Seamless steel microstructure analysis Structural Testing Laboratory

 Seamless testing, component testing, metallurgical testing, surface roughness: 180--2871--9379 seamless quality inspection methods: 1. Chemical analysis: chemical analysis, instrumental analysis method (infrared C-S instrument, direct reading spectrometer, zcP etc.). ① Infrared C-S instrument: analysis of ferro alloys, steel materials, iron and steel in the C, S elements. ② direct reading spectrometer: bulk sample of C, Si, Mn, P, S, Cr, Mo, Ni, Cn, A1, W, V, Ti, B, Nb, As, Sn, Sb, Pb, Bi ③N-0 instrument: gas content analysis N, O 2. Pipe geometry and appearance inspection: ① pipe wall thickness check: micrometer, ultrasonic thickness gauge, ends not less than 8:00 and recorded. ② pipe diameter, ovality check: calipers, vernier caliper, ring gauge, measure the maximum points and minimum points. ③ pipe length check: steel tape, manual, automatic length measurement. ④ pipe bending degree examination: ruler, level-foot (1m), feeler, thin measuring curvature per meter, length of curvature. ⑤ pipe end face bevel angle and blunt edge inspection: Square, card board. 3. Steel pipe surface quality inspection: 100% ① artificial visual inspection: lighting conditions, criteria, experience, identification, pipe rotation. ② NDT inspection: a ultrasonic testing UT:. More sensitive to a variety of materials uniform surface and internal cracks in the material. Standard: GB / T 5777-1996 levels:. C5 level b eddy current testing ET :( electromagnetic induction) mainly on the spot (hole shape) defect sensitive. Standard: GB / T 7735-2004 level: B c powder MT and magnetic flux leakage detection: magnetic detection, ferromagnetic materials suitable for detecting surface and near-surface defects. Standard: GB / T 12606-1999 Level: C4 level d electromagnetic ultrasonic flaw: No coupling medium, can be applied to high temperature and high speed, roughness of the pipe surface flaw. e penetrant: fluorescence, coloring, testing of steel surface defects. 4. Steel management of performance test: ① Tensile test: measuring stress and deformation, determine the material strength (YS, TS) and plasticity index (A, Z) longitudinal, transverse specimens pipe, curved, circular sample (￠ 10 , ￠ 12.5) small-diameter, thin-walled large-diameter, thick-walled calibration distance. Note: the sample and the sample size of the Elongation related GB / T 1760 ② impact test: CVN, gap C, V-type, power J value J / cm2 standard sample 10 × 10 × 55 (mm) Non-standard test Sample 5 × 10 × 55 (mm) ③ hardness test: Brinell hardness HB, Rockwell hardness HRC, Vickers hardness HV, etc. ④ hydraulic test: the test pressure, the regulator time, p = 2Sδ / D 5. Pipe process performance test: ① flattening test: Sample C round shaped specimens (S / D> 0.15) H = (1 + 2) S / (α + S / D) L = 40 ~ 100mm unit length deformation coefficient = 0.07 ~ 0.08 ② ring pull test: L = 15mm without cracks qualified ③ flaring and crimping test: top center taper of 30 °, 40 °, 60 ° ④ bend test: can replace flattening test (for large diameter pipe terms) 6. Pipe Metallurgical analysis: ① high-power test (microscopic analysis): non-metallic inclusions 100x GB / T 10561 grain size: level, differential tissue: M, B, S, T, P, F, AS decarburization: Inside, A method outside rating:. A category - sulphide Category B - oxides C - D- spherical silicate oxide DS class ② low times test (Macro Analysis): the naked eye, a magnifying glass 10x less etching test method, b. sulfur print test method (test tube, showing low culture organizations and defects such as loose, segregation, subcutaneous bubbles, turn the skin, white spots, inclusions c tower hairline test method: Test hairline number, length and Distribution.