| Abstract: | Relationship between fatigue behaviour and non-destructive assessment of weld defects of TIG-welded ultra-high strength steels With respect to the influence of welding defects on the fatigue properties of welded high strength special steels and on the dynamic load carrying capacity of joints in welded constructions, a minimum of information is available. For this reason, the preparation of an assessment standard for classifying weld defects was considered practical, whereby the character of the defects was to be determined using non-destructive testing methods. The investigations were concerned with a special method of producing specimens containing defined and reproducable defects, with the characterization of the defects using X-ray and ultrasonic techniques, and with the determination of the influence of the weld defects on the fatigue strength of TIG-welded joints. As a result of the investigations, a relationship between allowable and critical defect size with respect to an assessment standard has been sought. By introducing weighting factors for various types and sizes of defects occurring in welds the efficiency of non-destructive testing methods for the assessment of weld defects is considerably increased. |
