Project Description
DIN1.2312 is a plastic mould tool steel which has Cr-Mn-Mo as strengthening elements as per Germany standard.Compared with DIN 1.2311,it has a little higher sulphur content, which offers better machineability,30% increase in milling speed and 300% increase in drilling speed can be expected.DIN 1.2312 is generally supplied in hardened and tempered condition with tensile strength 880-1080 Mpa
1.Supply Form & Size & Tolerance
| Supply Form | Size(mm) | Process | Tolerance | |
Round | Φ6-Φ100 | Cold Drawn | Bright/Black | Best H11 |
Φ16-Φ350 | Hot Rolled | Black | -0/+1mm | |
| Peeled/ground | Best H11 | |||
Φ90-Φ1000 | Hot Forged | Black | -0/+5mm | |
| Rough Turned | -0/+3mm | |||
Flat/Square/Block | Thickness :120-800 | Hot Forged | Black | -0/+8mm |
| Width:120-1500 | Rough Machined | -0/+3mm | ||
Remark:Tolerance can be customized as per requests
2.Chemical Composition
| Grade | C | Mn | P | S | Si | Cr | Mo |
| 1.2312 | 0.35-0.45 | 1.4-1.6 | ≤ 0.03 | 0.05-0.1 | 0.3-0.5 | 1.8-2.0 | 0.15-0.25 |
3.Relevant Standards
USA:P20+S
Germany:40CrMnMoS8-6
France: 40CMD8S
4.Physical Property
| Density, g/cm3 | 7.85 | ||
| Specific heat J/kg·K | 470 | ||
| Thermal expansion coefficient 10 ^-6m/(m·K) | 20-100°C | 20-200°C | 20-300°C |
| Annealed | 12.5 | 13.4 | 13.9 |
| Tempered | 12.3 | 13 | 13.7 |
| Thermal conductivity W/(m · K) | 100°C | 200°C | 300°C |
| Annealed | 40.2 | 40.3 | 39 |
| Tempered | 39.8 | 40.4 | 39 |
5. Mechanical Property
| Mechanical Property at Quenched and Tempered condition | |||||
| Tensile Strength | Yield Strength | Elongation | Reduction of Area | Impact | Hardness |
| 960Mpa | 850Mpa | 10% | 45% | 20J | 300HB |
6.Forging DIN1.2312
DIN1.2312 steel forging temperature:850 – 1100°C ,cooling as slowly as possible in sand after forged.
7.Heat Treatment
- Normalizing: 850 – 900°C,Cooling in air
- Annealing:700 – 740°C,Cooling in furnace,Hardness:max 235HB
- Hardening:840 – 880°C,water or oil quench
- Tempering:640 – 680°C,Cooling in air
| Chart of tempering values depending on the hardness | |||||||
| °C | 100 | 200 | 300 | 400 | 500 | 600 | 700 |
| HRC | 51 | 50 | 48 | 46 | 42 | 36 | 28 |
| R ， N/mm2 | 1730 | 1670 | 1570 | 1480 | 1330 | 1140 | 920 |
8.Application
DIN1.2312 tool steel is used for the production of moulds where improved machinability is required,and for plastics processing and moulds for pressure die casting.Typical applications include die holders, zinc die casting dies, backers, bolsters and injection moulds,machine construction, jigs, base plates, assembling parts, moulding frames, plastic moulds, plastic processing, die casting moulds, hydroforming tools, recipient sleeves, folding bars, tool holders,etc.
