Wear Resistance of H450 and NM450 Low Alloy Steel

High strength low-alloy (HSLA) steel is one of the most widely used materials in engineering, due to its excellent mechanical properties, resistance to wear and corrosion, and low cost. It is commonly used in applications such as automotive components, bridges, shipbuilding, construction equipment, and power plants. In this article, we will compare two specific grades of HSLA steel, H450 and NM450. We will discuss their wear-resistance properties, and how they compare to one another.

Comparative Properties of H450 and NM450 Steel
H450 and NM450 are both high-strength low-alloy steels, and they share many of the same mechanical properties. Both steels have a tensile strength of 1500 MPa, and a hardness of about 420 HB. Both steels are relatively good conductors of heat and electricity, as well as being highly corrosion-resistant. Additionally, these steels also have good weldability. The difference between these two steels lies in their wear-resistance properties.

H450 is a high-strength low-alloy steel developed for applications where high strength is paramount. To increase its strength, H450 has been alloyed with additional elements such as vanadium, chromium, and molybdenum. These additional elements allow H450 to be hardened and tough, as well as giving it excellent wear-resistance properties. This wear-resistance makes H450 an excellent choice for applications where there is a high level of wear, such as excavators and other off-highway vehicles.
    
NM450 is a high-strength low-alloy steel developed for applications where wear-resistance is paramount. To increase its wear-resistance, NM450 has been alloyed with additional elements such as nickel, manganese, and chromium. These additional elements give NM450 a higher level of wear-resistance than H450, making it an excellent choice for applications involving high levels of friction, such as conveyor systems and other heavy machinery.
    
Comparative Wear Resistance of H450 and NM450
The wear-resistance of a material is determined by its ability to resist abrasive wear. The material must be able to resist the cutting, gouging, and scratching of hard surfaces. As such, wear-resistance can be measured by testing the material's ability to withstand abrasion, friction, and impact. H450 and NM450 have been tested according to ASTM G65 wear testing, which measures the weight loss of a material after being abraded on a wheel. The results of these tests have shown that, while both materials are highly wear-resistant, NM450 is more resistant to wear than H450.
    
NM450 has a wear-resistance index of 42 g/cm2, while H450 has a wear-resistance index of 35 g/cm2. This means that, under the same conditions, NM450 will resist wear for a longer period of time compared to H450.
    
H450 and NM450 are both high-strength low-alloy steels, with similar mechanical properties and weldability. The main difference between these two steels is their wear-resistance properties. NM450 has a higher level of wear-resistance than H450, making it more suitable for applications involving high levels of abrasive wear.

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