First, the physical and chemical properties of high-frequency welded steel pipes.
Room temperature mechanical properties, high temperature mechanical properties, low temperature properties, and corrosion resistance. The physical and chemical properties of high-frequency welded steel pipes mainly depend on the chemical composition, microstructure, purity of the steel, and heat treatment methods.
(1) Process performance of high-frequency welded steel pipes: Flattening, flaring, edge rolling, bending, welding, etc.
(2) Metallographic structure of high-frequency welded steel pipes: Low magnification (macro), high magnification (micro) M, B, P, F, A, S
(3) Special requirements for high-frequency welded steel pipes: Contract appendices, technical agreements.
Second, inspection methods for high-frequency welded steel pipes:
1. Chemical composition analysis: Chemical analysis method, instrumental analysis method (infrared C-S spectrometer, direct-reading spectrometer, ZCP, etc.).
(1) Infrared C-S spectrometer: Analyzes ferroalloys, steelmaking raw materials, and C and S elements in steel. (2) Direct-reading spectrometer: Analyzes C, Si, Mn, P, S, Cr, Mo, Ni, Cn, Al, W, V, Ti, B, Nb, As, Sn, Sb, Pb, and Bi in block samples.
(3) N-O analyzer: Analyzes the gas content of N and O.
2. Geometric dimensions and shape inspection of high-frequency welded steel pipes:
(1) Wall thickness inspection of high-frequency welded steel pipes: Micrometer, thickness gauge, at least 8 points at both ends, and record the readings.
(2) Outer diameter and ovality inspection of high-frequency welded steel pipes: Caliper gauge, vernier caliper, ring gauge, measure the large and small points.
(3) Length inspection of high-frequency welded steel pipes: Steel tape measure, manual, and automatic length measurement.
(4) Curvature inspection of high-frequency welded steel pipes: Ruler, level (1m), feeler gauge, fine string to measure curvature per meter, and total curvature.
(5) Bevel angle and blunt edge inspection of high-frequency welded steel pipe end faces: Square, caliper.
Third, surface inspection of high-frequency welded steel pipes: 100%
(1) Manual visual inspection: lighting conditions, standards, experience, markings, and rotation of the high-frequency welded steel pipe.
(2) Non-destructive testing: lighting conditions, standards, experience, markings, and rotation of the high-frequency welded steel pipe.
(3) Ultrasonic testing (UT): highly sensitive to surface and internal crack defects in materials of various uniform types.
Post time: Dec-11-2025