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"Gateway
A-6 " |
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| Cold
Work |
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| Tool
Steel |
Gateway
A-6 |
is a air hardening alloy tool steel
which provides a good combination |
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of wear resistance, toughness, and
strength. This grade is noted for ease of heat treatment and |
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minimum distortion, due to it's
ability to be air hardened from a low hardening temperature. |
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Special melting practices are
utilized to produce a uniform product with high cleanliness and |
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minimum
segregation. The material is tested
to rigorous tool steel standards to
ensure |
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uniformity of structure and freedom
from defects. Meets ASTM A-681. |
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| Typical
Chemistry |
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Carbon |
.65/.75 |
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Manganese |
1.80/2.50 |
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Phosphorus |
.030 max. |
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Sulfur |
.030 max. |
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Silicon |
.10/.70 |
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Chromium |
.90/1.40 |
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Molybdenum |
.90/1.40 |
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| Applications |
Gateway A-6 is suitable for use in
cold work tooling applications requiring a combination |
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of wear resistance and toughness
such as thread roll dies, punches, blanking dies, shears and |
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forming dies. The grade is also used for plastic molds
requiring high wear resistance. |
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| Annealing |
Heat slowly and uniformly to
1350/1375 F and hold two hours. Cool
slowly (20 F per hour max) |
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to 950 F or below, then air cool to
room temperature. Hardness 250 BHN
maximum. |
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| Heat
Treating |
Gateway
A-6 is subject to decarburization during heat treatment, so a protective |
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atmosphere furnace or vacuum furnace
should be used. |
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Preheat to 1250 F for one half to
one hour; then heat to 1525/1600 F and soak |
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one half hour when material is up to
temperature. Air cool to hand warm
(approximately 150 F) |
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and temper immediately. |
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| Tempering |
Double temper one hour per inch of
section thickness to desired hardness, two hours minimum |
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per temper. Representative hardness levels after
tempering are tabulated below. |
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Air cooled from 1550 degrees F -
Tempered 4 hours |
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Tempering |
(Section Size - 4" x
4") |
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Temperature (F) |
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Hardness (HRC) |
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300 |
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60/61 |
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400 |
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58/59 |
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500 |
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56/57 |
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600 |
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55/56 |
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700 |
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54/55 |
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800 |
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52/53 |
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900 |
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50/51 |
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1000 |
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48/49 |
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Note: |
Variations in section size, heating
rate, soak time, quench rate and tempering will |
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cause
deviations from the above values.
Gateway Metals should be consulted for specific |
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applications. |
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| EDM |
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Electro-discharge machining is
widely used in the production of plastic molds and other tooling. |
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However, this operation produces
recast, rehardened, and retempered layers on the die surface. |
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It
is recommended that Gateway A-6 be stress relieved at 50 F below the final
tool |
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tempering
temperature after electro-discharge machining to temper the rehardened layer |
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produced by EDM. |
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