ASTM E10

Full Name

ASTM E10 – Standard Test Method for Brinell Hardness of Metallic Materials

Scope

ASTM E10 is a widely used standard test method for determining the Brinell hardness of metallic materials. This measurement provides valuable insights into a material’s resistance to indentation, which is a crucial property for various applications.

Test procedure:

  • Sample preparation: the test surface must be smooth and free of defects to ensure accurate results. Any surface irregularities can influence the indentation and lead to inaccurate hardness measurements.
  • Indentation: a hardened steel ball indenter is pressed into the material’s surface with a specified load. The load is selected based on the expected hardness of the material, typically ranging from 500 kgf to 3000 kgf.
  • Measurement: the diameter of the resulting indentation is measured using a Brinell microscope or a calibrated measuring device. The accuracy of this measurement is critical for obtaining reliable Brinell hardness values.
  • Calculation: the Brinell hardness number (BHN) is calculated using a formula that takes into account the applied load, the diameter of the indenter ball, and the diameter of the indentation.

Factors affecting Brinell hardness:

  • Material composition: the chemical composition of the material significantly influences its Brinell hardness. Elements such as carbon, alloying elements, and impurities can affect the material’s resistance to indentation.
  • Heat treatment: the heat treatment process can alter the microstructure and properties of a material, including its Brinell hardness. Annealing, quenching, and tempering can all affect hardness.
  • Strain hardening: deforming a material can cause it to become harder due to strain hardening. This occurs when dislocations in the material’s crystal structure are hindered from moving, increasing the material’s resistance to deformation.
  • Grain size: the size and orientation of grains in a material can also influence its Brinell hardness. Fine-grained materials generally exhibit higher hardness compared to coarse-grained materials.

Applications of Brinell hardness testing:

  • Quality control: Brinell hardness testing is essential for ensuring the quality of metallic products. By measuring hardness, manufacturers can verify that materials meet specified standards and specifications.
  • Material selection: Brinell hardness can be used to select appropriate materials for various applications. For example, materials with high Brinell hardness are often chosen for components that require resistance to wear, abrasion, or indentation.
  • Process monitoring: Brinell hardness testing can help monitor manufacturing processes. By measuring the hardness of materials at different stages of production, manufacturers can identify and address any process variations or defects.
  • Research and development: Brinell hardness is a valuable tool for materials research and development. By studying the relationship between Brinell hardness and other material properties, researchers can gain insights into the behavior of materials and develop new materials with improved performance.

Resources

Keywords

Brinell hardness; metallic materials; test method; indentation; hardened steel ball; load; diameter; measurement; calculation; BHN; quality control; material selection; process monitoring; research and development; manufacturing; construction; inspection; structural components; materials; surface preparation; defects; strain hardening; grain size; heat treatment; material composition; factors affecting Brinell hardness; applications; testing services; ASTM E10