Page 25 - Stanochny park

WELDING TECHNOLOGIES
AND EQUIPMENT
Control methods
Control methods

During the preliminary control of
the main and welding materials, it is
established whether the certificate data
in the documents of the supplying plants
satisfy the requirements for the materials
in accordance with the purpose and
responsibility of the welded assemblies and
structures. Before assembling and welding
the work pieces, it is checked whether their
shape and overall dimensions correspond to
the established ones, and also they control
the quality of preparation of the edges and
surfaces to be welded. In the manufacture
of critical structures, control samples are
welded. Samples for mechanical testing are
cut out of them.. According to the test results, the quality of the main and welding materials, as
well as the qualifications of the welders approved for welding of these structures are evaluated.
During the current control, the compliance by the welders with the established parameters
of the welding modes and the serviceability of the welding equipment are checked. Welds are
inspected to identify external defects and measure their geometric dimensions. The observed
deviations are eliminated directly in the process of manufacturing structures.

Ready welded joints, depending on the purpose and responsibility of the structure, are
subjected to acceptance control:
• external inspection to detect surface defects;
• measurement of welds;
• density tests;
• magnetic control;
• X-ray and gamma-ray transmissions, ultrasound to detect internal defects (Fig. 1)

a b
Fig. 1 Methods of control of welded joints: a - x-ray; b - gamma radiation; c - ultrasonic 1 - x-ray tube; 2 - x-rays; 3 - weld;
4 - cassette with x-ray film; 5 - ampoule with a radioactive isotope; 6 - lead container; 7 - gamma rays; 8 - welded joint; 9 -
x-ray film; 10 - cassette; 11 - welded joint; 12 - piezometric probe; 13 - ultrasonic flaw detector; 14 - oscilloscope

Stanochniy park 25