brinell hardness of carbon steel pipe,Technology

 Brinell hardness (HB) with a certain diameter of the steel balls or tungsten carbide balls, pressed into the pattern surface of a predetermined test force (F), after the predetermined hold time after drop test force, the diameter of the measurement sample surface indentation (L). Brinell hardness test force divided by the the indentation spherical surface area quotient. To HBS (Ball Ball Ball Ball) the unit N/mm2 (MPa). The formula is: where: F - pressed into the metal surface of the sample test force, N; D - test steel ball diameter, mm; d - indentation average diameter mm. Brinell hardness was measured more accurate and reliable, but generally HBS only applies 450N/mm2 (MPa) or less of a metal material, for the harder steel, or thin sheet NA. Steel standards, Brinell hardness is the most widely used, and often said that the hardness of the material, the indentation diameter d both intuitive and convenient.

Brinell hardness is the most widely used methods in carbon steel pipe hardness testing, . This method uses the earliest, due to its imprint, and thus the hardness values ​​affected by the sample organization microsegregation ingredients uneven minimal impact, test results points sprinkle a small degree, good reproducibility, can objectively reflect the objective hardness of the material.

Principle: In a predetermined detection force, a certain diameter of the steel ball is pressed into the specimen surface to maintain a certain time, and then removing the detected force, the pressure imprint diameter measurement on the specimen surface, can be calculated based on the diameter of the pressure imprint pressure marks the gravure area. Brinell hardness test force divided by the the indentation spherical surface area quotient. Unit 9.807N/mm. The indentation Big steel ball pressed into the deep, low hardness values​​; vice versa hardness values ​​to engage