304 SS seamless stainless steel capillary tubes

304 SS seamless stainless steel capillary tubes is a widely used key with high hardness and high corrosion resistance, and is widely used in many fields. Among them, its hardness can be divided into three types: Brinell hardness, Rockwell hardness and Vickers hardness, with different use characteristics. During production, it has undergone a certain manufacturing process to make the pipe fittings more in line with production requirements. So do you know the hardness of stainless steel seamless pipes, what is the production process, and what are the differences between them and seamed pipes? Take a look at the explanation below and you will know!

How hard are 304 SS seamless stainless steel capillary tubes?

1. Brinell hardness: In the steel pipe rust prevention standard, Brinell hardness is widely used, and the indentation diameter is often used to represent the hardness of the material, which is both intuitive and convenient. But it is not suitable for harder or thinner steel pipes.

2. Rockwell hardness: The Rockwell hardness test of stainless steel pipes is the same as the Brinell hardness test, which is an indentation test method. The difference is that it is used to measure depth. At present, the Rockwell hardness test method is widely used, and the standard hardness of HRC is slightly lower than that of Brinell hardness.

3. Vickers hardness: At the same time, the Vickers hardness test of stainless steel pipe is also a method of measuring indentation. Its main feature is the combination of the Brinell method and the Rockwell method, which overcomes its basic shortcomings, but the method is simpler than the Rockwell method. , which is less used in steel pipe standards.

What is the manufacturing process of 304 SS seamless stainless steel capillary tubes?

1. Generally, the automatic tube rolling unit produces hot-rolled stainless steel seamless tubes, inspects the solid tube blanks and removes surface defects, cuts off the tube blanks of the required length, centers the perforated end faces of the tube blanks, and then sends them to the heating furnace for heating. Perforation is carried out in the punching machine. Under the action of the roller and the plug, a cavity is gradually formed inside the tube blank, which is called a capillary.

2. In order to obtain seamless pipes with smaller size and better quality, cold rolling method, cold drawing method or a combination of the two methods can be used. The cold continuous rolling mill generally adopts a two-roll continuous rolling mill. Usually 0.5~100T cold drawing is carried out on the cold drawing machine, mainly for single or double chains.

3. The extrusion method puts the heated tube blank into a sealed extrusion cylinder, and the extrusion part is extruded from the smaller die hole due to the movement of the perforated rod and the extrusion rod. Smaller diameter pipes can be produced in this way.

What is the difference between 304 SS seamless stainless steel capillary tubes and seamed tubes?

1. Differences in production process: Stainless steel welded pipe: It is formed by rolling a steel plate or a steel strip through a unit and a die. Welded pipes are divided into straight seam welded pipes and spiral welded pipes, which are more common.

2. Appearance: stainless steel welded pipe: uniform wall thickness, high brightness on the inner surface of the pipe (determined by the surface grade of the steel plate), can be arbitrarily determined, and thin-walled pipes can be made. Seamless steel pipe: uneven wall thickness, low brightness on the inner surface of the pipe, high cost of fixed-length, pitting on the inner and outer surfaces, black spots are not easy to remove, and the pipe wall is often thick.

3. Performance: The corrosion resistance and pressure and high temperature resistance of the seamless pipe are better than those of the stainless steel welded pipe. Due to the improvement of the production process of stainless steel welded pipes, its mechanical properties and mechanical properties are gradually approaching seamless pipes, which can replace seamless pipes to some extent.

4. Price: The production process of 304 SS seamless stainless steel capillary tubes is more complicated, and its price is also more expensive than welded tubes.