Materials Algorithms Project
Program Library

Subroutine MAP_STEEL_TIM

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: May 1999.

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Purpose

To calculate the time taken for the fusion zone of a steel weld deposit to cool from T₁ to T₂.

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Specification

 SUBROUTINE MAP_STEEL_TIM(C1,C2,TIME,HIGHT,LOWT,CURR,
&                                   VOLT,EFF,VELOC,TINT)

 DOUBLE PRECISION C1,C2,TIME,HIGHT,LOWT,CURR,VOLT,EFF
 DOUBLE PRECISION VELOC,TINT

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Description

MAP_STEEL_TIM calculates the time taken for the fusion zone of a steel weld deposit to cool from T₁ to T₂ using the equation:

(equation 1(c) in reference 1), where Q is the heat input (Jm^-1) (determined by the welding current, welding voltage and welding speed), eta is the arc weld efficiency and T_i is the interpass temperature (°C). The heat constants C₁ and C₂ are derived by fitting the experimental cooling curve with the equation:

(equation 1(b) of reference 1),where dT/dt is the cooling rate. This equation has been shown to represent accurately the experimental cooling curve from manual metal arc and submerged arc welds over the temperature range 800 to 500 °C. Values for C₁ and C₂ were determined by fitting this equation to a large data-set from many different welds [1]:

These values for C₁ and C₂ can be used to predict the expected cooling curve. See also MAP_STEEL_COOLCU.

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References

1. L.-E. Svensson, B. Gretoft and H.K.D.H. Bhadeshia, Scandinavian Journal of Metallurgy, 15, (1986), 97-103.

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Parameters

Input parameters

C1 - real

C1 is the heat constant C₁ described above.

C2 - real

C2 is the heat constant C₂ described above.

HIGHT - real

HIGHT is the start temperature T₁ (°C).

LOWT - real

LOWT is the stop temperature T₂ (°C).

CURR - real

CURR is the welding current (Amps).

VOLT - real

VOLT is the welding voltage (Volts).

EFF - real

EFF is the arc transfer efficiency.

VELOC - real

VELOC is the welding speed (ms^-1).

TINT - real

TINT is the interpass or preheat temperature (°C).

Output parameters

TIME - real

TIME is the time taken to cool from T₁ to T₂ (seconds).

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Error Indicators

None.

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Accuracy

See reference 1.

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Further Comments

None.

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Example

1. Program text

      DOUBLE PRECISION C1,C2,TIME,HIGHT,LOWT,CURR
      DOUBLE PRECISION VOLT,EFF,VELOC,TINT
      WRITE(*,*)
      WRITE(*,*) 'Input initial and final temperatures:'
      READ (*,*) HIGHT,LOWT
      WRITE(*,*) 'Input heat constants C1 and C2:'
      READ (*,*) C1,C2
      WRITE(*,*) 'Input welding current, voltage and efficiency:'
      READ (*,*) CURR,VOLT,EFF
      WRITE(*,*) 'Input welding speed and interpass temperature:'
      READ (*,*) VELOC,TINT
      CALL MAP_STEEL_TIM(C1,C2,TIME,HIGHT,LOWT,CURR,VOLT,EFF,
     &                                                    VELOC,TINT)
      WRITE (*,1) HIGHT,LOWT,TIME
    1 FORMAT(/'Time taken to cool from ',F6.1,' to ',F6.1,
     &       ' deg. C =',F10.3,' seconds.')
      STOP
      END

2. Program data

 Input initial and final temperatures:
        806         611
 Input heat constants C1 and C2:
       1324.8       1.6
 Input welding current, voltage and efficiency:
        180          34          0.775
 Input welding speed and interpass temperature:
      0.004         200

3. Program results

Time taken to cool from  806.0 to  611.0 deg. C =     8.377 seconds.

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Auxiliary Routines

None.

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Keywords

steel, weld, cooling, time, heat constant

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Download

Download source code

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