1.2550 AISI S1 is an alloy tool steel with high strength and excellent impact resistance. In its hardened state, 1.2550 60WCrV7 is a heat-resistant tool steel that combines high hardness with good strength and impact resistance.1.2550 is one of the tool steels with excellent impact resistance and has good quenching properties. Impact resistant tungsten alloy tool steel for cold working.
General purpose: tungsten tool steel, impact resistance. It is a versatile steel with excellent properties for cold and hot impact tools. Being low carbon contributes to the strength. Has enough forming carbide to provide sufficient wear resistance and hardening depth for most impact tools. For additional wear resistance, the surface of the tool is carburized during the shoot hardening process. It still retains its impact resistance. The silicon content improves the hot workability of high temperature impact tools.
Applications: Sheet metal cutting tools (dies and punching dies), woodworking tools, punching dies for sheet metal cutting up to 12mm thick, cutting and splitting dies, cold punching dies, punching dies, punching knives, pneumatic chisels, painting tools, cold cutting knives, ejectors.
Forging: 1.2550 steel tool elements should be heated slowly and evenly to 1000°C. Forging: Forging in the range of 1000/800°C and reheating if necessary. Cool slowly (preferably in the furnace) so that no stress is generated. ANNEALING: Heat tool 1.2550 evenly to 770°C, level and then cool the oven.
Relieve the tension. If the machining is heavy, or if tool 1.2550 has an unbalanced section, heat it to 700°C to remove the stress before quenching, align it, and then slowly cool it down.
Hardening: Preheat the tool steel 1.2550 to 650°C and soak it thoroughly. Continue heating to a final curing temperature of 900/950°C. Allow enough time for the components to warm up. Cured in oil.
Maltempering: Maltempering is an alternative curing method to 1.2550 that can be used when suitable salt bath equipment is available.
Purchase: This metal can be bought for a relatively low price. Get your AISI 420 here.
Advantages
- Maximum shock resistance for cold or hot work applications
- Good wear resistance
- Good red-hardness value
Typical Analysis
CARBON ……………0.50 CHROMIUM ………..1.15
SILICON ……………0.75 TUNGSTEN ………..2.50
VANADIUM …………0.20
FORGING ………………………………..2000°F to 2100°F, stop at 1600°F
NORMALIZING …………………………Do not normalize
ANNEALING ……………………………1475°F, cool slowly. Brinell 212 max
PREHEATING ……………………………1200°F – prior to hardening
HARDENING …………………………….1750 °F, oil quench to 150°F
TEMPERING ………………………………300° to 500° F cold work, hardness Rockwell c-57-64, 1000° F, for hardness Rockwell C-47-42.Machinability
In the thoroughly annealed condition, has a machinability rating of 75, as compared with a rating of 100 for a one percent carbon tool steel.Tempering Results
Specimens 1 in. diameter by 6 in. long were quenched in oil from 1750° F and tempered at 100°F intervals from 300°F, to 1200°F for one hour.
| Tempering Temperatures °F | Hardness Rockwell C |
| None | 57 |
| 300 | 55 |
| 400 | 54 |
| 500 | 53 |
| 600 | 51 |
| 700 | 51 |
| 800 | 50 |
| 900 | 49 |
| 1000 | 47 |
| 1100 | 45 |
| 1200 | 42 |
Results may be used as a guide in tempering tools to desired hardness. However, since 1 in. diameter specimens were used in this test, tools of heavy section or mass may be several points lower in Rockwell hardness for a given treatment.
| Tempering °C | 150 | 200 | 250 | 350 | 400 |
| HRc | 62/61 | 61/60 | 60/59 | 58/57 | 55/54 |
| Chemical Composition | ||||
| C. | Si. | Mn. | Cr. | V. |
| 0.50% | 0.80% | 1.50% | 2.50% | 0.20% |
In conclusion, its high impact absorbance and cheap price for such a high strength makes it the perfect alloy for manufacturing different objects, such as knives.
