combined defects

Sometimes, defects don´t come alone. Post Destructive examination on Ultrasonic detected indications reveals that combination of defects is not rare. Image below show a slag + lack of fusion. (segments of slag where non intentionally extracted during preparation).

Lack of Fusion Detection

Lack of fusion is one of the most detected discontinuity by UT pulse echo method, conventional or Phased Array mode. Sometimes welders ask that during repair this was not possible to ¨see¨ any discontinuity during grinding or gouging. It is important to take in mind that lack of fusion could be extremely tight and is not possible to detect by non controlled destructive methods.
In the image a extremely small lack of fusion in an austenitic steel weld, that could not be seen without a carefully destructive examination.

Curriculum Vitae

Carlos Correia. Materials Engeeniering Degree (Venezuela Universidad Simón Bolívar  -  1995). Welding Engeeniering Studies (France Institut de Soudure 1998). MASTERS DEGREE PHYSICS OF NON DESTRUCTIVE TESTING (Venezuela – Universidad Central de Venezuela – 2009).

Relevant field experience:

• SMAW welder
• Inspector as level II MT, PT, UT, VT, RT, ET. 
• Extensive use of UT Shear Wave for weld inspection
• Advanced UT Detection using the so called creeping technique
• Advanced Sizing using Tip Diffraction and related methods  
• Extensive use of TOFD for butt weld inspection in pressure vessels
• Manual UT Phased Array Inspection of butt welds
• Encoded UT Phased Array Inspection of butt welds
• UTPA+TOFD
• Corrosion mapping in tank shells using Rexoform
• Corrosion mapping in piping systems using Hydroform and raster scanning.
• Tomoview frequent user.

Research:

• Statistical analysis of UT signals
• DSP of ultrasonic signals and images
• Applying filtering and Neural Networks for Pattern recognition of UT signals
• TOFD Neural network signals simulator
• Failure analysis on welded components
• H₂ high temperature UT damage detection (Backscattering and Velocities change).

Instructor of following training programs:

• Welding Metallurgy (80 hours program)
• Introduction to Phased Arrays
• Advanced Phased Arrays for weld inspection
• TOFD
• PA+TOFD
• Corrosion Mapping (Hydroform Chain Scanner)
• Corrosion Mapping (Rexoform TRIPOD CRAWLER)

Relevant Training received (compilation):

• Welding Metallurgy and Welding Engineering: Institut de Soudure – France
• Phased Arrays Basic and Advanced, TOFD and Tomoview I and II: Eclipse Scientific – Canada
• Transducer construction and modeling with ANSYS – Venezuela
• MT, PT, RT, UT Level I and II – Venezuela
• ANSYS WORKBENCH – Venezuela

Relevant Used Software:

• Omniscan MXU 3.1
• Tomoview 2.10
• UT Win Replay
• Matlab
• Autocad
• Ansys
• Microplus
• Office package

Languages:

• Spanish (1^st)
• English
• French
• Portuguese

Certifications:

• ASNT NDT LEVEL III UT # 176992
• AWS CWI 00110921

Papers at www.ndt.net