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Ductile Iron Society T&O Meeting
Milwaukee, June 18-20 2008
UNDERSTANDING THEUNDERSTANDING THEUNDERSTANDING THEUNDERSTANDING THEUNDERSTANDING THE UNDERSTANDING THE FORMATION OF DROSS IN FORMATION OF DROSS IN DUCTILE IRON CASTINGSDUCTILE IRON CASTINGS
UNDERSTANDING THE UNDERSTANDING THE FORMATION OF DROSS IN FORMATION OF DROSS IN DUCTILE IRON CASTINGSDUCTILE IRON CASTINGSDUCTILE IRON CASTINGSDUCTILE IRON CASTINGSDUCTILE IRON CASTINGSDUCTILE IRON CASTINGS
Martin Gagné, Marie-Pierre Paquin, Pierre-Marie Cabanne
RIO TINTO Iron & Titanium – SorelmetalSorel-Tracy, CanadaFrankfurt, Germany
Dross slag & sand inclusions are the three major non metallic
DEFINITIONS:DEFINITIONS:DEFINITIONS:DEFINITIONS:Dross, slag & sand inclusions are the three major non-metallic
inclusions found in DI;
Drosses are endogenous while slag and sand inclusions areDrosses are endogenous while slag and sand inclusions are exogenous;
Drosses have a filamentary aspect while slag inclusions exhibit a osses a e a a e ta y aspect e s ag c us o s e b t ablocky appearance;
Magnesium silicate filaments (drosses) are forming within the iron during pouring (in the stream, in the pouring basin, in the gating system or during the first filling of the mold cavity),whereas slag is mainly originating from the magnesium treatment and theslag is mainly originating from the magnesium treatment and the residues from the furnace and the ladle.
EXAMPLES:EXAMPLES:EXAMPLES:EXAMPLES:
Slag and Sand Defects:
« C » area at high magnification
1= 44%SiO2, 52%MgO;1 44%SiO2, 52%MgO;
2= 53%SiO2 , 18%CaO, 16%MgO;
3 = 54%SiO2, 18%Al2O3, 10% CaO, 15%FeO
Slag & Sand Inclusions:
A= 54%SiO 17%MgO 18%CaO;
1
A= 54%SiO2, 17%MgO,18%CaO;
B= SiO2 100% sand;
C=
2
C 3
EXAMPLES:EXAMPLES:EXAMPLES:EXAMPLES:
Dross Defects:
Analysis no. 1 2 3 4 5 6
MgO 25% 14 16 48 40 24
SiO2 56% 55 62 44 36 33
Al O 7% 5 8 5 6 1Al2O3 7% 5 8 5 6 1
CaO 0.5 - - - - -
MnO 5 23 11 - 3 8
FeO 4 3 2 2 16 31
EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:
Ductility
20
22
16
18
gatio
n (%
)
10
12
14
Elon
8
10
7 9 11 13 15 17 19 21 23
Perlite Content (%)Perlite Content (%)
EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:
Low Ductility: Dross on Fracture Surface
Dross
EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:
Impact Energy: Dross on Fracture Surface
No Dross: 114 lb-ft With Dross: 52 lb-ftADI: un-notched Charpy specimens
EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:EFFECT on MECHANICAL PROPERTIES:
Defect Rel. Fatigue Endurance
Fatigue Strength:
None 1.00Dross 0,54
Micro shrinkage. 0,73
Macro shrinkage 0,50
Chunk graph. 0,75
Anomalies 0,83
(Frauenhofer Institute / Refstie & Skaland – Vesta Group)
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:
Ellingham diagram:
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:
Binary Phase Slag (liq) + MgO
Sl (li 1) +
Slag (liq)Binary Phase
Diagram
MgO – SiO
Slag (liq) + SiO2
Slag (liq1) + Slag (liq2)
MgO – SiO2
SiO2 + MgSiO2
MgSiO2+
Mg2SiO4
MgO + Mg2SiO4
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:
Thermodynamic simulations were carried out to determine the conditions for dross formationdetermine the conditions for dross formation
General Parameters:%S 0 010 & 0 020• %S : 0,010 & 0,020;
•%Si: 2,0 & 2,5; •%Mg: 0 04 0 06%;•%Mg: 0,04 – 0,06%; •Temp.: 1300 to 1500C; •Oxygen: 10 to 1000 ppm.yg pp
Simulation by FactSage software (developed at École Polytechnique de Montréal); this software assumesPolytechnique de Montréal); this software assumes equilibrium is reached.
