1. Check the surface of the spiral steel pipe to see whether the production process of the spiral steel pipe is exquisite. Generally, it is necessary to study and analyze the spiral steel. The cross-section of the fake and inferior spiral steel pipe is elliptical. The reason is that the manufacturer saves raw materials, and the pressure of the first two rollers of the finished product is slightly larger. The compressive strength of this spiral steel pipe is greatly reduced, and it does not meet the specifications and dimensions of the screw steel products.
High-quality spiral steel pipes have symmetrical components, high cold shear tonnage, and smooth and neat inner holes of the cutting head. However, due to the poor quality of these materials, cutting head holes are often used, which will lead to uneven bumps and no metal texture.
2. Knock on the spiral steel pipe and listen to the sound after knocking. Suppose the sound is crisp and the echo is not chaotic. In that case, it means that this spiral steel pipe is made of new material technology, rather than the comprehensive development and utilization of abandoned spiral steel pipes.
3. The shape detection of the butt weld of spiral steel pipes is a detection mode with simple detection technology and universal application ability. It is an important content of finished product quality inspection. The key is to find out the defects and specification errors on the welding surface of spiral steel pipes. Generally, it is tested based on human visual inspection, relying on special tools such as specification models, instruments, and high-magnifying glasses. If there are defects on the weld surface, there will also be defects inside the weld.

1. If there is dirt on the surface of the product after stainless steel plate processing, it can be wiped with detergent water. However, it should be noted that the material of the product after stainless steel plate processing is mirror or brushed. If it is a mirror, pay special attention to the cleaning tools, and the rag must be clean and dust-free. In addition, there is a special cleaning agent for stainless steel cleaning, called stainless steel cleaning agent or stainless steel brightener, as well as a special care agent and stainless steel oil, which can remove stains and restore the brightness of stainless steel.

2 Tape marks If you want to remove the trademark on stainless steel or the tape marks on the film, you can wipe it with warm water and then wipe it with alcohol.

3 Surface oil stains If there are oil stains and other dirt on the surface of stainless steel, you can directly wipe it with a soft cloth and then clean it with ammonia water.

The main environmental corrosion of colored stainless steel plates is atmospheric corrosion. Atmospheric corrosion in a humid environment, the corrosion rate is mainly controlled by the cathode process. When the water film on the metal surface is very thin or the climate is dry, the corrosion rate of the stainless steel plate slows down, and the corrosion rate is mainly controlled by the anodic polarization process.