Quality inspection method for seamless steel pipe

Seamless steel pipes are widely used in daily life. Let's learn about several basic methods for inspecting seamless steel pipes together.

 

Seamless steel pipes are widely used in daily life. Let's learn about several basic methods for inspecting seamless steel pipes together.

 

1. Inspection of the geometric size and shape of the steel pipe:

 

① Angle and blunt edge inspection of steel pipe end face: corner ruler, stuck plate.

 

② Inspection of steel pipe curvature: ruler, horizontal ruler (1m), plug ruler, thin line measurement of each meter, full length of curvature.

 

③ Steel pipe length inspection: steel tape measure, manual, automatic length measurement.

 

④ Check the outer diameter and ovality of the steel pipe: card gauge, vernier caliper, ring gauge, and measure the maximum point and the minimum point.

 

⑤ Steel pipe wall thickness inspection: micrometer, ultrasonic thickness meter, both ends of not less than 8 points and record.

 

 

2. Chemical composition analysis: chemical analysis method, instrument analysis (infrared C-S instrument, direct reading spectrometer, etc.).

 

① N- -0 instrument: gas content analysis N and O

 

② Direct reading spectrometer: C, Si, Mn, P, S, Cr, Mo, Ni, A1, W, V, Ti, B, Nb, As, Sn, Sb, Pb, Bi in the block sample

 

③ Infrared C-S instrument: analysis of ferroalloy, steel-making raw materials, C, S elements in steel.

 

3. Physical and chemical performance inspection of steel pipe:

 

① Hardness test:

 

Brinell hardness HB, Rockell hardness HRC, Vickers hardness HV, etc Note: The elongation is GB / T 1760 related to the sample size

 

② Impact test:

 

CVN, notch C, V, work J value J / cm²

 

③ Tensile test:

 

measure stress and deformation, determine the strength of the material (YS, TS) and plastic index (A, Z), longitudinal, transverse sample section, arc, circular sample (￠ 10, ￠ 12.5) diameter, thin wall large diameter, thick wall calibration spacing.

 

④ Hydraulic test: test pressure, stabilization time, p=2S δ / D

CREDIT

 

4. Surface quality inspection of steel pipe: 100%

 

① Manual visual inspection:

 

lighting conditions, standards, experience, identification, rotation of steel pipe.

 

② Nondestructive inspection:

 

A. Vortex detection ET: (electromagnetic induction)

 

It is mainly sensitive to the point shape (hole shape) defects. Standard: GB / T 7735-2004 Level: Level B

 

B. Ultrasonic detection UT:

 

For a variety of material uniform material surface and internal crack defects are more sensitive.

 

Standard: GB / T 5777-1996 Level: C5 Level

 

C. Magnetic powder MT and magnetic leakage flaw detection: magnetic force flaw detection, suitable for the detection of surface and near surface defects of ferromagnetic materials.

 

Standard: GB / T 12606-1999 Level: C4 Level

 

D. Electromagnetic ultrasonic flaw detection:

 

No coupling medium is required, and it can be applied to high temperature and high speed, rough and dry steel pipe surface flaw detection.

 

e. liquid penetrating test:

 

Fluorescence, coloring, and detection of steel pipe surface defects.

CREDIT