BMS 3000-OBC, Руководство по эксплуатации

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1 General Description
Hardness is an important parameter of mechanical performances for metallic and alloy materials. It usually refers
to the resistance capacity of a material against the indentation of the other harder material with certain shape which
is pressed into its surface without residual deformation by itself.
Model 210HBS-3000 Brinell Hardness Tester
can be used to measure the Brinell hardness of
unquenched steels, cast irons, non-ferrous metals and other softer bearing alloys in the laboratories of factories,
research institutions and colleges.
2 Testing Principles
Brinell hardness testing is to apply specified test forces onto the surface of test specimen through a tungsten
carbide ball of certain diameter (Figure 1), retain it for a specified period of time, and then remove it and measure
the diameter of indentation on the surface of specimen. The Brinell hardness is shown by the average pressure
(kgf/mm
2
) on the surface area of ball impression on the specimen (Table 1) and calculated as per the following
formulation (1):
Brinell hardness=0.102* ……………… (1)
Table 1 Symbols and Descriptions
Symbols Descriptions Unit
D Diameter of tungsten carbide ball mm
F Test forces N
d Average diameter of indentation mm
d
1
, d
2
Diameters of indentations along two perpendicular directions mm
h Depth of indentation mm
HBW Brinell hardness HBW
Fig-1 Testing Principle diagram of Brinell hardness
To apply specified test forces onto the surface of test specimen through a tungsten carbide ball of certain diameter,
retain test force for a specified period of time, then remove it and measure the diameter of indentation on the
surface of specimen, referring to Fig-1.
For example, 350HBW5/750 means that the hardness is 350 measured with a tungsten carbide ball of diameter
5mm, under a test force of 750 kgf which is retained for 10 to 15 seconds.
*For details, please refer to GB/T 231.1-2002:
《
Metallic Brinell Hardness Test
》
.
3 Range of Application
The standard terms and conditions of Brinell Hardness Test often uses tungsten carbide ball indenter with a
diameter of 10mm and test force of 3,000 Kgf (Fig-2), which fully symbolizes the characteristics of Brinell
hardness. However, due to the fact that the specimens vary in hardness and size, one test force and one kind of ball
indenter can’t meet all the different requirements. Only when the ratio of test force divided by the square mean of
) (
2
2 2
d D D D
F
 
