Test Background
The Rockwell hardness test of metal materials is based on the depth of plastic deformation of indentation to determine the hardness value, with 0.002 mm as a hardness unit. The advantage of the Rockwell hardness test is that it is quick and easy to operate, and the hardness value can be read directly from the dial. Because the air pressure is very small. Therefore, the hardness of thinner workpieces can be measured repeatedly.
The disadvantage is that the accuracy is poor and the hardness value fluctuates greatly. Usually, it should be measured several times at different parts of the sample, and the average value is the hardness value of the material.
Zhongke Testing Reliability Experiment Center has the capabilities of environmental testing and reliability performance testing of various metal materials, and provides professional Rockwell hardness testing services for metal materials.
Scope of tests
Metal materials are divided into ferrous metals and non-ferrous metals. The ferrous metals include iron, copper, manganese and steel.
Non-ferrous metals include tin alloys, aluminum alloys, magnesium alloys, copper alloys, aluminum alloys and zinc alloys.
Test method
Press an indenter of specific size, shape and material into the surface of the specimen in two levels of test force in accordance with the provisions of Chapter 7. After the initial test force is loaded, measure the initial indentation depth.
Then the main test force is applied, and the final indentation depth is measured while maintaining the initial test force after the main test force is removed. The Rockwell hardness is calculated according to the difference h between the final indentation depth and the initial indentation depth and the constants N and S through formula (1):
Rockwell hardness=N-h/S
The shallower the indentation depth of a material, the higher its Rockwell hardness. On the contrary, the Rockwell hardness is lower.
There are three commonly used Rockwell hardnesses: HRA, HRB and HRC, among which HRC is the most widely used.
Test standard:
GB/T 230.1-2018 Metallic materials Rockwell hardness test Part 1: Test method
ISO 6508-1: 2016 Metallic materials Rockwell hardness test Part 1: Test method
GB/T 230.2-2018 Metallic materials Rockwell hardness test Part 2: Inspection and calibration of hardness tester
GB/T 230.3-2018 Metallic materials Rockwell hardness test Part 3: Calibration of standard hardness block
BS EN ISO 3738-1-2010 Hard metals Rockwell hardness test (Grade A) Test method
ISO 3738-1-1982 Carbide Rockwell hardness test (A scale) Part 1: Test method
EN ISO 3738-2-2006 Carbide Rockwell hardness test (Scale A) Part 2: Preparation and calibration of standard test blocks
