COMET 90 - High Chromium Iron

COMET 90 - High Chromium Iron
SPECIFICITY
The high Chromium iron grade is characterized by a Chromium content in the
range of 16 to 19 % and a carbon
content ranging from 2.7 to 2.9 %.
This grade has a martensitic matrix and
contains about 25 to 30 % Chromium
carbides (M7C3) which lead to its good
wear resistance. By comparision to
indefinite chill iron, the tensile properties are doubled. This led to big
improvements regarding the
appearance of fire cracks. According to
its applications, Cr & Mo content as well
as heat treatment may be adjusted.
X 100
X 500
MECHANICAL PROPERTIES
1MPa = 1 N / mm2 (= 0.1 kgf / mm2)
• Tensile strength Rt
• Young modulus E
• Compressive yield strength Rc 0,25%
• Compressive strength Rc
• Bending strength
• Ductility (compression)
700 / 800
210000 / 220000
1600 / 1800
2000 / 2800
800 / 1000
5 / 10
MPa
MPa
MPa
MPa
MPa
%
C (Carbon)
Si (Silicon)
Mn (Manganese)
Ni (Nickel)
Cr (Chromium)
Mo (Molybdenum)
P (Phosphorus)
S (Sulphur)
12.7 / 12.9
16 / 20
460 / 480
10-6 1/°C
W/m.K
J/Kg.K
PHYSICAL PROPERTIES
• Thermal expansion (25-400°C) α
• Thermal conductivity (25-100°C) λ
• Specific heat (25-100°C)
Cp
HARDNESS
• Shore
• Vickers
• Equotip
ShC
HV
LE
HARDNESS IN DEPTH
85
80
75
70
65
60
55
50
45
40
35
««« very good
Bonding
zone
Hardness (ShC)
Wear resistance
Sticking - roll oxidation
Fire cracks
Slippage
«« good
«««
««
«««
««
25 / 30
6
• Work rolls for front finishing stands
of Hot Strip Mills
• Backup and work rolls for Hot
Skin-pass Mills
CORE MATERIAL COMBINATION
CORE
5 10 15 20 25 30 35 40 45 50
2.7 / 2.9
0.4 / 0.6
0.9 / 1.1
1.2 / 1.4
16.0 / 19.0
1.2 / 2.0
< 0.05
< 0.04
« weak
• Pearlitic nodular graphite iron
• Lamellar graphite iron
SHELL
Carbide %
Cr/C ratio
[%-wt]
APPLICATIONS
CHARACTERISTICS
65 / 90
500 / 800
715 / 850
CHEMICAL ANALYSIS
Depth
(mm)
MARICHAL KETIN
S.A. DES FONDERIES
J. MARICHAL KETIN & CIE
Rue Ernest Solvay 372
B-4000 Liège (Sclessin)
Belgium
Tel.: + 32 / 4 / 234 72 06
Fax: + 32 / 4 / 234 72 51
E-Mail: [email protected]
Internet: www.mkb.be