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:
Thermodynamic simulations were carried out to determine under which conditions dross would form
Parameters:• %S : 0,010 & 0,020; •%Si: 2,0 & 2,5; •%Mg: 0,04 – 0,06%; •Temp.: 1300 to 1500C;
•Oxygen: 10 to 1000 ppm to simulate turbulence!
Magnesium compounds formationFORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Magnesium compounds formation
%S: 0,010
%Si: 2 0%Si: 2,0
%Mg: 0.04 & 0.05
%O: 10, 100 & 200 ppm
Temperature: 1300-1500 C
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Magnesium compounds formation
Magnesium Oxide with % Mg = 0 04 – 0 05
Magnesium compounds formation
0 04 % 0 05 %
Magnesium Oxide with % Mg = 0.04 – 0.05
0.05
0.06
on
0.05
0.06
on
0.04 % 0.05 %
0.03
0.04
crea
ted
in 1
00g
of ir
o0 02
0.03
0.04
cre
ated
in 1
00g
of ir
0.00
0.01
0.02
1250 1300 1350 1400 1450 1500 1550
g of
MgO
0.00
0.01
0.02
1250 1300 1350 1400 1450 1500 1550
g of
MgO
1250 1300 1350 1400 1450 1500 1550
temperature (C)
0.05% Mg et 10ppm O 0.05%Mg et 100ppm O 0.05%Mg et 200ppm O
50 300 350 00 50 500 550
température (C)
0.04%Mg et 10ppm O 0.04%Mg et 100ppm O 0.04%Mg et 200ppm O
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Magnesium compounds formationMagnesium compounds formation
Magnesium Silicite (MgxSiy) with % Mg = 0.04 – 0.05, 2,0% Si
0 04 % 0 05 %
Magnesium Silicite (MgxSiy) with % Mg 0.04 0.05, 2,0% Si
0.07
0.08
n
0.07
0.08
n
0.04 % 0.05 %
0 03
0.04
0.05
0.06
crea
ted
in 1
00g
of ir
on
0 03
0.04
0.05
0.06
crea
ted
in 1
00g
of ir
on
0.00
0.01
0.02
0.03
1250 1300 1350 1400 1450 1500 1550
g of
dro
ss c
0.00
0.01
0.02
0.03
1250 1300 1350 1400 1450 1500 1550
g of
dro
ss c
1250 1300 1350 1400 1450 1500 1550
temperature (C)
0.04%Mg et 10ppm O 0.04%Mg et 100ppm O 0.04%Mg et 200ppm O
1250 1300 1350 1400 1450 1500 1550
temperature (C)
0.05% Mg et 10ppm O 0.05%Mg et 100ppm O 0.05%Mg et 200ppm O
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:
M i d 1° t f d i l tiMagnesium compounds: 1° step of dross simulation
Magnesium Sulphide with % Mg = 0.04 – 0.05, 0,010% S
0 04 % 0 05 %
Magnesium Sulphide with % Mg 0.04 0.05, 0,010% S
0.02
0.02
0.02
f iro
n (g
)
0 01
0.02
0.02
0.02
de 1
00g
de
0.04 % 0.05 %
0.02
0.02
0.02
0.02
S cr
eate
d in
100
g of
0 01
0.01
0.01
0.01
0.01
MgS
form
é à
part
ir d
mét
al (g
)
0.02
0.02
0.02
1250 1300 1350 1400 1450 1500 1550
g of
MgS
0.00
0.00
0.00
0.01
1250 1300 1350 1400 1450 1500 1550
mas
se d
e M
temperature (°C)
0.05% Mg et 10ppm O 0.05%Mg et 100ppm O 0.05%Mg et 200ppm O
température (C)
0.04%Mg et 10ppm O 0.04%Mg et 100ppm O 0.04%Mg et 200ppm O
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:
M i d 1° t f d i l ti
“R id l F ” M i ith % M 0 04 0 05
Magnesium compounds: 1° step of dross simulation
0 04 % of Mg 0 05 % of Mg
“Residual = Free” Magnesium with % Mg = 0.04 – 0.05
0.035
0.040
0.030
0.035
0.04 % of Mg 0.05 % of Mg
0.015
0.020
0.025
0.030
% re
sidu
al M
g
0.015
0.020
0.025
% re
sidu
al M
g
0.000
0.005
0.010
1250 1300 1350 1400 1450 1500 15500.000
0.005
0.010
1250 1300 1350 1400 1450 1500 1550temperature (C)
0.05% Mg et 10ppm O 0.05%Mg et 100ppm O 0.05%Mg et 200ppm O
1250 1300 1350 1400 1450 1500 1550
temperature (C)
0.04%Mg et 10ppm O 0.04%Mg et 100ppm O 0.04%Mg et 200ppm O
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of TemperatureEffect of Temperature
