Materials Algorithms Project
Program Library

Subroutine MAP_STEEL_NITMMA

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: September 1999.

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Purpose

To calculate the nitrogen concentration in manual metal arc welds.

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Specification

 SUBROUTINE MAP_STEEL_NITMMA(C,SI,MN,NI,MO,CR,V,AL,TI,CO,NB,TA,W,
&                            ZR,CU,NITPPM,HEAT,IFAIL)

 DOUBLE PRECISION C,SI,MN,NI,MO,CR,V,AL,TI,CO,NB,TA,W,ZR,CU
 DOUBLE PRECISION NITPPM,HEAT
 INTEGER IFAIL

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Description

MAP_STEEL_NITMMA calculates the nitrogen concentration, N_c, in manual metal arc welds using the equation:

where F is the activity coefficient of the steel and H_t is the electrical heat input to the weld [1].

The activity coefficient [3] is a factor which accounts for the influence of alloying elements on the solubility of nitrogen in dilute liquid steel. It is calculated from the concentrations (wt. %) of C, Si, Mn, Ni, Mo, Cr, V, Al, Ti, Co, Cu, Nb, Ta, W, and Zr present in the steel weld by calling MAP_STEEL_NITR. If any of the input values for the concentrations of C, Si, Mn, Ni, Mo, Cr, or V, are greater than certain specified limits, beyond which the nitrogen calculation is uncertain, then the value for the upper limit is used in the calculations. The input variables, however, remain unchanged on exit from the subroutine. It is assumed that Al, Ti, Co, Cu, Nb, Ta, W, and Zr are present as trace elements only.

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References

1. H.K.D.H. Bhadeshia, unpublished work.
2. H.K.D.H. Bhadeshia, L.-E. Svensson and B. Gretoft, 1988, Journal of Materials Science Letters, 7, 610-612.
3. See MAP_STEEL_NITR.

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Parameters

Input parameters

C - real

C is the carbon concentration (weight percent). Upper limit for C is 0.2 wt%.

SI - real

SI is the silicon concentration (weight percent). Upper limit for Si is 0.8 wt%.

MN - real

MN is the manganese concentration (weight percent). Upper limit for Mn is 2.0 wt%.

NI - real

NI is the nickel concentration (weight percent). Upper limit for Ni is 3.0 wt%.

MO - real

MO is the molybdenum concentration (weight percent). Upper limit for Mo is 1.0 wt%.

CR - real

CR is the chromium concentration (weight percent). Upper limit for Cr is 1.0 wt%.

V - real

V is the vanadium concentration (weight percent). Upper limit for V is 0.5 wt%.

AL - real

AL is the dissolved aluminium (weight percent).

TI - real

TI is the dissolved titanium (weight percent).

CO - real

CO is the dissolved cobalt (weight percent).

NB - real

NB is the dissolved niobium (weight percent).

TA - real

TA is the dissolved tantalum (weight percent).

W - real

W is the dissolved tungsten (weight percent).

ZR - real

ZR is the dissolved zirconium (weight percent).

CU - real

CU is the dissolved copper (weight percent).

HEAT - real

HEAT is the electrical heat input to the weld (Jm^-1).

Output parameters

NITPPM - real

NITPPM is the nitrogen content of the weld metal (parts per million by weight).

IFAIL - integer

IFAIL = 1 on exit if any of the concentrations of C, Si, Mn, Ni, Mo, Cr, or V exceed the specified limits. IFAIL = 0 otherwise.

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Error Indicators

IFAIL = 1 on exit if any of the concentrations of C, Si, Mn, Ni, Mo, Cr, or V exceed the specified limits.
IFAIL = 0 otherwise.

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Accuracy

The typical error is ±20 ppmw.

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Further Comments

If the estimated value for the nitrogen concentration, obtained using the above equation, is less than zero, then it is set to zero.

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Example

1. Program text

      DOUBLE PRECISION AL,TI,CO,NB,TA,W,ZR,CU
      DOUBLE PRECISION C,SI,MN,NI,MO,CR,V,NITPPM,HEAT
      INTEGER IFAIL
C
      WRITE(*,*) 'Input C, Si, Mn, Ni, Mo, Cr, V (wt%):'
      READ (*,*) C, SI, MN, NI, MO, CR, V
      WRITE(*,*) 'Input Al, Ti, Co, Nb, Ta, W, Zr, Cu (wt%):'
      READ (*,*) AL, TI, CO, NB, TA, W, ZR, CU
      WRITE(*,*) 'Give heat input to weld (J/m):'
      READ (*,*) HEAT
      CALL MAP_STEEL_NITMMA(C,SI,MN,NI,MO,CR,V,AL,TI,CO,NB,TA,W,
     &                      ZR,CU,NITPPM,HEAT,IFAIL)
      WRITE (*,1) NITPPM
      IF (IFAIL.EQ.1) 
     &  WRITE(*,*) '**** WARNING **** Input data exceeded limits.'
      STOP
    1 FORMAT(//' Nitrogen content of weld = ',F7.2, ' ppmw')
      END

2. Program data

 Input C, Si, Mn, Ni, Mo, Cr, V (wt%):
    0.05 0.5 1.0 0.0 0.5 0.5 0.0
 Input Al, Ti, Co, Nb, Ta, W, Zr, Cu (wt%):
    0.001 0.0 0.0 0.0 0.01 0.0 0.0 0.0
 Give heat input to weld (J/m):
 1.2E6

3. Program results

 Nitrogen content of weld =   84.57 ppmw

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Auxiliary Routines

Subroutines
MAP_STEEL_NITR

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Keywords

nitrogen, concentration, manual metal arc, weld, activity coefficient

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Download

Download source code

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