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.
To calculate the nitrogen concentration in undiluted submerged arc welds.
Language: | FORTRAN |
Product form: | Source code |
SUBROUTINE MAP_STEEL_NITSUB(C,SI,MN,NI,MO,CR,V,AL,TI,CO,NB,TA, & W,ZR,CU,NITPPM,CURR,NW,IFAIL) DOUBLE PRECISION C,SI,MN,NI,MO,CR,V,AL,TI,CO,NB,TA,W,ZR,CU DOUBLE PRECISION NITPPM,CURR,NW
MAP_STEEL_NITSUB calculates the nitrogen concentration in undiluted submerged arc welds for welding currents of between 450 and 650 Amps. It uses a fit to the results given in reference 1 to obtain an estimate for the nitrogen concentration, Nc, (ppm by weight):
where Iw is the welding current (Amps), Nw is the nitrogen content of the welding wire and F is the activity coefficient of the steel [2].
The activity coefficient 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.
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.
The typical error is ±13 ppmw.
If the estimated value for the nitrogen concentration, obtained using the above equation, is less than zero, then it is set to zero.
DOUBLE PRECISION AL,TI,CO,NB,TA,W,ZR,CU DOUBLE PRECISION C,SI,MN,NI,MO,CR,V,NW,CURR,NITPPM 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(*,*) 'Input nitrogen content of wire (ppmw):' READ (*,*) NW WRITE(*,*) 'Input welding current (Amps):' READ (*,*) CURR CALL MAP_STEEL_NITSUB(C,SI,MN,NI,MO,CR,V,AL,TI,CO,NB,TA,W, & ZR,CU,NITPPM,CURR,NW,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
Input C, Si, Mn, Ni, Mo, Cr, V (wt%): 0.05 0.5 1.0 0.0 0.0 0.5 0.5 Input Al, Ti, Co, Nb, Ta, W, Zr, Cu (wt%): 0 0 0 0 0 0 0 0 Input nitrogen content of wire (ppmw): 50 Input welding current (Amps): 180
Nitrogen content of weld = 89.70 ppmw
nitrogen, submerged arc, weld, activity coefficient
MAP originated from a joint project of the National Physical Laboratory and the University of Cambridge.
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