Piastra in acciaio resistente all'usura
In simple terms:
AR400 = ~400 Brinell hardness → balanced wear and toughness.
AR500 = ~500 Brinell hardness → harder and more wear-resistant, less easy to form or weld.
Selecting between these grades depends on whether the main concern is abrasione, impatto, O fabrication ease.
- Descrizione
In designations like AR400, AR500, O NM400, the numbers represent the approximate Brinell hardness (HBW) of the steel plate — which directly reflects its wear resistance level.
1. Meaning of the Numbers
| Grado | Approx. Durezza (HBW) | Descrizione |
|---|---|---|
| AR360 / NM360 | 320 – 380 | Lower hardness, suitable for applications requiring good formability and impact toughness. |
| AR400 / NM400 | 360 – 440 | Standard grade; excellent balance between wear resistance and workability. |
| AR450 / NM450 | 420 – 480 | Higher hardness for medium-impact, condizioni di elevata usura. |
| AR500 / NM500 | 470 – 540 | Durezza molto elevata; ideal for severe abrasion environments. |
| AR600 / NM600 | 560 – 620 | Extreme hardness for maximum wear life in the toughest conditions. |
2. Example Explanation
-
AR400 means:
The steel has an average Brinell hardness of about 400 HBW.
It provides excellent resistance to sliding abrasion while maintaining good toughness and weldability.
→ Commonly used in truck liners, tramogge, cade, and construction machinery. -
AR500 means:
The plate has a Brinell hardness of about 500 HBW, providing higher wear resistance than AR400.
Tuttavia, increased hardness slightly reduces toughness and formability.
→ Ideal for mining, cava, and heavy-impact applications like crushers and buckets.
3. Comparative Performance Table
| Proprietà | AR400 / NM400 | AR500 / NM500 |
|---|---|---|
| Durezza Brinell (HBW) | 360 – 440 | 470 – 540 |
| Forza di snervamento (MPa) | 1000 – 1250 | 1200 – 1400 |
| Resistenza alla trazione (MPa) | 1200 – 1400 | 1400 – 1700 |
| Impact Energy (-40 °C, J) | ≥ 27 | ≥ 20 |
| Lavorabilità (Taglio / Saldatura) | Bene | Moderare |
| Resistenza all'usura | Alto | Molto alto |
| Applicazioni tipiche | Cassoni di autocarri con cassone ribaltabile, tramogge, fodere | Attrezzature minerarie, fodere del frantoio, caricatori |
4. Key Takeaways
-
IL number (400, 500, ecc.) = approximate hardness in HBW.
-
Higher number → higher hardness and wear resistance, Ma lower ductility and weldability.
-
AR400/NM400 is preferred when both fabrication and wear resistance are needed.
-
AR500/NM500 is used for maximum wear life in high-abrasion environments.
