When testing the hardness of carbon steel round bars with lower hardness, we should choose a hardness tester reasonably to ensure that the test results are accurate and effective. We can consider using the HRB scale of the Rockwell hardness tester.
The HRB scale of the Rockwell hardness tester uses a steel ball indenter with a diameter of 1.588mm and a matching test force of 100KG. The measurement range of the HRB scale is set at 20-100HRB, which is suitable for hardness testing of most carbon steel round bar materials with lower hardness.
1.If the carbon steel round bar has been quenched and has a high hardness of about HRC40 – HRC65, you should choose a Rockwell hardness tester. The Rockwell hardness tester is easy and quick to operate, and can directly read the hardness value, which is suitable for measuring high hardness materials.
2.For some carbon steel round bars that have been treated with carburizing, nitriding, etc., the surface hardness is high and the core hardness is low. When it is necessary to accurately measure the surface hardness, a Vickers hardness tester or a microhardness tester can be selected. The indentation of the Vickers hardness test is square, and the hardness value is calculated by measuring the diagonal length. The measurement accuracy is high and can accurately reflect the hardness changes on the material surface.
3.In addition to the HRB scale of the Rockwell hardness tester, the Brinell hardness tester can also be used to test low-hardness carbon steel round bar materials. When testing carbon steel round bars, its indenter will leave a large area of indentation on the surface of the material, which can more comprehensively and comprehensively reflect the average hardness of the material. During the operation of the hardness tester, the Brinell hardness tester is not as fast and easy as the Rockwell hardness tester. The Brinell hardness tester is the HBW scale, and different indenters match the test force. For carbon steel round bars with generally low hardness, such as those in the annealed state, the hardness is usually around HB100 – HB200, and the Brinell hardness tester can be selected.
4.For carbon steel round bars with large diameter and regular shape, various hardness testers are generally applicable. However, if the diameter of the round bar is small, such as less than 10mm, the Brinell hardness tester may affect the measurement accuracy due to the large indentation. At this time, Rockwell hardness tester or Vickers hardness tester can be selected. Their indenter size is smaller and can more accurately measure the hardness of small-sized samples.
5.For irregularly shaped carbon steel round bars that are difficult to place on the workbench of a conventional hardness tester for measurement, a portable hardness tester, such as a Leeb hardness tester, can be selected. It uses an impact device to send an impact body to the surface of the object being measured, and calculates the hardness value based on the speed at which the impact body rebounds. It is easy to operate and can perform on-site measurements on workpieces of different shapes and sizes.
Post time: Apr-14-2025
