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Quality inspection method for seamless steel pipe

2021-12-06 16:38:51   COMMENT:0 HITS:
Seamless steel pipe is widely used in daily life, but many friends do not understand the quality inspection methods of seamless steel pipe.
1. Geometric dimension and appearance inspection of steel pipe:
① Inspection for groove angle and blunt edge of steel pipe end face: angle ruler and chuck.
② Bending inspection of steel pipe: straightedge, level (1m), feeler gauge and fine line to measure the bending per meter and the bending of the whole length.
③ Steel pipe length inspection: steel tape, manual and automatic length measurement.
④ Inspection of outer diameter and ovality of steel pipe: caliper, vernier caliper and ring gauge, and measure the maximum point and minimum point.
⑤ Steel pipe wall thickness inspection: micrometer, ultrasonic thickness gauge, at least 8 points at both ends and record.
2. Chemical composition analysis: chemical analysis method and instrumental analysis method (infrared C-S instrument, direct reading spectrometer, ZCP, etc.).
① N-0 instrument: gas content analysis n, O
② Direct reading spectrometer: C, Si, Mn, P, s, Cr, Mo, Ni, CN, A1, W, V, Ti, B, Nb, as, Sn, Sb, Pb and Bi in block samples
③ Infrared C-S instrument: analyze C and S elements in ferroalloy, steelmaking raw materials and steel.
3. Steel management performance inspection:
① Hardness test: Brinell hardness Hb, Rockwell hardness HRC, Vickers hardness HV, etc
Note: the elongation after fracture of the sample is related to the sample size (GB / T 1760)
② Impact test: CVN, notch C-type, V-type, work J value J / cm2
Standard sample 10 × ten × 55 (mm) non standard sample 5 × ten × 55(mm)
③ Tensile test: measure the stress and deformation, determine the strength (YS, TS) and plasticity index (a, z) of the material, longitudinal and transverse sample pipe sections, arc shape, circular sample (¢ 10, ¢ 12.5) diameter, thin wall, large diameter and thick wall calibration distance.
④ Hydraulic test: test pressure, pressure stabilization time, P = 2S δ/ D
4. Steel pipe surface quality inspection: 100%
① Manual visual inspection: lighting conditions, standards, experience, identification, steel pipe rotation.
② NDT:

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