Stainless steel pipe has good corrosion resistance and high temperature resistance. It is often used in chemical industry, food industry, mechanical instrument and other industrial transportation pipes and mechanical structure components. Do you know how stainless steel pipelines are produced? Here's how it works.

1、Material selection

BA grade cold-rolled stainless steel strip is used as raw material. Check the raw material chemical component, thickness, width, edge state, appearance and physical performance test before entering the factory for using. Ensure the quality of raw material.

2、Uncoiling

Before welding, it is necessary to use the uncoiling machine to peel the steel belt and make the roll seam flat.

3、Automatic welding

TIG welding equipment is used for continuous welding. Use argon gas protection inside and outside to ensure the welded seam silver white and prevent the heat color and poor chromium area.

4、Deoil

Clean inside and outside.

5、 Annealing

In the process of roll bending, the steel belt will produce work hardening, which is not conducive to the later processing of the pipe, especially the bending process. In the welding process, there will be welding stress at the weld seam, which will cause potential cracking in the later process, so it requires heat treatment.

At present, heat treatment process is bright solid solution treatment under hydrogen protective atmosphere. Single austenitic stainless steel structure was obtained by fully hydrogen annealing at 1040-1100 ℃ to eliminate stress and weld sensitization area.

6、Eddy current inspection

It is difficult to detect internal defects of welds only by pressure detection. Online eddy current detection and ultrasonic detection can be used for 100% real-time online detection. According to the alarm information, the welding state can be corrected at any time to reduce unqualified products.

7、Sizing cutting

According to the length required by customers, make fixed size cutting by online fixed size cutting equipment.

8、straightening

The straightness of welded pipe produced by roll bending molding unit can not meet requirements. Generally, the straightness of such welded pipe should be controlled at 0.10/100mm. It is necessary to use straightening machine to straighten the welded pipe to meet the requirements.

9、Airtight detection

Do pressure test for stainless steel pipe by automatic static hydraulic testing machine and separate unqualified welded pipe.

10、Surface treatment

The pickling eliminates the oxidation component produced during processing and forms the stainless steel passivation film. And polishing can ensure a good appearance.

11、Clean and dry

After mechanical processing, the welded pipe needs to be cleaned and dried to remove the coolant, oil and other pollutants remaining on the inner wall or outer wall of the pipe, and then dried with hot air to prevent rust during transportation and storage. Finally the stainless steel welded pipe do finished product inspection and packaging.