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.
Calculates the volume fractions of bainitic ferrite, martensite and retained austenite which form in a steel weld on cooling.
Language: | FORTRAN |
Product form: | Source code |
SUBROUTINE MAP_STEEL_BAINCA(CC,TINT,C1,C2,CURR,VOLT,EFF, | |
& | SPEED,AVOLB,VMART,VAUSTR,VMART2,VAUST2,VOLFRA,VOLW,W1,JRICH) |
| |
DOUBLE PRECISION AVOLB,CC(8),C1,C2,CURR,EFF,SPEED,TINT | |
DOUBLE PRECISION VAUSTR,VAUST2,VMART,VMART2,VOLFRA,VOLW | |
DOUBLE PRECISION W1,VOLT | |
INTEGER JRICH |
MAP_STEEL_BAINCA predicts the volume fractions of the microstructures formed in a steel weld on cooling [1]. It calculates the volume fraction of bainitic ferrite, and uses two different methods to obtain the volume fractions of martensite and retained austenite (see references 2 and 3 for further details).
The subroutine is designed for welding problems involving continuous cooling transformations, the cooling curves being determined by the parameters C1 and C2, the welding current, voltage, speed and arc transfer efficiency, and the interpass temperature. All of these are required as inputs to this subroutine. C1 and C2 are heat flow constants which depend on the welding process and are derived from equation 1(b) of reference [4]:
where dT/dt is the cooling rate, Q is the heat input (Jm-1), eta is the arc weld efficiency, and Ti is the interpass temperature.
This subroutine calls MAP_STEEL_BAINTT to calculate a series of C curves for bainite for a range of austenite carbon concentrations. MAP_STEEL_BSMS is used to obtain values for the bainite and martensite start temperatures and to calculate the To and To' curves of the temperature versus carbon plot on the paraequilibrium phase diagram. For each C curve MAP_STEEL_XALPH gives the carbon concentration of the bainitic ferrite, and the volume fraction formed is obtained from the To and To' curves using the lever rule. Scheil's rule [5] is then used to obtain the total volume fraction of bainite formed during cooling. Given the martensite start temperature, the ambient temperature (assumed to be 20 °C) and the remaining volume fraction of austenite, the volume fraction of retained austenite and the volume fraction of martensite are determined by calling subroutines MAP_STEEL_MART (Khan & Bhadeshia method) and MAP_STEEL_MART2 (Koistinen & Marburger method).
The variable JT in the subroutine is the temperature interval at which calculations are made (currently 40 °C). The accuracy can be improved by using a smaller value.
The variable TCAMB in the subroutine is set equal to the ambient temerature, which is assumed to be 20 °C, and is used for the calculation of the amount of retained austenite.
If VOLFRA+VOLW>0.99 no calculations are carried out as there is then no austenite present to transform.
DOUBLE PRECISION CC(8),TINT,C1,C2,CURR,VOLT,EFF,SPEED,VOLFRA DOUBLE PRECISION AVOLB,VMART,VAUSTR,VMART2,VAUST2,VOLW,W1 INTEGER I C W1 = 48570D0 WRITE(*,*) 'Input C Si Mn Ni Mo Cr V (wt%):' READ (*,*) (CC(I), I=1,7) WRITE(*,*) 'Input welding parameters:' WRITE(*,*) 'Interpass T (deg. C), C1, C2, Efficiency:' READ (*,*) TINT,C1,C2,EFF WRITE(*,*) 'Current (A), Voltage (V), Speed (m/s):' READ (*,*) CURR,VOLT,SPEED WRITE(*,*) 'Input initial volume fraction of allotriomorphic', & ' ferrite:' READ (*,*) VOLFRA WRITE(*,*) 'Input initial volume fraction of Widmanstatten ', & 'ferrite:' READ (*,*) VOLW JRICH = 0 IF (VOLFRA.GT.0.0 .OR. VOLW.GT.0.0 ) JRICH = 1 CALL MAP_STEEL_BAINCA(CC,TINT,C1,C2,CURR,VOLT,EFF,SPEED,AVOLB, & VMART,VAUSTR,VMART2,VAUST2,VOLFRA,VOLW,W1,JRICH) WRITE (*,1) AVOLB WRITE (*,2) VMART,VAUSTR WRITE (*,3) VMART2,VAUST2 STOP 1 FORMAT (/'Volume fraction of bainite = ',F8.5/) 2 FORMAT ('Khan and Bhadeshia:'/ & 'Volume fraction of martensite = ',F8.5/ & 'Volume fraction of retained martensite = ',F8.5/) 3 FORMAT ('Koistinen and Marburger:'/ & 'Volume fraction of martensite = ',F8.5/ & 'Volume fraction of retained martensite = ',F8.5/) END
Input C Si Mn Ni Mo Cr V (wt%): 0.05 0.5 1.0 0 0 0 0 Input welding parameters: Interpass T (deg. C), C1, C2, Efficiency: 200 1325 1.6 0.775 Current (A), Voltage (V), Speed (m/s): 180 34 0.004 Input initial volume fraction of allotriomorphic ferrite: 0.39 Input initial volume fraction of Widmanstatten ferrite: 0.25
Volume fraction of bainite = 0.30576 Khan and Bhadeshia: Volume fraction of martensite = 0.03361 Volume fraction of retained martensite = 0.02063 Koistinen and Marburger: Volume fraction of martensite = 0.04772 Volume fraction of retained martensite = 0.0065
Subroutines | Functions | ||||
MAP_STEEL_BAINTT | MAP_STEEL_CULRAT | ||||
MAP_STEEL_BSMS | MAP_STEEL_XALPH | ||||
MAP_STEEL_MART | |||||
MAP_STEEL_MART2 |
Subroutines | Functions | ||||
MAP_STEEL_GMAAX | MAP_STEEL_AFEG | ||||
MAP_STEEL_OMEGA | MAP_STEEL_CG | ||||
MAP_STEEL_TTTT | MAP_STEEL_ENERGY |
Subroutines | Functions | ||||
MAP_UTIL_ANALY | MAP_STEEL_ENERGY | ||||
MAP_STEEL_AXTO |
Subroutines | Functions | ||||
None. | MAP_STEEL_GMART | ||||
MAP_STEEL_GMDASH |
Subroutines | Functions | ||||
None. | MAP_STEEL_FTO1 | ||||
MAP_STEEL_G91 |
bainite, martensite, retained austenite, steel, weld, cooling
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