Hot die steel H21!
Hot die steel H21, also known as 1.2581, is a type of steel alloy that is widely used in the production of hot work dies, such as die-casting dies, forging dies, and extrusion dies.
Here are some key characteristics of hot die steel H21:
1. High hardness: H21 has a high hardness rating, typically in the range of 48-52 HRC, which makes it highly resistant to wear and tear.
2. High temperature resistance: H21 has a high temperature resistance, up to 600°C (1112°F), which makes it suitable for use in high-temperature applications.
3. Good toughness: H21 has good toughness, which means it can withstand impacts and stresses without breaking or deforming.
4. Resistance to thermal shock: H21 has a high resistance to thermal shock, which means it can withstand sudden changes in temperature without cracking or breaking.
5. Good machinability: H21 is relatively easy to machine, which makes it a popular choice for die makers.
Some common applications of hot die steel H21 include:
1. Die-casting dies: H21 is widely used in the production of die-casting dies, particularly for high-pressure die-casting applications.
2. Forging dies: H21 is used in the production of forging dies, where its high hardness and resistance to wear are beneficial.
3. Extrusion dies: H21 is used in the production of extrusion dies, where its high temperature resistance and resistance to wear are important.
4. Hot stamping dies: H21 is used in the production of hot stamping dies, where its high hardness and resistance to wear are beneficial.
Compared to H13, H21 has a higher hardness and temperature resistance, making it suitable for more demanding applications. However, it also has a higher cost and may be more difficult to machine.
Some of the benefits of using hot die steel H21 include:
1. Long tool life: H21 has a long tool life, which means that dies made from this material can be used for a large number of production cycles.
2. High precision: H21 can be machined to high precision, which makes it suitable for use in dies that require a high level of accuracy.
3. Good surface finish: H21 can be polished to a high finish, which is important for dies that require a smooth surface finish.
4. Resistance to heat checking: H21 has a high resistance to heat checking, which means it can withstand the high temperatures and stresses associated with hot work die applications.
| W.Nr. | DIN | AISI/SAE | JIS |
|---|---|---|---|
| 1.2581 | X40CrMoV5-1 | H-13 | SKD61 |
| C | Si | Mn | P (Max) | S (Max) | Cr |
|---|---|---|---|---|---|
| 0.25-0.35 | 0.10-0.40 | 0.15-0.45 | 0.035 | 0.035 | 2.50-3.20 |
| Way | Temperature (°C) | Procedure |
|---|---|---|
| Forging | 900-1150 | Cool bigger and difficult-shape tools in air or in thermal bath at the temperature of 500 – 550 °C |
| Soft annealing | 750-800 | Warm few hours (according to the size of object), mostly four hours are enough and cool slowly in the furnace |
| Annealing to lower tension | 600-650 | Warm 1 to 2 hours and cool slowly in the furnace |
| Hardening | 1100-1150 | Cool in oil to the temperature of about 100 °C |
| Hardening | 1120-1170 | Cool bigger and difficult-shape tools in air or in thermal bath at the temperature of 500 – 550 °C |
| Tempering | 550-650 | Cool in air, the degree of tempering is set by hardness and toughness of instrument according to the tempering chart |
| Grade | Chemical composition (wt%) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Standard | Equivalent | C | Si | Mn | Cr | V | P | S | W |
| GB | 3Cr2W8V | 0.30-0.40 | <0.40 | <0.40 | 2.20-2.70 | 0.20-0.50 | <0.030 | <0.030 | 7.50-9.00 |
| ASTM | H21 | 0.26-0.36 | 0.15-0.50 | 0.15-0.40 | 3.00-3.75 | 0.30-0.60 | <0.030 | <0.030 | 8.50-10.00 |
| DIN | 1.2581 | 0.25-0.35 | 0.15-0.40 | 0.15-0.45 | 2.50-2.80 | 0.30-0.50 | <0.030 | <0.020 | 8.50-9.50 |
| JIS | SKD5 | 0.25-0.35 | 0.10-0.40 | 0.15-0.45 | 2.50-3.20 | 0.30-0.50 | <0.030 | <0.020 | 8.50-9.50 |
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