HRB？ It is the hardness obtained by the hardened steel ball with a load of 100Kg and a diameter of 1.5875mm, and is used for materials with lower hardness. For example: low carbon steel, non-ferrous metals, annealed steel, etc.
HRC？ It is the hardness obtained by using 150Kg load and diamond cone press, and is used for materials with higher hardness. For example: hardened steel, cast iron, etc.
Difference:
1, with different application ranges.
The application range of HRC scale is 20~70HRC.
The application range of HRB ruler is 20 ~100 HRB.
2. The types of measurement are different.
HRB ruler is mainly used to measure the hardness of low-hardness parts, such as nonferrous metals, alloys and annealed steel.
HRC straightedge is mostly used to measure the hardness of quenched and tempered samples such as carbon steel, tool steel and alloy steel.
3. The test materials are different.
The HRC scale is used to test hardened steel, tempered steel, quenched and tempered steel and some stainless steels. This is the most widely used hardness testing method in metalworking industry.
HRB ruler is used to test various annealed steels, normalized steels, low carbon steels, some stainless steels and hard copper alloys.
Extended data:
Difference and transformation
Hardness of steel: the code name of metal hardness is H.
● Conventional expressions include Brinell hardness (HB), Rockwell hardness (HRC), Vickers hardness (HV) and Richter scale hardness (HL), among which HB and HRC are commonly used.
●HB has a wide range of applications, generally used in soft materials, such as non-ferrous metals, steel before heat treatment or after annealing. HRC is suitable for materials with high surface hardness. The scope of application of HRC is HRC 20-67, which is equivalent to HB 225-650.
The principle difference between them is that Brinell hardness is measured by indentation diameter, while Rockwell hardness (HR) is measured by indentation depth. Rockwell hardness indentation is very small, and the measured value is local. It needs to measure several points to get the average value. It is suitable for finished products and sheets and belongs to nondestructive testing. Cloth hardness indentation is large and the measured value is accurate, which is not suitable for finished products and sheets, and generally does not belong to nondestructive testing.
●HV- Suitable for microscope analysis. Vickers hardness (HV) is the value of Vickers hardness (HV) when the diamond square cone press with the load less than 120kg and the apex angle of136 is pressed into the surface of the material, and the load of the material indentation pit is divided by the surface area.
HL portable hardness tester, easy to measure. After the impact ball head impacts the hard surface, it will rebound; The hardness is calculated by the ratio of the rebound speed and impact speed of the punch at the distance from the sample surface1mm. The formula is Richter hardness HL= 1000×VB (rebound speed) /VA (impact speed), so the impact sound should be transparent.
● The most commonly used portable Richter hardness tester can be converted into Brinell (HB), Rockwell (HRC), Vickers (HV) and Shore (HS) hardness after being measured by Richter hardness tester (HL).
References:
Baidu encyclopedia-rockwell hardness