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"Gateway
A-2 " |
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| Cold
Work |
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| Tool
Steel |
Gateway
A-2 |
is a air hardening alloy tool steel
which provides a good combination |
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of wear resistance, toughness, ease
of heat treatment and minimum distortion.
Special melting |
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and refining 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 uniformity |
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of structure and freedom from
defects. Meets ASTM A-681. |
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| Typical
Chemistry |
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Carbon |
.95/1.05 |
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Chromium |
4.75/5.50 |
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Manganese |
.40/1.00 |
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Vanadium |
.15/.50 |
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Phosphorus |
.030 max |
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Molybdenum |
.90/1.40 |
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Sulfur |
.030 max |
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Silicon |
.10/.50 |
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| Applications |
Gateway A-2 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
1500/1600 F and hold two hours. Cool
slowly (50 F per hour max) |
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to 1400 F, hold six hours and air
cool. Hardness 235 BHN maximum. |
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| Heat
Treating |
Gateway
A-2 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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After preheating to 1500 F for one
half to one hour, heat to 1750/1800 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. Representative |
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hardness levels after tempering are
tabulated below. |
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Air cooled from 1750 degrees F -
Tempered 4 hours |
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Tempering |
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Temperature (F) |
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Hardness (HRC) |
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400 |
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60/62 |
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500 |
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59/61 |
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600 |
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58/60 |
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700 |
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57/59 |
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800 |
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56/58 |
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900 |
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56/58 |
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1000 |
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54/56 |
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1100 |
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48/50 |
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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-2 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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