LSAW Steel Pipes (straight seam submerged arc welded steel pipes) may encounter various problems during production and use, which may stem from various factors such as materials, processes, environment, or usage methods. The following is a detailed summary of possible problems with LSAW steel pipes:

1. Material issues

Raw material defects:

The center of the billet is loose and segregated, with severe residual shrinkage porosity and excessive non-metallic inclusions.

These defects may lead to problems such as cracks and fractures in the steel pipes during subsequent processing and use.

Welding material issues:

The welding wire and flux do not match, or the quality of the welding material does not meet the standard.

This may lead to unstable weld quality, defects such as lack of fusion and slag inclusion.

2. Process issues

Uneven heating:

Uneven heating of the tube blank, high or low temperature, and long heating time.

This may lead to deformation, cracks, and other issues during the rolling process of steel pipes.

Perforation process issues:

Improper adjustment of perforation machine parameters, aging of perforation rollers, and severe wear of the top end.

This may result in defects such as internal folds and scars on the inner surface of the steel pipe.

Welding process issues:

Improper setting of welding parameters, welding speed too fast or too slow, unstable welding temperature, etc.

This may lead to defects such as incomplete fusion, slag inclusion, and cracks in the weld seam.

Molding process issues:

During the forming process, there is misalignment of the hole pattern and severe wear of the rolling mill rolls.

This may lead to uneven wall thickness and surface wrinkles in the steel pipe.

3. Environmental issues during use

Corrosive environment:

Steel pipes are exposed to corrosive environments for a long time, such as acidic, alkaline, or saltwater environments.

This may lead to corrosion pits, rust spots, and other issues on the surface of the steel pipe.

High temperature and high pressure environment:

The use of steel pipes in high temperature and high pressure environments may lead to a decrease in material properties, resulting in problems such as creep and cracking.

4. Usage issues

Improper installation:

The steel pipe was not installed according to the specifications, such as welding joints not being properly processed and flange connections not being tightened.

This may lead to problems such as leakage and breakage of steel pipes during use.

Improper operation:

Improper handling of steel pipes during use, such as excessive bending, impact, etc.

This may cause problems such as deformation and cracking in the steel pipe.

5. Other issues

Inspection and testing issues:

Steel pipes have not undergone strict inspection and testing during the production process, or the inspection and testing methods are improper.

This may result in the failure to detect defects and issues in the steel pipes in a timely manner.

Transportation and storage issues:

Steel pipes are damaged or contaminated during transportation and storage.

This may cause scratches, rust spots, and other issues on the surface of the steel pipe.

In summary, LSAW steel pipes may encounter various problems during production and use, which may stem from various factors such as materials, processes, environment, or usage methods. In order to ensure the quality and safety of steel pipes, strict control and management are required at all stages of production, inspection, transportation, storage, and use.

In addition to the issues mentioned earlier, LSAW steel pipes (straight seam submerged arc welded steel pipes) may also have the following problems:

1. Weld quality issues

Insufficient weld strength:

The weld seam may have defects such as lack of fusion, slag inclusion, and porosity, resulting in insufficient weld strength.

This may affect the pressure bearing capacity and service life of the steel pipe.

Weld crack:

During the cooling process, the weld seam may develop hot or cold cracks.

The existence of cracks will seriously weaken the strength and sealing of steel pipes.

2. Surface quality issues

Surface scratches:

Steel pipes may be scratched during production, transportation, or installation.

Scratches may affect the appearance and performance of steel pipes.

Surface corrosion:

Long term exposure of steel pipes to humid environments may lead to surface corrosion.

Corrosion will reduce the corrosion resistance and service life of steel pipes.

3. Size and shape issues

Uneven wall thickness:

Uneven wall thickness may occur during the rolling or forming process of steel pipes.

Uneven wall thickness may affect the pressure bearing capacity and service life of steel pipes.

Ellipticity exceeds the standard:

The cross-section of the steel pipe may appear elliptical, and the ellipticity exceeds the standard specifications.

Excessive ellipticity may affect the installation and use of steel pipes.

4. Other potential issues

Hydrogen embrittlement:

Steel pipes may inhale hydrogen gas during welding or heat treatment, leading to hydrogen embrittlement.

Hydrogen embrittlement can reduce the toughness and impact resistance of steel pipes.

Stress corrosion cracking:

Steel pipes may undergo stress corrosion cracking in specific environments such as high temperature, high pressure, and corrosive media.

Stress corrosion cracking is a serious form of failure that can lead to sudden fracture of steel pipes.

In order to avoid the above-mentioned problems with LSAW steel pipes, strict control and management are required at all stages of production, inspection, transportation, storage, and use. At the same time, for problems that have already occurred, timely measures such as repair or replacement should be taken to ensure the quality and safety of the steel pipes.

In addition, the selection and use of LSAW steel pipes should be based on specific application scenarios and requirements, and operated and maintained in accordance with relevant standards and specifications. This helps ensure the reliability and durability of steel pipes, extending their service life.