Materials Algorithms Project
Program Library

Subroutine MAP_STEEL_PARTIC

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

Provenance of Source Code

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

Added to MAP: August 1999.

Top | Next

Purpose

For a steel weld it calculates (a) the distribution of oxygen among the constituent elements Si, Al, Ti and Mn, (b) the amount of Ti tied up by N and (c) the amount of B in solution and the amount tied up by N.

Top | Next | Prev

Specification

 SUBROUTINE MAP_STEEL_PARTIC( ALTOT,ALSOL,OXYWT,OXYMIN,TITOT,
&           PEROAL,PEROTI,PEROMN,PEROSI,PERTIN,PERTIO,PERBSL,
&           PERBN,IFAIL,NITWT,NITSOL,BWT,STATE,FBORT )

 DOUBLE PRECISION ALTOT,ALSOL,OXYWT,OXYMIN,TITOT,PEROAL,PEROTI
 DOUBLE PRECISION PEROMN,PEROSI,PERTIN,PERTIO,PERBSL,PERBN,NITWT
 DOUBLE PRECISION NITSOL,BWT,STATE,FBORT

 INTEGER IFAIL

Top | Next | Prev

Description

The subroutine divides up any oxygen and nitrogen present in the weld between the elements Al, Ti, B, Mn and Si in the following way:

• All of the Al present reacts with oxygen to form Al₂O₃.
• Any remaining oxygen reacts with Ti to form either TiO, Ti₂O₃ or TiO₂. (The oxidation state of the Ti oxide to be formed must be supplied as an input parameter to the subroutine.)
• If there is insufficient oxygen to tie up all of the Ti in this way, then the remaining Ti reacts to form TiN.
• Any remaining N reacts with B to form BN:
  If there are more atoms of B than N, then all of the N is assumed to react with the boron and the remaining B goes into solution. If there are more atoms of N than B, the amount of B staying in solution is calculated from the equation
  
  log([%B][%N]) = 5.24 - 13970/T
  
  (See equations 9 and 10 in reference 2); the rest of the B forms BN.
• Any remaining N goes into solution.
• Any remaining O is divided up between Mn and Si, using the result obtained by Evans [3] that SiO₂ and MnO form in the ratio of 1.64:1 by weight.

The oxidation state of the titanium oxide formed must be specified through the input parameter, STATE, as follows:
  STATE = 2.0   if the oxide of titanium is assumed to be TiO₂.
  STATE = 1.5   if the oxide of titanium is assumed to be Ti₂O₃.
  STATE = 1.0   if the oxide of titanium is assumed to be TiO.

Top | Next | Prev

References

1. T.W. Lau, M.M. Sadowski, T.H. North, G.C. Weatherly, 1988, Mat. Sci. & Tech, 4, 52-61.
2. W. Fountain and J. Chapman, Trans. Met. Soc. AIME, 1962, 224, 599-606.
3. G.M. Evans, 1991, Welding Journal, 70, 32-39.

Top | Next | Prev

Parameters

Input parameters

ALTOT - real

ALTOT is the total aluminium concentration (wt.%).

ALSOL - real

ALSOL is the dissolved aluminium concentration (wt.%).

OXYWT - real

OXYWT is the total oxygen concentration (wt.%).

TITOT - real

TITOT is the total titanium concentration (wt.%).

NITWT - real

NITWT is the total nitrogen concentration (wt.%).

BWT - real

BWT is the total boron concentration (wt.%).

STATE - real

Set STATE to 1, 1.5 or 2 for the formation of TiO, Ti₂O₃, or TiO₂ respectively.

FBORT - real

FBORT is the temperature (Kelvin) at which the boron solubility product is to be evaluated.

Output parameters

OXYMIN - real

OXYMIN is the minimum amount of oxygen (wt.%) that is required to oxidise all of the aluminium and titanium.

PEROAL - real

PEROAL is the percentage of oxygen (% moles) tied up with aluminium.

PEROTI - real

PEROTI is the percentage of oxygen (% moles) tied up with titanium.

PEROMN - real

PEROMN is the percentage of oxygen (% moles) tied up with manganese.

PEROSI - real

PEROSI is the percentage of oxygen (% moles) tied up with silicon.

PERTIN - real

PERTIN is the percentage of titanium (% moles) tied up with nitrogen.

