Non-Destructive Testing of Heated Tool Butt Welded Pipes Using Optical Methods

Ultrasonic and radiographic methods were used up to now to locate discontinuities in materials. The author shows that it is also possible to determine other factors which have an adverse effect on quality. A num- ber of conditions are discussed which exert an influence on the strain of materials It is shown that the strain behaviour of welded joints is a feature suitable to describe the quality of such joints. Methods used for determining strain and the quality assessments archie- ved by such methods are described. The results show that high-quality welded joints exhibit minor local strain in the weld.