% S: 0,001
% Si: 2 0% Si: 2,0
% Mg: 0,04
O 100 300 500 700 &1000Oxygen: 100, 300, 500, 700 &1000 ppm
Temperature: 1300-1500 C
Effect of TemperatureFORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:
Dross formation vs Temperature for 0.04% Mg, 2% Si & 100ppm O2
Effect of Temperature
2.50E-01
pp 2
1.50E-01
2.00E-01
s
1.00E-01
g de
dro
ss
MgOSiO2
0.00E+00
5.00E-02
g
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Temperature
Dross formation vs Temperature for 0.04% Mg, 2% Si & 300ppm O2
Effect of Temperature
2.50E-01
pp 2
1.50E-01
2.00E-01
ss
Mg2SiO4
1.00E-01
g de
dro
s
g2 4
0 00E+00
5.00E-02
MgO0.00E+00
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Temperature:
Dross formation vs Temperature for 0.04% Mg, 2% Si & 500ppm O2
Effect of Temperature:
2.50E-01
pp 2
1.50E-01
2.00E-01
ss
1.00E-01
g de
dro
s
Mg2SiO4MgO
0.00E+00
5.00E-02
g2 4MgO
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500T(C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Temperature
Dross formation vs Temperature for 0.04% Mg, 2% Si & 700ppm O2
Effect of Temperature
2.50E-01
pp 2
1.50E-01
2.00E-01
1.00E-01
gram
me
Mg2SiO4M SiO
0 00E+00
5.00E-02
Mg2SiO4MgSiO3
0.00E+001300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500
T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Temperature
Dross formation vs Temperature for 0.04% Mg, 2% Si & 1000ppm O2
Effect of Temperature
2 00E 01
2.50E-01
pp 2
1.50E-01
2.00E-01
me MgSiO3
1.00E-01
gram
m
Mg2SiO4
g 3
0.00E+00
5.00E-02
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500
g2 4
SiO21300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500
T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Temperature: SummaryEffect of Temperature: Summary
2.50E-01
Dross formation vs Temperature for 0.04% Mg, 2% Si & 300ppm O2
2.50E-01
Dross formation vs Temperature for 0.04% Mg, 2% Si & 100ppm O2
SummarySummary5.00E-02
1.00E-01
1.50E-01
2.00E-01
g de
dro
ss
Mg2SiO4
5.00E-02
1.00E-01
1.50E-01
2.00E-01
g de
dro
ss
MgOSiO2
Dross formation vs Temperature for 0.04% Mg, 2% Si & 1000ppm O2
Dross formation vs Temperature for 0.04% Mg, 2% Si & 700ppm O2
Dross formation vs Temperature for 0.04% Mg, 2% Si & 500ppm O2
0.00E+001300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 150
T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
MgO0.00E+00
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
1.00E-01
1.50E-01
2.00E-01
2.50E-01
gram
me MgSiO3
1.00E-01
1.50E-01
2.00E-01
2.50E-01
gram
me
1.00E-01
1.50E-01
2.00E-01
2.50E-01
g de
dro
ss
pp 2
0.00E+00
5.00E-02
1.00E 01
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 150T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
Mg2SiO4
SiO20.00E+00
5.00E-02
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500T (C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
Mg2SiO4MgSiO3
0.00E+00
5.00E-02
1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500T(C)
g-MgO(s) g-SiO2(s4) g-MgSiO3(s3) g-Mg2SiO4(s) g-MgS(s)
Mg2SiO4MgO
At high Temperature, dross level is similar
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Oxygen Content (turbulence)Effect of Oxygen Content (turbulence)
% Sulphur: 0.010 0.020
%Magnesium: 0.040 0.060
% Silicon: 2.00 2.50
°C Temperature: 1300 and 1500
ppm Oxygen: from 10 to 1000
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Oxygen Content (turbulence)Effect of Oxygen Content (turbulence)
