The requirements for selecting plastic mold materials and hardness are generally determined based on the total modulus (output, time length), precision, and applicable plastic raw materials of the products produced.
The specific mold materials and hardness reference materials are as follows:
1. Germany 2311 (P20)
Factory status: HB270-320
Steel properties: High-quality plastic mold steel
Usage: Long-term production of high-quality plastic molds.
2. German 2738 (738/718)
Factory status: pre-hardened to 31-35HRC (290-330HB) 738H pre-hardened to 330-370HB
Steel characteristics: Steel is added with nickel, which has uniform hardness and good cutting ability. It is more suitable for large molds, such as electrical products, and can be processed by EDM. Usage: Used for manufacturing high-grade plastic injection molds, etc.
738 is suitable for large molds. With an additional 1% nickel content, its hardenability and hardness are greatly improved compared to 2311. Therefore, the steel type is pre-hardened, so there is no need to perform heat treatment and other processes after processing.
3. Germany 2344 (8407 H13 W302)
Factory status: HB180-210
Steel characteristics: clean and uniform steel, good structure, with 3000 tons It is forged by a press and has high impact strength. After ultrasonic inspection, the black skin on the surface is removed by processing. The material utilization rate is high, and the processing cost can be reduced. It has the best red hardness and good edge properties.
Uses: Die-casting molds for zinc, aluminum, tin and other non-ferrous alloys and copper alloys, or nozzles, extrusion shafts, etc., can be used as hot forging or stamping dies, and can be made into high-grade products after quenching Permanent production of plastic molds.
4. Germany 2316 (commercial name: S136H S136)
Factory status: HB265-310
Steel characteristics: best polishability; good permeability , good corrosion resistance. After quenching and mirror polishing, the corrosion resistance of this steel is more reliable. Pre-hardened, excellent corrosion resistance, suitable for mirror and acidic plastic molds.
The use hardness of 2316A is 45-47HRC. At this time, the corrosion resistance effect is the best.
5. German 2510 Commercial name: German oil steel
Factory hardness: soft annealed to about 230HB
Features: This steel is manganese, chromium, tungsten Alloy steel is a high-quality non-deformable cold work tool steel with excellent machinability. When quenched, it is extremely dimensionally stable and the surface has extremely high hardness after quenching.
It has extremely high edge properties, so it has excellent wear resistance, and is easy to forge and quench. It is suitable for widespread use in cutting, cold stamping and forming tools, such as notch dies, cold stamping dies, Various gauges,
gong cutters, reamers, mold bushings and small plastic molds.
6. German 2083 acid-proof mirror mold steel
Factory hardness: hardened and tempered to HB265-310
Features: Can be hardened to 52HRC anti- Acid mirror mold steel. It has good polishing performance and is suitable for electric corrosion. Usage: Suitable for acidic plastics and molds that require good polishing. 2083H can be pre-hardened to 280-310HB with good acid resistance and polishing properties. 7. Japan’s high-quality brand steel S50C S55C No. 55 steel
Steel characteristics: This steel is suitable for general plastic molds. Because of its high carbohydrate content, it is more durable than ordinary steel and is more affordable. More commonly used.
8. Sweden 718H
Factory status: pre-hardened to 35-39HRC
Steel characteristics: Steel is added with nickel, the hardness is uniform, and the cutting is good, which is more suitable Large molds such as electrical products can be processed by EDM. Usage: Used for manufacturing high-grade plastic injection molds.
9. Swedish S136H pre-hardened transparent corrosion-resistant mirror mold steel.
Factory status: quenched and tempered HRC31-35
Features: Best polishability; good permeability, good corrosion resistance, this steel mold has been quenched and mirror-polished Its corrosion resistance is more reliable after light treatment.
S136, S136H heat treatment analysis S136: annealed to 215HB
S136H: pre-hardened to 290-330HB
High purity, high mirror finish, good polishing performance, excellent rust and acid resistance , heat treatment deformation is small.
Characteristics of S136; excellent corrosion resistance, excellent polishability, excellent wear resistance, excellent machinability, and excellent stability when hardened. Combining the above advantages, S136 has excellent production characteristics, and plastic molds with excellent corrosion resistance have the following characteristics: ①. Lower maintenance costs. After long-term use of the mold, the surface of the mold cavity still maintains its original appearance. Smooth state, the mold does not require special protection when operated or stored in humid environments. ②. Lower production cost: the mold will not corrode due to the influence of cooling water, and the life of the mold can be increased due to a certain cooling cycle. S136 can be applied to all molds. Due to its special properties, it is more suitable for the needs of special environments.
10. Sweden 8407 hot die-casting mold negative steel
Factory status: annealed HB≤180
Steel characteristics: clean and uniform steel, good structure, durable Forged by a 3000-ton press, it has high punching strength. After ultrasonic testing, the black skin on the surface has been removed by processing. It has high material utilization and can reduce processing costs.
It has the best hardness and good edge sex.
Uses: For making die-casting scratches, nozzles, extrusion axes, etc. for zinc, aluminum, tin and other non-ferrous alloys and copper alloys. It can be used as hot forging or stamping dies. After quenching, it can be made into high-grade Permanent production of plastic molds.
11. Swedish DF-2 constant wear-resistant oil steel, commercial name: Swedish oil steel Factory status: annealed ≤ HB190
Uses: Widely used, to be made into cold work Tools and dies, cutting tools, plastic mold inserts, knuckle embossing dies, measuring tools and forming tools.
12. Japanese NAK80
Factory status: HB370-400
Steel features: high-performance polished mirror steel, suitable for mirror plastic molds.
13. Japan Mitsubishi MUP (Advanced Plastic Mold Steel)
Factory hardness: pre-hardened to HB270-320
Features: Uniform hardness and metallographic structure , easy to achieve mirror polishing, pre-hardened plastic mold steel, uniform hardness through cutting, never deformed, due to low sulfur content, more suitable for spark erosion.
The characteristics of MUP series steel are: good purity, high wear resistance, good processing performance, suitable for etching, electro-etching and welding processing, and suitable for the production of various high-quality plastic molds.
The main reason why the mold deforms after mechanical processing is caused by the residual stress inside the steel.