Measuring hardness is a fundamental process in assessing how well an alloy will stand up to wear and tear. It is particularly crucial in the characterisation and designation of abrasion resistant steels, as hardness essentially determines resistance to scratching and impacting forces. Several distinct measures of hardness exist, but the Brinell scale is one of the most well-established in materials characterisation. It has become so ubiquitous in fact, that abrasion resistant steels are often named for the Brinell scale designation: 300 Brinell Steel, for example.
Explaining the Brinell Scale
The Brinell scale characterises hardness as a function of load-dependent penetration by an indenting implement. Indentation testing typically uses a small pyramidal probe to interrogate the surface of an alloy with a pre-defined mechanical load. A subsequent Brinell hardness number (BHN) is calculated using the applied load in kilogram-force (kgf), the diameter of the indenter, and the depth and diameter of material displacement below the indenter tip. Various indenter types are available depending on the material under observation. 300 Brinell is an extremely hard alloy that may be tested using the impact of a tungsten carbide ball as opposed to a small-scale diamond indenter.
Johan August Brinell’s indentation method and test calculation proved more popular than alternatives (Rockwell, Vickers, etc.) as the BHN can be reliably used to approximate the ultimate tensile strength (UTS) of high-strength steels.
What is 300 Brinell Steel?
300 Brinell, as the name suggests, is a steel alloy with a BHN of approximately 300. The actual mechanical value varies depending on the specific alloying composition and chemical concentration of key components. Typical chemical values for 300 Brinell steel include carbon (0.18%), chromium (1.50%), manganese (1.70%), molybdenum (0.50%), and nickel (0.40%) with additional trace elements.
The unique microstructure of 300 Brinell steel is characterised as a hardenable martensitic grade, which results in a nominal BHN of between 270 – 390. This is combined with excellent strength characteristics in terms of both yield (900 MPa) and tensile (1000 MPa) strengths. These properties make 300 Brinell steel extremely resistant to the effects of abrasion and elevated surface pressure.
Applications of 300 Brinell Steel
With an approximate BHN of 300 and exceptional strength ratings, 300 Brinell steels are utilised widely in heavy industry and earth-moving applications. Typical applications of the grade include:
- Earth moving and mining equipment
- Feeders, funnels, and hoppers
- Heavy-duty platform structures
300 Brinell Steel from Masteel
Masteel is the UK’s leading supplier of abrasion resistant steels for construction, industrial, and mining markets. Our proprietary 300 Brinell steel grade is MAS300AR, which is supplied in precisely cut lengths to suit your specifications.