Outline of Komatsu

1
Name Chikara Nakao Birth Kyoto, Japan
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Outline of Komatsu
Construction Mining Equipment
Businesses
Electronics
Industrial Machinery
Others
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Group Companies
Osaka plant
Head office Tokyo
15 companies
Europe, Middle East and Africa
142 consolidated companies
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Payload capacity 290 tons Flywheel
horsepower 2,500 HP(1,865 kW)
930E
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Board of directors
Production Division
Head office administration
Research Division
Developing Division
Manufacturing Engineering Development Center
Awazu Plant
Osaka Plant
Administration Dept.
Oyama Plant
Materials Development Group
Process Development Group
System Development Group
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Heat treatment for Hydraulic Excavator
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Dispersion of Aluminum Nitride by carbonitriding
process in Al containing Steels
1.0
Al mass
0
1
2
N mass ppm
Solubility of AlN in Austenite
8
Gas Carburizing


Carbonitriding


20 min
4.0H
40 min
CP1.3
CP0.8
(CH3OHC3H8 NH3)
(CH3OHC3H8)
3
1
NH3 N2 H2
2

2
3
NH3 N H2
2
CP Carbon potential
9
Microstructure (5 nital)
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Nitrogen profile (EPMA)
N
Distance from surface
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Effects of Al content on nitride precipitates
layer
Nitride precipitates layer x
B Medium Al steel
A Low Al steel
C High Al steel
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Wager's internal oxidation equation
(mol/m3)
N
C
S
d
C
N
N
_at_
d x
ÉÃ
x
x
0
(m)
At xx, consumption of Al is equal to nitrogen
supply .
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Low CNS
Low Al content Medium Al content High Al content
Experimental x
High CNS
Low Al content Medium Al content High Al content
0
0
Calculated x

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Numerical analysis of N and Al distribution
Al
Concentration
N
Distance from surface
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Prediction of hardness, stress, and stain in
various conditions
Input Shape, chemical composition of steel,
Jominy curve, CCT data .... Calculation (FEM)
Carbon diffusion, thermal calculation,
elasto-plastic analysis Output Carbon
distribution, hardness, microstructure, stress,
distortion....
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Calculation of carburizing and quenching
tensional
Austenite
Martensite
compressive
Bainite
Hardness profiles
Carbon distribution
Residual stress distribution
Microstructure ( 20 sec after quenching)
930C
Steel SCM420H (Fe-0.21C-0.25Si-0.73Mn-0.1Ni-1.0C
r-0.25Mo)
850C
5h
1h
1h
Heat-treatment Carburizing