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Durómetro Brinell

QATM's Brinell Hardness tester range comprises models for both micro and macro hardness testing. All models are suitable for multiple test methods in addition to Brinell testing and range from semi-automatic operation to full automation. QATM products are characterized by operating comfort, sophisticated engineering and accurate results.

Microdurómetro Brinell Rango de fuerzas de ensayo: 0.25 g – 62.5 kg

Macrodurómetro Brinell Rango de fuerzas de ensayo: 0.3 kg – 3000 kg

Durómetro Brinell totalmente automático Rango de fuerzas de ensayo: 0.3 kg – 3000 kg

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Información de trasfondo Ensayo de dureza Brinell (DIN EN ISO 6506)

Johann August Brinell (Suecia) presentó su nuevo método de ensayo de dureza en la exposición mundial de París en el año 1900.

En este método, una bola de carburo se presiona verticalmente sobre la superficie de una muestra con una fuerza determinada, creando así una indentación en la superficie de la muestra. El diámetro de la indentación d se determina con un microscopio de medición y la dureza Brinell se calcula o se consulta en las tablas correspondientes.

1. Indentation of a hard metal ball with ØD and test force F in the specimen

Indentation of a hard metal ball with ØD and test force F in the specimen

2. Measurement of the indentation with diameter d

Measurement of the indentation with diameter d

Calculation of the Brinell Hardness

Calculation formula for Brinell hardness:

Calculation of the Brinell Hardness


For the Brinell hardness test, the selection of suitable test parameters is of decisive importance.

The Brinell method becomes inaccurate for very small or very large penetration depths. For this reason, the test load must be selected such that the following conditions are met for the mean indentation diameter:

0,24 * D < d <0,6 * D

In order to meet these conditions, 'Stress level B' was introduced. This depends on the material group to be tested.

Calculation of the Brinell Hardness


The stress level is selected according to the following table: 

Stress level B for Brinell Hardness Testers

 

Material

Stress level B [N/mm²]

Ball diameterD [mm]

Test forceF [N]

Recordable Hardness Range [HBW]

Steel and cast steel

Nickel and titanium alloys

Cast iron ≥ 140 HBW

Cu and Cu alloys ≥ 200 HBW

30

1
2,5
5
10

2,94,2
1839
7355
29420

95 – 650

Light metals and their alloys ≥ 35 HBW

 

15

1
2,5
5
10

-
-
-
14710

48 – 327

Cast iron < 140 HBW

Cu and Cu alloys

350-200 HBW

 

10

1
2,5
5
10

98,07
612,9
2452
9807

 32 – 218

Cu and Cu alloys < 35 HBW

Light metals and their alloys

≥ 35 < HBW <  80 

5

1
2,5
5
10

49,03
306,5
1226
4903

16 – 109

Light metals and their alloys ≥ 35 HBW

2,5

1
2,5
5
10

24,52
153,2
612,9
2452

8 – 55

Lead and tin

1

1
2,5
5
10

9,807
61,29
245,2
98,7

3 – 22

According to DIN EN ISO 6506
Only ball diameters >1 mm may be used for testing cast iron

After the degree of stress has been determined, test load F and ball diameter D can be determined according to the table. In principle, the ball diameter should be as large as possible in order to cover
as large and therefore representative a part of the sample surface as possible.

Hardness values determined with different ball diameters at the same degree of loading can only be compared to a limited extent. Hardness values determined with the same ball diameter but different degrees of loading are not comparable. Therefore, it is essential that all parameters are always specified when specifying a hardness value.

Brinell Hardness testing Results

According to DIN EN IS 6506-1 the result of a Brinell hardness test is indicated as follows:

310 HBW 2,5 / 187,2 / 20   ⇒   Hardness value as per Brinell

310 HBW 2,5 / 187,2 / 20   ⇒   Abbreviation for Brinell hardness

310 HBW 2,5 / 187,2 / 20   ⇒   Ball diameter in mm

310 HBW 2,5 / 187,2 / 20   ⇒   Test force [N] = 9.807 * test force specification

310 HBW 2,5 / 187,2 / 20   ⇒  

Application time of the test force 
(omitted if it is between 1-15 s)

Further prerequisites for Brinell hardness testing

More prerequisites need to be fulfilled for standard-compliant testing:

Further prerequisites for Brinell hardness testing

Test temperature

  • normal requirements: 10°C bis 35°C
  • high requirements: 23°C ± 5°C

Distances between the indentations and from the edge

  • a ≥ 2,5 * d
  • b ≥ 3,5 * d