The testing method for LSAW Steel Pipes (straight seam submerged arc welded steel pipes) is a comprehensive process aimed at ensuring that the quality and performance of the steel pipes meet the design requirements. Here are some key detection methods:

1. Appearance inspection

Visual inspection:

Inspect the surface of the steel pipe with the naked eye or a low-power magnifying glass to detect defects such as cracks, slag inclusions, folds, heavy scales, and oxide scales.

Dimensional measurement:

Use tools such as rulers, tape measures, and vernier calipers to measure the diameter, wall thickness, length, ovality, curvature, and other geometric dimensions of steel pipes.

2. Non destructive testing

Magnetic particle testing:

Suitable for surface and near surface defect detection of ferromagnetic steel pipes.

Using magnetic field to magnetize steel pipes, leakage magnetic flux is generated at the defect location, and the defect is displayed through magnetic powder.

Penetration testing:

Suitable for surface defect detection of ferromagnetic and non ferromagnetic steel pipes.

Use a penetrant liquid (such as fluorescent dye) to penetrate the surface of the steel pipe and display defects through a display agent.

Radiographic testing:

Use X-rays or gamma rays to irradiate steel pipe welds, and detect defects in the welds by detecting the attenuation of the transmitted radiation.

Radiographic testing can be used to inspect defects such as cracks, incomplete penetration, porosity, and slag inclusions in welds.

Ultrasonic testing:

Use ultrasonic waves to propagate in steel pipes and detect internal defects through reflection and scattering.

Ultrasonic testing can more sensitively locate defect locations, but determining the nature, shape, and size of defects may be difficult.

Jet (water column) ultrasonic testing is a special form of ultrasonic testing that improves the accuracy of detection by coupling a jet between the probe and the steel pipe.

3. Mechanical performance test

Tensile test:

Test the tensile strength and yield strength of steel pipes.

Impact test:

Test the impact toughness of steel pipes.

Hardness test:

Test the hardness value of steel pipes and evaluate their wear resistance and deformation resistance.

4. Chemical composition analysis

Spectral analysis method:

Analyze the element content in steel pipes using methods such as atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS), and X-ray fluorescence spectroscopy (XRF).

Chemical analysis method:

Including wet analysis and dry analysis, quantitative analysis of specific elements is achieved through steps such as sample dissolution, precipitation separation, and titration determination.

5. Other tests

Hydrostatic test:

Conduct water pressure testing on steel pipes to check their pressure bearing capacity and sealing performance.

Metallographic analysis:

Observe the metallographic structure of steel pipes through a microscope to evaluate their microstructure and properties.

In summary, the testing methods for LSAW steel pipes involve multiple aspects such as visual inspection, non-destructive testing, mechanical property testing, chemical composition analysis, and other specialized testing. These methods together constitute a complete system for LSAW steel pipe quality inspection, ensuring that the quality and performance of the steel pipe meet the design requirements and usage needs.