2.50E-01
2.00E-01
0.01%S, 0.04% Mg, 2% Si & 1300°C
1.50E-01
ross
1.00E-01g of
D
Mg2SiO3
5.00E-02Mg2SiO4
MgOSiO2
0.00E+000.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
MGO SiO2 MgSiO3 Mg2SiO4 MgS
MgO
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Oxygen Content (turbulence)Effect of Oxygen Content (turbulence)
2.50E-01
2.00E-01
0.01%S, 0.04% Mg, 2% Si & 1500°C
1.50E-01
dros
s
1.00E-01g of
d
5.00E-02
MgO
Mg2SiO4
0.00E+000.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
MGO SiO2 MgSiO3 Mg2SiO4 MgS
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Oxygen Content (turbulence)Effect of Oxygen Content (turbulence)
2 50E 01
2.00E-01
2.50E-01
0.02%S, 0.06% Mg, 2.5% Si & 1300°C
1.50E-01
ross
1.00E-01g of
d
Mg2SiO4
0 00E 00
5.00E-02 MgOMg2SiO3
0.00E+000.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
MGO SiO2 MgSiO3 Mg2SiO4 MgS
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Oxygen Content (turbulence)Effect of Oxygen Content (turbulence)
2.50E-01
2.00E-01
0.02%S, 0.06% Mg, 2.5% Si & 1500°C
1.50E-01
Dro
ss
1.00E-01g of
D
Mg2SiO4
5.00E-02 MgO
0.00E+000.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
MGO SiO2 MgSiO3 Mg2SiO4 MgS
FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:FORMATION, EXPLANATION & SIMULATION:Effect of Oxygen Content: Summary
2.00E-01
2.50E-01
0.02%S, 0.06% Mg, 2 5% Si & 1300°C
2.00E-01
2.50E-01
0.01%S, 0.04% Mg,
Effect of Oxygen Content: Summary
1.00E-01
1.50E-01
g of
dro
ss
Mg2SiO4
2.5% Si & 1300°C
1.00E-01
1.50E-01
g of
Dro
ss
2% Si & 1300°C
Mg2SiO3
More Dross at low O2
0.00E+00
5.00E-02
0.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
MgOMg2SiO3
0.00E+00
5.00E-02
0.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
Mg2SiO4Mg2SiO3
MgOSiO2
Less Dross at
2.00E-01
2.50E-01
0.02%S, 0.06% Mg, 2 5% Si & 1500°C
2.00E-01
2.50E-01
0.01%S, 0.04% Mg, 2% Si & 1500°C
MGO SiO2 MgSiO3 Mg2SiO4 MgSMGO SiO2 MgSiO3 Mg2SiO4 MgSLess Dross at
high Temp
More Dross with
1.00E-01
1.50E-01g
of D
ross
Mg2SiO4
2.5% Si & 1500 C
1.00E-01
1.50E-01
g of
dro
ss
high S, Mg, Si
0.00E+00
5.00E-02
0.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
MGO SiO2 MgSiO3 Mg2SiO4 MgS
MgO
0.00E+00
5.00E-02
0.001 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
%O
MGO SiO2 MgSiO3 Mg2SiO4 MgS
MgO
Mg2SiO4
CONCLUSIONS:CONCLUSIONS:CONCLUSIONS:CONCLUSIONS:
Formation of dross is mainly controlled by oxygen content; the l l f i d t th t t l flevel of oxygen required suggests that an external source of oxygen is needed: turbulence!
Dross is mainly a “mixture” of magnesium silicates;Dross is mainly a “mixture” of magnesium silicates;
Dross formation is favored by low pouring temperature, turbulence, high %Mg and high %Si;high %Mg and high %Si;
If all other parameters are kept under control, the effect of pouring temperature is minimized;temperature is minimized;
Sulphur, at low level, does not interact with dross formation.
Composition of dross changes with temperatureComposition of dross changes with temperature.
Thanks!Thanks!Thanks!Thanks!Thanks!Thanks!
Gracias!Gracias!
Thanks!Thanks!
Gracias!Gracias!Gracias!Gracias!
Merci!Merci!
Gracias!Gracias!
Merci!Merci!Merci!Merci!Merci!Merci!
Martin Gagné, Marie-Pierre Paquin, Pierre-Marie Cabanne
RIO TINTO Iron & Titanium – SorelmetalSorel-Tracy, CanadaFrankfurt, Germany