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| High
Strength Equivalent to Stainless Steel |
|
|
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| The strength (tensile strength and yield strength) of
ECO BRASS is about 1.4 times as great as that of C3604
and C3771, equivalent to that of C6782 with the highest
strength among wrought copper alloys and the same as
stainless steel SUS304/SUS303. |
|
Tensile Strength
|
Yield Strength
|
 |
 |
|
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| Excellent
De-Zincification Corrosion Resistance |
|
|
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| ECO BRASS has excellent dezincification corrosion
resistance and is the same as C83600 (BC6). Forgings and
castings of ECO BRASS have excellent dezincification
corrosion resistance without heat treatment after
forging and casting. |
|
Corrosion depth after
ISO6509
dezincification corrosion test
|
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 |
 |
|
EcoBrass
|
C3604
|
Maximum corrosion depth of C3604 and C3771 is almost
0.04" (1.0mm), but the corrosion depth of ECO BRASS
is almost zero, the same as *UR or BC6.
*UR is Mitsubishi Shindoh's "Ultra Restraint"
brass series.
|
|
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| Excellent
Stress Corrosion Cracking Resistance |
|
|
|
| Stress corrosion cracking is a common problem with
traditional brass materials. The photo shows an
example of stress corrosion in alloy C3604.
ECO BRASS contains 21% zinc, much lower than
traditional brass materials, and an addition of 3%
silicon, which suppresses stress corrosion cracking.
In each accelerating test, JIS A, CES A and
Mattsson's, ECO BRASS sensitivity to stress corrosion
cracking was less than 1/30 of that of C3604 or C3771.
|
|
Stress Corrosion in
C3604
|
|
Enlargement
|
|
|
 |
 |
Test pieces are made by cutting an internal thread on
hexagonal bars. The test is performed with 1500 kgf cm
torque loaded.
JIS A method: Soaking in an atmosphere of NH4OH
aqueous solution (concentration: not less than 11.8%)
for 2 hours at room temperature and identify cracks by
visual observation.
|
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| Excellent
Warm Brittleness Cracking Resistance |
|
|
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| Traditional free-cutting brass contains lead, which
has a low melting point of 572oF (300°C). Because of
the lead content, the impact value rapidly decreases.
When the material is worked, heat is generated and
cracking occurs. This phenomenon is called warm
brittleness cracking. ECO BRASS contains no lead and
does not suffer from warm brittleness cracking. |
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