What Is The Hardness Range of Precision Tube?

What is the hardness of precision tube?

Hardness refers to the ability of a material to resist plastic deformation, scratches and damage. Hardness is usually measured by a hardness tester. Hardness tests usually include indentation hardness tests, tensile hardness tests of metal materials, Rockwell hardness tests of rocks, etc.

The hardness of a precision tube refers to the ability of a precision tube to resist deformation and quickly return to its original shape under certain test conditions. Generally speaking, the greater the hardness, the higher the strength of the material, and the smaller the deformation capacity.

What are the hardness index requirements for precision tubes?

Precision tube hardness is generally divided into two types: surface hardness and internal hardness.

1. Surface hardness

Surface hardness refers to the hardness of the material surface after heat treatment, which can be tested by Rockwell hardness test method.

2. Internal hardness

Internal hardness refers to the hardness of the steel tube section or material, which is generally tested by Vickers hardness test method.

For different standards and different types of precision tubes, there are certain differences in their hardness indexes. For example, the Japanese JIS standard generally sets the hardness index of ordinary precision tubes with a thickness of d above 0.5mm to HRC61~65; while the German DIN standard sets the hardness index of similar precision tubes to between HRC55~58, and these standards also apply to other pipes, such as carbon steel pipe.

What is the hardness range of precision tubes?

The hardness of precision tubes depends on their heat treatment state and the materials used. The following are some common hardness ranges:

1. After quenching, not tempered

The hardness of 1.45# precision seamless steel pipe after quenching and before tempering is greater than HRC55, and can reach up to HRC62.

2. Low temperature tempering

The hardness after low temperature tempering is generally HRC58-64, which is mainly used to maintain high hardness and high wear resistance.

3. Medium temperature tempering

The hardness after medium temperature tempering is generally HRC35-50, which is mainly used to obtain high yield strength and toughness.

4. High temperature tempering

The hardness after high temperature tempering is generally HB200-330, which is used to obtain better comprehensive mechanical properties.

5. Brinell hardness

The Brinell hardness of 20# seamless steel pipe is ≤156HBS when it is not heat treated.

How to test the hardness of precision tubes?

The test of precision tube hardness usually adopts Rockwell hardness test method, Brinell hardness test method or Vickers hardness test method. Among them, precision tubes with higher refractoriness mostly adopt Rockwell hardness test method; Vickers hardness test method is usually used for testing low hardness steel; Brinell hardness test method is suitable for areas with relatively small product size and relatively high requirements.

Summary

When producing and processing precision tubes, the hardness index should be controlled according to actual needs to ensure the stability and reliability of the hardness of steel tubes. It should be noted that these hardness values are the results under specific heat treatment conditions, and the actual hardness may vary according to the material, heat treatment process and specific use requirements of the steel tube.