1. Chemical composition analysis: chemical analysis method, instrumental analysis method (infrared C-S meter, direct reading spectrometer, zcP, etc.).
① infrared C-S meter: analysis of iron alloys, steelmaking raw materials, steel in the C, S elements.
②Direct reading spectrometer: C, Si, Mn, P, S, Cr, Mo, Ni, Cn, A1, W, V, Ti, B, Nb, As, Sn, Sb, Pb, Bi in block specimen
③ N-0 meter: gas content analysis N, O
2. Steel pipe physical and chemical properties test:
① tensile test: measure stress and deformation, determine the strength of the material (YS, TS) and plasticity indicators (A, Z) longitudinal, transverse specimens pipe sections, arc, round specimens (¢ 10, ¢ 12.5) small calibre, thin-walled large calibre, thick-walled Calibrated distance. Note: the specimen elongation at break with the specimen size GB/T 1760
② impact test: CVN, notch C-type, V-type, work J value J/cm2 standard specimen 10 × 10 × 55 (mm) non-standard specimen 5 × 10 × 55 (mm)
③ hardness test: Brinell hardness HB, Rockwell hardness HRC, Vickers hardness HV, etc.
④ Hydraulic pressure test: test pressure, pressure stabilisation time, p=2Sδ/D
3. Galvanised seamless steel pipe process performance test:
① flattening test: round specimen C-shaped specimen (S / D> 0.15) H = (1 + 2) S / (∝ + S / D) L = 40 ~ 100mm unit length deformation coefficient = 0.07 ~ 0.08
② ring tensile test: L = 15mm no crack is qualified
③ Flaring and crimping test: top centre taper of 30 °, 40 °, 60 °.
Bending test: can replace the flattening test (for large calibre tubes)
