TOFD indication

  • Posted by george on 27/11/2021 at 5:26 pm

    Dear Colleagues,
    Question is about characterization of TOFD indication.
    Scan made by: 10 Mhz, ø 6 mm, angle 70°, 62 mm PCS, Olympus probes / wedges, someteimes LW is too high

    Weld details are:
    17 mm thick, X bevel, 16Mo3, girth weld on heat exchanger
    Exploitation conditions:
    350°C opertional temp, 40 bar presaure, 1976 year of production, (below Nelson Curve)
    I am not sure of my diagnosis (root corrosion? LOF?) I am wonder Yours opinion.
    I made this place also by PA (32 elements, 5Mhz, compound scan, 17 mm indeks offset),
    below some print screens.

    charlie replied 7 months, 1 week ago 2 Members · 1 Reply
  • 1 Reply
  • Time of Flight Diffraction (ToFD)


    28/11/2021 at 2:32 pm
    2 Points

    the indications look like production defect. usually corrosion defects that detected by TOFD will affect on back wall position and amplitude of back wall signal(if it is big pitting).index position of corrosion on S-Scan will be different from each side and you can measure the width of corrosion by PAUT.

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0 of 0 replies June 2018