ASM 2003 Paper Application of IQ Processes toCarburized Parts
Fine Carb Advantages R2
1. ADVANTAGES OF FINE
CARBURISING PROCESS
Reduction of gas consumption
Reduction of Carburising time (for FC-
35-ACM)
Equalising of carburised depth between
pitch circle diameter and tooth root of a
gear
No gas generator required
2. FC-35
Produces high quality carburisation
Shortens the carburising time and increases the
productivity (estimated over 20% more productivity than
endothermic gas method)
A Gas generator is not required
The cost of atmosphere gas in the Continuous Furnace is
approximately one sixth of the endothermic gas method
and in the Batch Furnace, this figure is one eleventh.
This process is effective in prevention of environmental
contamination in the Continuous Furnace because of
minimal exhaust gas generation (approximately 1/100 of
endothermic gas method and in the Batch Furnace, this
figure is 1/23.
Shortens the seasoning time in a Batch Furnace.
Less than half in the case of Batch Furnace as compared
to an Endothermic method.
3. FC-35-ACM
Adding to the features of FC-35 the
productivity is further increased by
approximately 10% over the FC-35
method.
Inhibits sooting in high carbon
potential carburising
4. FC-30
Obtains the same quality as endothermic gas
method.
The carburising time is same as in the
endothermic gas method
The cost of atmosphere gas is approximately
one ninth of the endothermic gas method
This process is effective in prevention of
environmental contamination in the Continuous
Furnace because of minimal exhaust gas
generation (approximately 1/100 of endothermic
gas method and in the Batch Furnace, this
figure is 1/23.
5. CONSTRUCTION OF A CONTINUOUS GAS CARBURISING
FURNACE
10111213 3459 12678
Degreas
ing
Furnace
Entrance
Chamber
Preheatin
g Zone
Carburisin
g
Diffusion
Zone
Turn
Position
Exit
conveyor
Quench Tank
Hardenin
g 2
Hardenin
g 1
ACM
PROCES
S
6. COMPARISION OF OPERATING CONDITIONS OF FC-35-ACM
AND ENDOGAS
Proces
s
Method
Process
Parameter
Preheatin
g 1
Preheatin
g 2
Carburising Diffusio
n
Turn
positio
n
Hardenin
g 1
Hardening
2
Endo
Gas
Temperat
ure
890 920 940 940 940 1 2
Carbon
Potential
- - 1.15 1.05 - - 0.80
FC-
35-
ACM
Tempera
Ture
930 930 940 940 940 830 850
Carbon
Potential
- - 1.25/
0.95
1.25/
0.95
- - 0.75
Cycle Time
Endogas – 70 min
FC-35-ACM – 45
min
Carburising Specifications
Material : SCM 420
Surface hrdness : Hv (10 kg) 730 over
E.C.D : 1.50 ~ 2.05 mm (at Hv (300g) 513)
Core hardness : Hv (1 kg) 300-500
7. OXYGEN PROBE CARBON POTENTIALATMOSPHERE
CONTROL SYSTEM
Endothermic
gas
Or Air or CO2
Oxygen Probe
FURNACE
Pv
0.90
Sv
0.90
mV-CP
converter
CP
Controller
Control Valve
Gas Line
Signal Line
Enrichmen
t Gas
9. COMPARISION OF FC METHOD WITH ENDOTHERMIC GAS METHOD
CHARACTERST
IC
FC-20 FC-35 FC-35-ACM
SAVING GAS EXCELLENT GOOD GOOD
QUALITY SAME AS ENDO GOOD EXCELLENT
PRODUCITVITY SAME AS ENDO GOOD EXCELLENT
GOOD MEANS BETTER THAN ENDO
EXCEELENT MEANS MUCH BETTER THAN ENDO
10. ATMOSPHERE GAS COST COMPARISION (JAPAN)
0
100
200
300
400
500
600
700
800
FC 35 FC 20 ENDO
Atmosphere Gas Consumption (Continuous Furnace - 30 min cycle time)
Endo LPG Endo heat Enrich heat CO2
11. ATMOSPHERE GAS COST COMPARISION
(JAPAN)
0
50
100
150
200
250
300
FC 35 FC 20 ENDO
Atmosphere Gas Consumption - Batch Type Furnace - 6 hours cycle
time)
x1000Yen/year
Endo LPG Endo heat Enrich heat CO2
13. FC-35ACM AND FC-35
1. FC-35-ACM
930 Deg.c. x 6 hour – 830 Deg.c. x 0 min – 130 Deg.C. Mar quench
2. FC-35
930 Deg.C. x 6 hour – 850 Deg.C. x 0 min – 130 CM.Q
130 Dg.c. Mar Quench
Oxygen Probe : 1160 mV
3. Analysis method
Analysis of the carbon content is made by an emission spectro
analysis