1. Steel Description and Applications
Quard 450 is a martensitic abrasion resistant steel, with an average hardness of 450 HBW. It offers very high resistance to abrasive wear and impact granting a longer service life. The combination of very good cold forming properties and excellent weldability makes Quard 450 an optimal choice for most wear applications.
Applications:
- On-road tipper and dumper bodies
- Cement drum mixer barrels
- Refuse haulers, scrap containers
- Buckets, knives
- Feeders, skips, screw conveyors
- Mining and earthmoving machinery
2. Technical Characteristics
Hardness Guarantee: 420 – 480 HBW (Brinell hardness test according to EN ISO 6506-1)
Other mechanical properties (typical values):
| Test | Value |
|---|---|
| Charpy-V Notch Impact | 40 J (longitudinal at -40°C) |
| Yield Strength | 1250 MPa |
| Tensile Strength | 1400 MPa |
| Elongation (A5) | 10% |
3. Dimensions
Thickness: 3.2 – 64 mm
Width: 1500 – 3100 mm
4. Flatness, Tolerances & Surface Properties
- Flatness: EN 10029 Class N (standard) & Class S PLUS – exceeds EN 10029 Class A
- Thickness Tolerance: tighter tolerances on request
- Shape, Length, Width: meets EN 10029
- Surface Properties: exceeds market standards (EN 10163-2 Class B3 PLUS)
5. Delivery Conditions
Quard plates are delivered shotblasted and primed (low zinc silicate primer). Plates can also be supplied unpainted.
Chemical Composition (max %)
| Thickness | C | Si | Mn | P | S | Cr | Ni | Mo | B |
|---|---|---|---|---|---|---|---|---|---|
| 3.2 – 20 mm | 0.20 | 0.60 | 1.40 | 0.025 | 0.010 | 0.20 | 0.10 | 0.25 | 0.005 |
| 20.1 – 40 mm | 0.21 | 0.60 | 1.60 | 0.025 | 0.010 | 0.75 | 0.10 | 0.30 | 0.005 |
| 40.01 – 64 mm | 0.23 | 0.60 | 1.60 | 0.025 | 0.010 | 1.30 | 0.50 | 0.50 | 0.005 |
Carbon Equivalent (typical %)
| Plate Thickness | CEV | CET |
|---|---|---|
| 3.2 – 7.99 mm | 0.41 | 0.30 |
| 8 – 20 mm | 0.41 | 0.32 |
| 20.01 – 40 mm | 0.56 | 0.37 |
| 40.01 – 64 mm | 0.64 | 0.40 |
6. Heat Treatment
Quard 450 receives its properties by quenching and tempering. Properties are not retained if exposed above 250 °C. Not intended for further heat treatment.
7. Ultrasonic Testing
From 8 mm thickness and up, all plates are UT tested (Class S2, E2 according to EN 10160).
8. General Processing Recommendations
Thermal Cutting:
Plasma and flame cutting possible up to 40 mm (ambient temperature above 0 °C). Let parts cool slowly to reduce cracking.
Cold Forming:
Quard 450 is well suited for cold forming. Recommended bending ratios:
| Thickness (mm) | Transverse (R/t) | Longitudinal (R/t) | Trans. Width (W/t) | Long. Width (W/t) |
|---|---|---|---|---|
| < 8 | 3.5 | 4.0 | 10 | 10 |
| 8 – 20 | 4.0 | 5.0 | 10 | 12 |
| > 20 | 5.0 | 6.0 | 12 | 14 |
Welding:
Good weldability due to low carbon equivalent. Weld at ambient temp ≥ +5 °C. Interpass temp ≤ 225 °C. Use soft, low hydrogen consumables.
Machining:
Good machinability with HSS/HSS-Co drills. Use cemented carbide inserts for milling/countersinking.