VR300
Main characteristics and applications
VR300 is a pre-hardened steel with excellent hardening penetration up to thickness 600mm. To be used for plastic dies with excellent surface
finishing properties, compression moulding, plastic injection moulds, moulds for automotive industry with texturing.
VR300 is designed to provide improved performance and offers the following advantages:
• uniform hardness across the full thickness up to 600mm.
• high polishability.
• high machinability.
• excellent suitability for texturing.
• greatly increased thermal conductivity.
• good toughness.
Comparable standards
| DIN | W.Nr | JIS |
|---|---|---|
| VR300 | - | - |
Chemical composition (typical; in weight %)
| C | Si | Mn | P (max) | S (max) | Cr | Mo | Ni |
|---|---|---|---|---|---|---|---|
| 0.35-0.45 | 0.020-0.30 | 1.40-1.60 | 0.030 | 0.030 | 1.80-2.00 | 0.15-0.25 | 0.60-0.70 |
Production technology
EAF – LF – VD - Forging – Rolling - Heat treatment QT
US specification
In according to standard EN10228-3 Class 4 and standard SEP 1921 Class E/e
Delivery condition
VR300 is delivered in quenched and tempered condition, with hardness range 280 - 325 HB (29 - 35 HRC).
Through hardenability
The high performance of hardenability for thickness 600 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 | 11.6 | 12.1 | 13.8 |
| Thermal conductivity (W/mk) | 40.0 | 39.3 | 38.4 | 35.2 |
| Young modulus (Kn/mm2) | 205 | 201 | - | - |
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 | In the range 530 – 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
Tool and Die Steel Includes Cold Work Steel, Hot Work Steel, Plastic Mould Steel, High Speed Steel. These tool materials adhere to great quality demands of steel like temper, strength, toughness, resistance to tempering, hardening capacity, dimensional stability etc. The range of Tool Steel in our store includes products from renowned manufacturers.