1. Steel pipe geometry and shape inspection:
① Inspection of the bevel angle and blunt edge of the steel pipe end face: square, pallet.
②Steel tube curvature inspection: straightedge, level (1m), feeler gauge, thin wire to measure the curvature per meter, and the full-length curvature.
③ Steel pipe length inspection: steel tape measure, manual and automatic length measurement.
④ Check the outer diameter and ovality of the steel pipe: caliper, vernier caliper, ring gauge, and measure the maximum and minimum points.
⑤ Inspection of steel pipe wall thickness: micrometer, ultrasonic thickness gauge, no less than 8 points at both ends and record.
2. Chemical composition analysis: chemical analysis method, instrumental analysis method (infrared C—S instrument, direct reading spectrometer, zcP, etc.).
①N-0 instrument: gas content analysis N, O
②Direct reading spectrometer: C, Si, Mn, P, S, Cr, Mo, Ni, Cn, Al, W, V, Ti, B, Nb, As, Sn, Sb, Pb, Bi in the bulk sample
③Infrared C-S instrument: Analyze C and S elements in ferroalloys, steelmaking raw materials, and steel.
3. Steel management performance inspection:
①Hardness test: Brinell hardness HB, Rockwell hardness HRC, Vickers hardness HV, etc.
Note: The elongation of the sample after breaking is related to the size of the sample GB/T 1760
②Impact test: CVN, notched C type, V type, work J value J/cm2
Standard sample 10×10×55 (mm) Non-standard sample 5×10×55 (mm)
③Tensile test: measure the stress and deformation, determine the strength (YS, TS) and plasticity index (A, Z) of the material, longitudinal and transverse specimen tube sections, arc, circular specimen (￠10, ￠12.5) diameter, Thin-walled large-diameter, thick-walled calibration distance.
④Hydraulic test: test pressure, voltage stabilization time, p=2Sδ/D
4. Steel pipe surface quality inspection: 100%
①Artificial visual inspection: lighting conditions, standards, experience, signs, steel pipe rotation.
②Non-destructive inspection:
a. Eddy current flaw detection ET: (electromagnetic induction)
Mainly sensitive to point (hole-shaped) defects. Standard: GB/T 7735-2004 Level: Class B
b. Ultrasonic flaw detection UT:
It is more sensitive to the surface and internal crack defects of various materials with uniform materials.
Standard: GB/T 5777-1996 Level: C5
c. Magnetic powder MT and magnetic flux leakage inspection: Magnetic inspection is suitable for the detection of surface and near-surface defects of ferromagnetic materials.
Standard: GB/T 12606-1999 Level: C4
d. Electromagnetic ultrasonic flaw detection:
No coupling medium is required, and it can be used for high-temperature, high-speed, and rough surface inspection of steel pipes.
e. Penetration inspection:
Fluorescence, coloring, and detection of surface defects of steel pipes.
Post time: Nov-02-2023