The hardness of NM450 vs mild steel hot rolled

    
    Mild steel and NM450 both have unique mechanical and physical properties unique to steel alloys. While both are constructed from iron and carbon, the difference in their chemical compositions and production processes can create vast differences in their usability in certain applications.
    
    Mild steel, also known as low-carbon steel, is typically composed of between 0.05% and 0.20% carbon. This combination creates a relatively soft material, making it an ideal choice for many applications such as the production of automotive parts and in the construction industry. Though mild steel can be hardened and strengthened through heat treatment, it is not as hard nor as durable as some other steels.
    
    NM450, also known as wear-resistant steel, is a specific category of steel that contains between 0.7%-1.20% carbon as well as other alloying elements. This combination makes it much harder and more resilient to wear than mild steel. It also offers superior impact resistance, making it an ideal choice for parts in motors, mining and construction industries.
    
    When exploring the hardness of each type of steel, both the Rockwell Hardness Test (HRB) and the Vickers Hardness Test (HV) are used. The Rockwell Hardness Test measures the resistance of a material to imprinting from an indentor when a certain amount of force is applied to it. The Vickers Hardness Test, however, measures the resistance of a material when a diamond indenter is pressed into it. This is a much more precise measure of hardness.
    
    When evaluated in the Rockwell Hardness Test, mild steel typically has an HRB between 80 - 130, with the higher end closer to 130 indicating greater hardness. In comparison, NM450 steel averages around 350 - 420 HRB. This significant increase in hardness and resilience is due to its higher carbon content.
    
    In the Vickers Hardness Test, mild steel typically falls between 160 and 190 HV. However, NM450 steel registers much higher at an average of 550 - 650 HV. This indicates that NM450 steel is far more resistant to wear and can handle much more rigorous impacts before becoming scratched or dented.
    
    Overall, NM450 steel offers a far superior level of hardness and wear resistance compared to mild steel. As a result, it is much better suited for high-pressure and high-wear applications. Mild steel still remains a popular choice due to its low cost and great formability. However, in cases where greater wear resistance and durability are needed, NM450 steel has become the material of choice for many manufacturers.