Main Characteristics and Applications
VR400 is a high hard tool steel ideal to produce block with thickness up to 1300mm in large size with an high performance of trough hardening homogeneity.
To be used for plastic injection moulds, compression moulds, big sizes moulds for automotive industry with texturing.
VR400 is designed to provide improved performance and offers the following advantages:
• uniform hardness across the full thickness up to 1300mm.
• high polishability.
• high machinability.
• excellent suitability for texturing.
• greatly increased thermal conductivity.
• improved weldability as W W.NR. 1.2738.
• good toughness.
Comparable standards
| DIN | W.Nr | JIS |
|---|---|---|
| VR400 | 1.2738 HH | - |
Chemical composition (typical; in weight %)
| C | Si | Mn | P (max) | S (max) | Cr | Mo | Ni |
|---|---|---|---|---|---|---|---|
| 0.27-0.30 | 0.03 | 1.50-1.60 | 0.010 | 0.001 | 1.20-1.40 | 0.45-0.60 | 1.05-1.20 |
Production technology
EAF – LF – VD - Forging – Heat treatment QT
US specification
In according to standard EN10228-3 Class 4 and standard SEP 1921 Class E/e
Delivery condition
VR400 is delivered in quenched and tempered condition, with hardness range 360 - 400 HB (39 - 43 HRC).
Through hardenability
The high performance of hardenability for thickness 1300 mm, is obtained by an optimized balance of chemical composition and a special manufacturing process.
Physical properties (reference values)
| 20°C | 100°C | 250°C | 500°C | |
|---|---|---|---|---|
| Thermal expansion coefficient (10-6/K) | 11.4 | 11.6 | 12.7 | 14.2 |
| Thermal conductivity (W/mk) | 36 | 36.7 | 38 | 34.3 |
| Young modulus (Kn/mm2) | 211 | 207 | 199 | 166 |
Heat treatment
| TREATMENT | TEMPERATURE | HOLDING TIME (HT) | COOLING | COMMENTS | |
|---|---|---|---|---|---|
| Annealing | Heat to 650 - 700 °C | Min. H.T. for 2 minute /mm | Air or furnace | In order to obtain hardness lower than 250 HB ( 24 HRC) to improve machinability | |
| Stress relieving | Heat to 500 - 550 °C | Min. H.T. for 2 minute /mm | Air or furnace | To be carried out after machining, is recommended to eliminate the residual stresses induced by mechanical working | |
| Hardening | Heat to 860-900°C | Min. H.T. for 1 minute /mm | Polymer | - | Tempering | Heat to 550 – 610°C | Min. H.T. for 3 minute /mm | Air or furnace | To be carried out after hardening. 2nd Tempering must be performed to max 30°C below tempering temperature |
C.C.T. Curve
Mechanical Properties
Tempering Curve
Polishing Range
Texturing Samples
Texturing performed by Standex Mold-tech with patterns Standex MT 9086, MT 9055 and 9083