PERTIO - real

PERTIO is the percentage of titanium (% moles) tied up with oxygen.

PERBSL - real

PERBSL is the percentage of boron (% moles) which is in solution.

PERBN - real

PERBN is the percentage of boron (% moles) tied up with nitrogen.

IFAIL - integer

IFAIL=1 if the amount of oxygen present is insufficient to tie up aluminium.

NITSOL - real

NITSOL is the amount of nitrogen in solution (ppm by weight).

Top | Next | Prev

Error Indicators

IFAIL = 1 if the amount of oxygen present is insufficient to tie up aluminium,
IFAIL = 0 otherwise.

Top | Next | Prev

Accuracy

No information supplied.

Top | Next | Prev

Further Comments

None.

Top | Next | Prev

Example

1. Program text

      DOUBLE PRECISION ALTOT,ALSOL,TITOT,PEROAL,PEROTI,PEROMN,
     &      PEROSI,PERTIN,PERTIO,PERBSL,PERBN,NITWT,NITSOL,BWT,STATE,
     &      FBORT,OXYWT,OXYMIN
      INTEGER IFAIL
C
      STATE = 1.5
      WRITE(*,*)
      WRITE(*,*) 'Input total and dissolved Al concentrations (wt%):'
      READ (*,*) ALTOT,ALSOL
      WRITE(*,*) 'Input total O and total Ti concentrations (wt%):'
      READ (*,*) OXYWT,TITOT
      WRITE(*,*) 'Input total N and total B concentrations (wt%):'
      READ (*,*) NITWT,BWT
      WRITE(*,*) 'Input temperature for evaluating B solubility (K):'
      READ (*,*) FBORT
      CALL MAP_STEEL_PARTIC(ALTOT,ALSOL,OXYWT,OXYMIN,TITOT,PEROAL,
     &            PEROTI,PEROMN,PEROSI,PERTIN,PERTIO,PERBSL,PERBN,
     &            IFAIL,NITWT,NITSOL,BWT,STATE,FBORT)
      IF (IFAIL.NE.0) 
     &         WRITE (*,*) 'Insufficient oxygen to oxidise the Al.'
      WRITE (*,1) OXYMIN
      WRITE (*,2)
      WRITE (*,3) 'Aluminium',PEROAL
      WRITE (*,3) 'Titanium ',PEROTI
      WRITE (*,3) 'Manganese',PEROMN
      WRITE (*,3) 'Silicon  ',PEROSI
      WRITE (*,4) PERTIN 
      WRITE (*,5) PERTIO
      WRITE (*,6) PERBSL
      WRITE (*,7) PERBN
      WRITE (*,8) NITSOL
      STOP
    1 FORMAT (//'Minimum oxygen content required to oxidise '
     &          'Al & Ti completely =',F8.4,' wt%')
    2 FORMAT ( / 1H ,9H Element ,5X,15H% of the oxygen )
    3 FORMAT ( 4(1H ,A9,10X,F6.2) )
    4 FORMAT (/' Percentage of Ti tied up with N = ', F6.2)
    5 FORMAT (  ' Percentage of Ti tied up with O = ', F6.2)
    6 FORMAT (/' Percentage of B in solution = ', F6.2)
    7 FORMAT (  ' Percentage of B as BN       = ', F6.2)
    8 FORMAT (/' Amount of nitrogen in solution =',F7.2,' ppmw'/)
      END

2. Program data

 Input total and dissolved Al concentrations (wt%):
 0.02 0.005
 Input total O and total Ti concentrations (wt%):
 0.03 0.02
 Input total N and total B concentrations (wt%):
 0.01 0.002
 Input temperature for evaluating B solubility (K):
 940

3. Program results

Minimum oxygen content required to oxidise Al & Ti completely =  0.0234 wt%

  Element      % of the oxygen
 Aluminium           44.47 
 Titanium            33.40 
 Manganese            4.54 
 Silicon             17.58 

 Percentage of Ti tied up with N =   0.00
 Percentage of Ti tied up with O = 100.00

 Percentage of B in solution =   3.53
 Percentage of B as BN       =  96.47

 Amount of nitrogen in solution =  75.00 ppmw

Top | Next | Prev

Auxiliary Routines

None.

Top | Next | Prev

Keywords

weld, oxide, nitride, solubility, inclusions

Top | Next | Prev

Download

Download source code

Top | Prev