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What is the Brinell Hardness(HB)
- Jan 03, 2018 -

Brinell hardness (HB) is a certain size of the test load, a certain diameter of the hardened steel ball or cemented carbide ball into the 


metal surface to be tested, for a specified period, and then unloaded to measure the measured surface indentation diameter.Brinell hardness 


is the quotient of the load divided by the indentation spherical surface area. Generally: a certain load will be a certain size of a hardened 


steel ball pressed into the surface of the material for a period, to load, the load and its indentation area ratio, that is Brinell hardness 


(HB), in kilograms of force /mm² (N /mm²)


Brinell hardness range is 8 ~ 650HBW. As the metal material is hard and soft, the workpiece is thick and thin, large and small, if only a 


standard test force F and head diameter D, there will be some workpiece and material does not meet phenomenon. Therefore, in the production 


of Brinell hardness test, requires the use of different sizes of test force and pressure head diameter, the same material with different F 


and D were tested, can get the same Brinell hardness value, the key In the similarity of indentation geometries, some matching relationship 


between F and D can be established to ensure the stability of Brinell hardness.For some metallic materials, the tensile strength value can be 


roughly determined from the Brinell hardness value.


Rockwell hardness test requirements of the sample specimen, the thickness of not less than 10 times the depth of the indentation depth, the 


specimen back can not be obvious deformation marks. The thickness of the sample thus determines the choice of load and the load must ensure 


that the deformation caused is less than the minimum thickness of the sample. For each hardness test, there is a minimum measurable 


thickness.


Brinell hardness measurement is mainly based on manual testing methods, so consume a lot of manpower, but also can not guarantee the quality 


of testing. In order to eliminate the interference of human factors in the detection of Brinell hardness indentation and improve the 


measurement accuracy, the local structural features are firstly extracted from the target area and then the SVM classifier queue is used to 


describe the target appearance model. Secondly, to establish the target spatial context model, Describes the spatial relationship between the 


target area and the surrounding local context area, and updates the space-time context model of the next frame image by using the spatial 


context model for the continuous target tracking. The appearance model makes full use of the target information, the spatial-temporal context 


information Tracking full use of the target contextual information, the two complement each other and achieve the more stable target 


tracking.


Brinell hardness measurement method for cast iron, non-ferrous alloys, a variety of annealed and tempered steel, not too hard, too small, too 


thin and the surface does not allow large indentation specimens or workpieces. National Standard (GB231-84) provides Brinell hardness test, 


the commonly used 0.102F / D ratio of 30,10,2.5 three, according to the type of metal material, the hardness range and thickness of the 


sample according to the following table ( Brinell hardness test specification) Select the diameter of the test head (steel head) D, test 


force F and holding time. Our equivalent implementation of international standards ISO6506, developed a new national standard: GB / T231.1-


2002, the article explicitly abolished steel ball pressure head, all with carbide ball head. Therefore, HBS stop using, all with HBW said 


Brinell hardness symbol.

Brinell hardness measurement has the advantages of high measurement accuracy, indentation area, can reflect the average hardness of the 


material in a larger range, the measured hardness value is more accurate, data repeatability is strong.