Hardness and their testing

- Oct 16, 2018-

     Hardness is the performance index to measure the soft and hard degree of the material.It is a comprehensive performance index of a series of different performance combinations such as elasticity, plasticity, deformation reinforcement, strength and toughness.
Test Tools and Ingredients
Hardness tester
Steel ball
Methods/steps
Rockwell hardness (HR) is the most commonly used hardness measurement method.The three scares of Rockwell hardness are HRC, HRA and HRB.
What is rockwell hardness, brinell hardness, vickers hardness ?
Brinell hardness (HB), made of hardened steel ball as the hardness head, coupled with a certain test force artificial part surface, after the test force is removed, the diameter of the indentation is measured, and then the table or calculation is made to obtain the corresponding brinell hardness value HB.
Vickers hardness (HV), using the hardness of the head is a diamond pyramid with a square ground, vertebral body relative Angle between two sides is 136 °, and indentation hardness value is equal to the test force ratio of surface area.
Application:
Brinell hardness is commonly used for the hardness of metallic materials with coarse grain or constituent phases, such as cast iron, alloy steel, copper and copper alloys, lead, tin, light metals, etc.
Rockwell hardness is used to quench steel, annealed steel, aluminum alloy and other slightly soft alloy and metal.
Vickers hardness is used to test small parts, check the treatment effect of oxidation, nitriding, carburizing and coating.In addition, brittle materials such as glass, agate and ceramics are generally represented by vickers hardness.

Notice:
Brinell hardness is the hardest, rockwell hardness is less than brinell hardness, and vickers hardness is less than the first two kinds of hardness.It is a comprehensive performance index of a series of different performance combinations such as elasticity, plasticity, deformation reinforcement, strength and toughness.

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