When some users purchase 304 stainless steel pipes, they often judge the quality of 304 stainless steel pipe according to the hardness and softness. This approach is neither right nor wrong. It is impossible to judge the quality simply by the hardness of 304 stainless steel pipe. Today, Huashang Steel will give you an analysis: what is the hardness of stainless steel pipe, and what's the difference?
Common index to measure the hardness of stainless steel pipe are the following three: Brinell, Rockwell and Vickers.
The differences are as follows:
1. Vickers hardness (code HV)
Vickers hardness test of stainless steel pipe is a kind of indentation test method, which can be used to measure the hardness of very thin metal materials and surface layers. It has the main advantages of Brinell and Rockwell test methods, but it overcomes their basic disadvantages, and it is not as simple as Rockwell method, and the Vickers method is rarely used in the steel pipe standard. However, Vickers hardness test has a wide measurement range, which can measure almost all the metal materials used in the industry at present.
2. Brinell hardness (code HB)
In the stainless steel pipe standard, Brinell hardness is the most widely used, and the indentation diameter is often used to express the hardness of the material, which is both intuitive and convenient. However, it is not suitable for hard or thin steel and steel pipes.
3. Rockwell hardness (code HR)
Like the Brinell hardness test, it is indentation test method. But it measures the depth of the indentation. Rockwell hardness test is a widely used method at present, but there are three standards of Rockwell hardness: scale a, B and C, which are usually recorded as HRA, HRB and HRC. The expression method is hardness data plus hardness symbol, such as 50HRC. Among them, HRC is second only to Brinell hardness Hb in steel pipe standard. Rockwell hardness can be used to measure metal materials from very soft to very hard, and the hardness value can be read directly from the dial of hardness machine. But the hardness value is not as accurate as Brinell method. When the tested sample is too small or the Brinell hardness (HB) is greater than 450, use Rockwell hardness measurement instead.
We usually use two kinds of stainless steel decorative pipe materials: 201 stainless steel pipe and 304 stainless steel pipe
. The main factor affecting the hardness of the two is the carbon content in the raw material. The carbon element mainly improves the hardness in the stainless steel pipe, but it is not that the higher the hardness is, the better the carbon content is, the lower the plasticity of the stainless steel pipe is, and the easier it is to rust. Another factor that affects the hardness of 201 stainless steel pipe is the content of copper element in it. The 201 stainless steel pipe with high copper content has better toughness, better plasticity and softer pipe.
Therefore, it's not accurate to judge the quality of stainless steel pipe simply by the hardness and softness of 304 stainless steel pipe or 201 stainless steel pipe. Huashang Steel
recommends that you choose the stainless steel pipe manufacturer
with guaranteed quality when purchasing.