Day: March 12, 2025

Give you a detailed introduction to the bottom pipe finishing rolling pipe need not heat, the purpose is what, in the square pipe processing process, each stage is indispensable, this process is all the work experience summarized by the ancestors, people must master, below the people will discuss the actual problems at this stage.

The purpose of heating in the heat treatment furnace is:1) Improve the plastic deformation of steel and reduce the deformation resistance. In general, the plastic deformation of steel is weak at ultra-low temperature, and its deformation resistance is great, while the plastic deformation of steel is good at high temperature, and the deformation resistance is small. The mechanism of carbon square tube blank at normal temperature is metallographic structure + cementite. When the finishing rolled pipe is heated, it will change with the increase of temperature. When the steel temperature exceeds the zero boundary point, the internal mechanism of the finishing rolled pipe will change from two-phase mechanism at normal temperature to single-phase electric mechanism ferrite. At this time, the plastic deformation of steel is good, and its deformation resistance is greatly reduced, which is easy to carry out working pressure production and processing.

2) Improve the mechanism characteristics of steel and make its mechanism symmetrical. During the process of ferritization at high temperature, in addition to the change of the metallographic structure of the body-centered cubic meter lattice laser into the ferrite of the body-centered lattice laser, the destruction of the cementite lattice laser is also accompanied by the melting into the ferrite, and the external diffusion of carbon atoms in the ferrite, so that the composition and mechanism of the ferrite are further symmetrical. Within a certain temperature range, the ferrite can be symmetrical and grow, so that the size of the ferrite grain tends to be symmetrical and consistent. In that way, it is not only beneficial to the symmetrical deformation of heat treatment, but also improves the internal organization structure of steel to a certain level. In addition, the prerequisite for the controlled cold rolling of some alloy structural steels is created.

3) It is conducive to cleaning up harmful substances and impurities in steel. When the finishing rolled pipe is heated, the atmosphere in the furnace can be properly controlled, so that the harmful substances in the steel can be cleaned by the diffusion effect of high temperature. Some mixed or strip mechanisms are melted or diffused according to high temperature diffusion, which is convenient for symmetrical dissolution after rolling.

Because of the characteristics of the ground stress conditions of the cross rolled holes, there is a rupture temperature range for a certain alloy structural steel to ensure the quality of the capillary. Therefore, the heating temperature of the finishing rolled tube of alloy structural steel is determined by the hole breaking temperature.

Solid bending
Real bending, as the name suggests, is compacted bending, and the inner and outer rollers and the inner and outer walls of the tube billet are compacted bidirectional during real bending.
1) The advantages of solid bending are small rebound, accurate molding, and as long as the roll shape is accurate, the R of the internal Angle molding is more accurate.
2) The disadvantage of solid bending is that it has a stretching/thinning effect. First, the real bending will cause the bending point to produce tension, tensile effect will shorten the length of the bending line; Second, the metal at the real bend is thinned by stretching.

2. Empty bend

Empty bending is the bending moment formed by the unidirectional contact between the outer roller and the outer wall of the tube blank to bend the strip material. Empty bending will compress the bending line, and the compression effect will cause the bending line to extend longitudinally, and the metal at the bending place will accumulate and become thicker, which is the compression/thickening effect of empty bending.

1) The advantage of empty bending is that side length bending can be performed when solid bending is not possible, such as synchronous bending and finishing of the top/side of the square tube. Air bending can also bend the inner Angle of R<0.2t without breaking the tube wall.

2) The disadvantage of air bending is that when the square rectangular tube is synchronized in the upper/side air bending, the forming force is easy to exceed the critical point due to the pressure generated by the upper roll and the lower roll at the same time, resulting in the instability of the side and the concave, and will also affect the stable operation of the unit and the forming quality. This is also the different characteristics of square tube and round tube air bending.

In practical application, these two basic methods should be configured to a reasonable process position according to the product needs in square tube molding. Attention should be paid to the impact of the stretching/thinning effect of solid bending and the compression/thickening effect of air bending on product quality, otherwise it will cause the side of the square tube to be concave when forming, and the finished tube will be warped longitudewise, and it is difficult to straighten.

Safe installation is the key to ensure the performance of rectangular pipe. To ensure the structural safety of rectangular tubes, it is first necessary to select the appropriate material and type of rectangular tubes. When selecting materials, materials with sufficient strength and corrosion resistance should be selected according to actual needs and the use environment. At the same time, it is also necessary to consider the size and thickness of the rectangular tube to ensure that it can withstand the expected load.
Secondly, when designing the rectangular tube structure, it is necessary to consider its bearing capacity and stability. The design should take into account the force of the rectangular tube, reasonable load distribution, avoid local overload. At the same time, it is also necessary to consider the support and fixing method of the square tube to ensure that it will not be deformed or damaged during use.
In addition, during the construction process, it is necessary to carry out construction in strict accordance with the design requirements to ensure that the installation position, connection and fixing method of the rectangular pipe meet the design requirements. At the same time, it is also necessary to supervise and inspect the construction process to ensure that the construction quality meets the requirements.
Finally, in the process of use, it is necessary to check and maintain the tube regularly to discover and deal with potential problems in a timely manner. At the same time, it is also necessary to pay attention to the use of the rectangular pipe environment to avoid its impact by high temperature, low temperature, corrosive substances, etc., to ensure its structural safety and service life.

In the construction and manufacturing industries, rectangular pipes are popular for their structural stability and load-bearing capacity. However, wet weather poses a challenge for the storage of rectangular tubes, as the humidity can lead to metal rust and corrosion. In order to ensure the long-term performance and service life of rectangular tubes, the following are some practical suggestions for proper storage of rectangular tubes during the wet season.

1. Keep the storage environment dry

Moisture is one of the main causes of metal rust. Therefore, the environment for storing rectangular tubes should be kept dry. If possible, use a dehumidifier or desiccant to reduce air humidity.

2. Avoid direct contact with the ground

The ground is the main source of moisture. Use a packing material, such as wood, plastic or dedicated shelves, to isolate the square tube from the floor and prevent moisture from coming into direct contact with the metal.

3. Use covering for protection

Covering the rectangular tube prevents moisture from directly touching the metal surface. Use a tarp or plastic sheet to cover the rectangular tubes to provide them with an extra layer of protection.

4. Get regular visual exams

In the wet season, regularly check whether the square pipe has signs of rust, and clean it in time. This helps identify problems early and take steps to prevent further corrosion.

5. Cleanliness is key

Before storage, ensure that the surface of the square tube is clean and free of oil. Oil will absorb moisture and accelerate the corrosion process.

6. Properly separate storage

Avoid storing rectangular tubes with other materials that are easy to absorb moisture, such as cardboard, wood, etc., to reduce the accumulation of moisture.

7. Apply rust inhibitor

Apply an anti-rust agent or anti-corrosion coating to the surface of the rectangular pipe to provide additional protection for the metal and delay the rust process.

8. Avoid prolonged outdoor exposure

Try to avoid exposing the square tube outdoors for a long time in wet weather. If you need to work outdoors, choose to do it in dry weather.

9. Choose a suitable storage environment

If conditions permit, store the square tube in an environment with controlled humidity, such as a warehouse or specialized storage room.

10. Ensure proper ventilation

Even indoors, make sure the storage area has proper air circulation to reduce the build-up of moisture.

By following these basic storage guidelines, you can effectively protect your square pipe from the adverse effects of wet weather and maintain its quality and performance. Proper storage methods not only help extend the service life of rectangular tubes, but also ensure their reliability and safety in construction and manufacturing projects.