The concept of metal hardness is proposed by French scientist Reaumur in the 18th century and being widely used for the quality test of finished and semi-finished products in the industrial production as the most frequent-used index ever since. Testing methods for metal hardness are divided into : Brinell hardness tester, Rockwell hardness tester, Vickers hardness tester, Shore hardness tester, Leeb hardness tester, Knoop hardness tester, Webster hardness tester and Barcol hardness tester,etc. Every test method for metal hardness has its corresponding testing equipment so we are going to introduce some common testing methods and their corresponding hardness testers.
Brinell hardness tester is a hardness-test method which is under the action of detection force, impressing the Tungsten Carbide Ball of a certain diameter to the surface of the sample, keeping it for some time then measure the pressure diameter when the detection force is removed. The hardness of the piece is measured by the diameter of the indentation.
The Brinell hardness tester in domestic market mainly includes the dynamic and static afterburner portable Brinell hardness tester and magnetic Brinell hardness tester.
Dynamic afterburner portable Brinell hardness tester can divided into three types: impact Brinell hardness tester, hammer Brinell hardness tester and pin Brinell hardness tester. Among the three, the cost performance of pin portable Brinell hardness tester is better than the other two. The quality and reliability of PHB-150 difunctional pin Brinell hardness tester produced by Shenyang Tianxing company has reached international-advanced level and sells well both at home and abroad. Static afterburner portable Brinell hardness tester mainly refers to the C type and hydraulic Brinell hardness tester. These two testers are small in volume and size thus can replace the Leeb hardness tester which is of poor reliability in production site. The prevailing hydraulic hardness tester in China is the PHB-3000 which uses 3000kg test force and 10mm TCB. In order to satisfy the domestic needs of industrial production, we can only depend on import in old days, but with the hydraulic Brinell hardness tester produced by Tianxing company, it can compare favorably with King Brinell hardness tester of America in quality and test reliability. In domestic market, the PGB-3000 of Tianxing is more time -effective than King in after-sale repair and maintenance, in the meantime, the price is more favorable. Magnetic portable hardness tester was initiated by Tianxing. This series of products uses a high-precision sensor and advanced displacement measurement technology. The digital display model uses automatic detection, namely, it can display in the screen of the equipment without measuring the indention diameter of the piece after removing the detection force.
Rockwell hardness tester
Rockwell hardness tester using 120° diamond cone, quenching steel ball, HBW(diameter stipulated) as indenter, with the total test force of initial force and main force, pressing the indenter into the surface of the sample then remove the main force afterwards. It is a hardness test method measuring the depth increment of indentation when the initial test force is reserved.
Divided by application method: C type Rockwell hardness tester, Rockwell superficial hardness tester and comprehensive Rockwell hardness tester.
The C type Rockwell hardness tester is a kind of small portable tester whose opening size is decided by the size of the tested piece. The prevailing types are: PHR-4-3, opening size 100mm*75mm, PHR-8-4,opening size 200mm*100mm, PHR-8-10,opening size 200mm*250mm, PHR-20-12, opening size 500mm*300mm. Rockwell superficial hardness tester usually is used for the test of small parts, such as hardness test for tinplate, sheet steel, copper strips, aluminum strips and hardware. Comprehensive hardness tester refers to the tester with a variety of hardness testing function, such as Brinell hardness tester.