max.(wt%)
1   Titanium  0.0  0.05
2   Boron  0.0  0.005
3   Aluminium  0.0  2.0
4   Nitrogen  0.0  0.020

The output gives temperature at which each precipitate forms T°TiN, T°AlN and T°BN by allowing whole of nitrogen to combine with Ti, Al and B and the soluble boron at 920 °C in the steel.

The maximum number of alloys that can be examined is set to be 10.

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References

  1. T. Gladman.  The Physical Metallurgy of Microalloyed Steels.  IOM Communications,   London, 1996.

  2.  E. T. Turkdogan. Causes and effects of nitride and carbonitride precipitation during continuous casting.  Iron Steelmaker, 3 : 61-75, 1989. 

  3. L.S. Darken, R.P. Smith and E.W. Filer, Solubility of Gaseous Nitrogen in Gamma Iron and the Effect of Alloying Constituents-Aluminium Nitride Precipitation. Trans AIME. 191 :1174-1179 (1951).

  4.  W.  Fountain  and  J.  Chipman.   Solubility  and  precipitation  of  boron  nitride  in  Fe-B   alloys. Trans.  TMS-AIME, 224 :599-606,  1962.

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Parameters

Input parameters

TIWT- real
Titanium concentration (in weight percent).
BWT - real
Boron concentration (in weight percent).
ALWT - real
Aluminium concentration (in weight percent).
NWT - real
Nitrogen concentration (in weight percent).

Output parameters

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Error Indicators

Allowable range ( see description)

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Accuracy

No information supplied.

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Further Comments

None.

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Example

1. Program text

    Complete program.

2. Program data

         Identification Number ?
	   (zero to exit program)
1
	   Titanium wt.% ?
0.01
	   Boron wt.% ?
0.0028
	   Aluminium wt.% ?
0.003
	   Nitrogen wt.% ?
0.0050


3. Program results
*********************************************************************
       Titanium            = 0.0100 wt%
	   Boron               = 0.0028 wt%
	   Aluminium           = 0.0030 wt%
	   Nitrogen            = 0.0050 wt%
*********************************************************************
	   Temperature for TiN = 1350.C
	   Temperature for BN  = 1110.C
	   Temperature for AlN = 815.C
*********************************************************************
	   Soluble Boron       = 13.9 ppm at 920C
*********************************************************************


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Auxiliary Routines

Subroutines

MAP_SOLUBLE_BORON_CALCULATION

MAP_BN_SOLUBILITY

MAP_TIN_SOLUBILITY

MAP_ALN_SOLUBILITY

MAP_BORON_NITROGEN_ARRAY

MAP_BN_TEMPERATURE

MAP_TIN_TEMPERATURE

MAP_ALN_TEMPERATURE

MAP_CHECK_NITROGEN

MAP_BORON_SOLUBLE

MAP_BOUND

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Keywords

Soluble boron, titanium, aluminium, nitrogen, solubility product.

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Download

Download source code

Download executable for Windows

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