Derusting method and production process of large-diameter straight seam steel pipe

Introduction of rust removal method for large diameter straight seam steel pipe:
1. Cleaning
Use solvents and emulsions to clean the surface of large-diameter straight seam steel pipes to remove oil, grease, dust, lubricants, and similar organic substances, but it cannot remove rust, oxide skin, welding flux, etc. only as an aid.

2. Tool rust removal
Mainly use tools such as wire brushes to grind the surface of large-diameter straight seam steel pipes, which can remove loose or raised oxide scales, rust, welding slag, etc. The rust removal of hand tools can reach the Sa2 level, and the rust removal of power tools can reach the Sa3 level. If the surface of the large-diameter straight seam steel pipe has firmly adhered to the iron oxide scale, the rust removal effect of the tool is not ideal, and the anchor pattern depth required for anti-corrosion construction cannot be achieved.

3. Pickling
Generally, two methods of chemical and electrolytic pickling are used for pickling, and only chemical pickling is used for pipeline anticorrosion, which can remove oxide scale, rust, and old coating. Although chemical cleaning can achieve the cleanliness and roughness of the surface, its anchor pattern is shallow, and it is easy to cause pollution to the environment.

4. Spray (throwing) rust removal
Spraying (throwing) rust removal is to drive the spraying (throwing) blades to rotate at high speed through a high-power motor, so that abrasives such as steel sand, steel shot, iron wire segments, minerals, etc. are sprayed (throwing) on the surface of the steel pipe under the action of centrifugal force. , not only can rust, oxides and dirt but also large-diameter straight seam steel pipe can achieve the required uniform roughness under the action of abrasive impact and friction.

The production process of large diameter straight seam steel pipe:
The production process of large-diameter straight seam steel pipe generally includes hot rolling, hot-rolling, casting, and other production methods. Generally, the production process of double-sided submerged arc welding is used in the processing of large-diameter thick-walled steel pipe. Welding, straightening, flat head, and other processes meet the petrochemical standard requirements. The use of large-diameter straight seam steel pipes is mainly used for body support parts, such as bridge piling, seabed piling, and high-rise building piling. The materials used for large-diameter straight seam steel pipes are generally Q345B and Q345C. In areas with lower temperatures, Q345D and Q345E large-diameter straight seam steel pipes are also used in large-scale steel structure construction.