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EDRO #2 is a
vacuum-degassed Chromium-Molybdenum-alloyed steel which is supplied in the
hardened and tempered condition. EDRO #2 is characterized
by:
- Excellent
machinability
- Good resistance to
indentation
- Uniform hardness in all
dimensions
- Holders/bolsters for
plastic molds and die-casting dies
- Plastics and rubber molds
with low requirements on polishability
- Support plates
- Constructional
parts
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Impact strength
Approx. values. Samples taken from a
round bar 1" (25 mm) diameter. Hardness: 310 HB.
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Testing
temperature
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68°F
(20°C)
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390°F
(200°C)
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750°F
(400°C)
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Joules
Ft. lbs.
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50
37
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55
41
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65
53
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Tensile strength
Approx. values. Samples taken from a
round bar 1" (25 mm) diameter. Hardness: 310 HB.
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Testing
temperature
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68°F
(20°C)
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390°F
(200°C)
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750°F
(400°C)
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Tensile
strength
psi
N/mm2
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146,000
1010
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138,000
950
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115,000
790
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Yield
strength
psi
N/mm2
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116,000
800
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109,000
750
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91,000
630
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Reduct. in
area
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50%
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52%
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54%
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Elongation
in 2"
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18%
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20%
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23%
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EDRO #2 is intended
for use in the hardened and tempered condition, i.e. the delivery
condition.
Flame and induction
hardening
EDRO #2
can be flame or induction hardened to a hardness of 50 RC. Cooling in air is
preferable. Smaller pieces may, however, require forced colling. Hardening
should be immediately followed by tempering.
Nitriding
Gas Nitriding
Nitriting gives a hard
surface which is a very resistant to wear and erosion. A nitrided surface also
increases the corrosion resistance. The surface hardness after nitriding at a
temperature of 980°F, 525°C in ammonia gas will be approx. 650
HV.
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Nitriding
temperature
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Nitriding
time
hours
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Depth of case
approx.
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20
30
60 |
0.012
0.014
0.020 |
0.30
0.35
0.50 |
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Tufftriding (Tenifer
process)
Tufftriding at 570°C,
1025°F will give a surface hardness of approx. 700 HV. After 2 hours
treatment, the hard layer will be approx. 0.0004 in., (0.01 mm).
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Milling
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Carbide tools and high
speed steel tools
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Rough milling
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Finish milling
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Depth of cut (t) in
mm
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min. 0.08
min. 2
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max. 0.08
max. 2
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Feed (s) in/tooth
mm/tooth
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min. 0.08
min. 2
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max. 0.08
max. 2
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ISO machining group
Cutting speed (v) f.p.m.
m/min
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Carbide
tools
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P30-P40
230-330
70-100
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P10-P20
295-380
90-115
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Cutting speed (v)
f.p.m.
m/min
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High
speed steel tools
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50-100
15-30
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65-115
20-35
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Drilling
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Diam-
eter
in./mm
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Depth of Hole
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0.16/4
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0.16/4
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0.16/4
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0.16/4
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rpm/feed (rev./mm/in.)
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0.16/4
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0.32/8
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0.64/16
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1.0/25
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Chip removal is recommended
when depth of hole is > 4 x D. Flush cooling is to be used.
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The following procedure is
recommended when welding EDRO #2
1. Heat part to approx.
400-500°F, 200-260°C
2. Weld part
3. Stress relieve at
750-930°F, 400-500°C
Electrode:
Chromium-Molybdenum alloyed basic electrodes for welding of structural
steels.
Note: Use a well dried
basic electrode. Welding may also be performed with an austenitic stainless
steel electrode. In this case this stipulated increased working temperature may
be modified, but the weld metal has a lower strength (hardness) than the parent
material.
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