Visão geral do aço NM450 e AR450

NM450:

Origina da China, onde é amplamente fabricado.
“Novo México” significa “Aço resistente ao desgaste” nos padrões chineses.
O “450” representa seu valor nominal de dureza, normalmente ao redor 450 HBW (Dureza Brinell).

AR450:

Uma nota reconhecida mundialmente, especialmente sob os padrões americanos.
“RA” significa “Resistente à abrasão.”
De forma similar, “450” indicates a hardness value of approximately 450 HBW.

Especificações

Especificações	AR400 / 400F	AR450 / 450F	AR450 / 500F
Dureza (Bnn)	400 (360 min.)	450 (429 min)	500 (450 min.)
Carbono (Máx)	0.20	0.26	0.35
Manganês (Mínimo)	1.60	1.35	1.60
Fósforo (Máx)	0.030	0.025	0.030
Enxofre (Máx)	0.030	0.005	0.030
Silício	0.55	0.55	0.55
Cromo	0.40	0.55	0.80
Outro	Additional Alloying elements may be added for enhancing abrasion resistant properties.	Additional Alloying elements may be added for enhancing abrasion resistant properties.	Additional Alloying elements may be added for enhancing abrasion resistant properties.
Size Range	3/16″ – 3″ (Widths 72″ – 96″ – 120″)	3/16″ – 3″ (Widths 72″ – 96″ – 120″)	1/4″ – 2 1/2″ (Widths 72″ and 96″)

Principais diferenças

1. Composição Química

NM450:
NM450 often contains higher carbon and alloying elements like chromium, molibdênio, e manganês. These contribute to excellent wear resistance and hardenability. No entanto, it may be slightly less weldable due to its chemical makeup.
AR450:
AR450 tends to have a more balanced composition, offering good weldability and forming capabilities. The alloying elements are optimized for both toughness and abrasion resistance.

2. Manufacturing Standards

NM450 adheres to Chinese standards (por exemplo, GB/T 24186-2009), while AR450 complies with international or American standards like ASTM or EN.
AR450 plates are often certified for stricter tolerances and more uniform mechanical properties.

3. Dureza e resistência ao impacto

AR450 generally exhibits higher toughness, making it better suited for applications where impact loads are present.
NM450 is designed primarily for abrasion resistance, and its toughness may be slightly lower in comparison.

4. Weldability and Formability

AR450 is typically easier to weld and form, thanks to its balanced chemical composition.
NM450, while weldable, requires preheating and post-welding treatments to minimize cracking due to its higher carbon content.

5. Cost and Availability

NM450 is often more cost-effective, especially in markets where Chinese steel is readily available.
AR450 can be more expensive, but it offers consistent quality and adherence to global standards.

Similarities

Both NM450 and AR450:

Deliver excellent resistance to abrasion and wear.
Are commonly used in industries like mining, construção, e manuseio de materiais.
Feature hardness levels around 450 HBW, making them suitable for heavy-duty applications.
Pode ser cortado, soldado, and shaped with proper tools and techniques.

Aplicações

Aplicações NM450

Excavator buckets and blades.
Wear liners for mining and quarrying equipment.
Conveyor systems and truck bodies.
Components exposed to severe abrasive conditions.

Aplicações AR450

Dump truck beds and chassis.
Construction equipment parts, such as bulldozer blades and loader buckets.
Heavy machinery subjected to both abrasion and impact.
Material transport systems.

Conclusão

Choosing between NM450 and AR450 depends on the specific requirements of your application. If cost efficiency and abrasion resistance are priorities, NM450 may be the ideal choice. Por outro lado, para aplicações que exigem um equilíbrio de resistência ao desgaste, resistência, e certificação global, AR450 se destaca como uma opção confiável.

Compreender as propriedades e limitações de cada classe garante desempenho e longevidade ideais em ambientes exigentes.