熱間せん断法による鉄筋ガス圧接部の品質評価とその信頼性

鋼ガス圧接部ふくらみ熱間せん断による非破壊検査(第4報)

抄録

The previous reports have clarified that the quality of gas pressure welds is influenced by local area expansion factor (α) and weld temperature (T) ; hot shearing method helps evaluate the quality of welds ; and that a line flaw, if bonding work is poor, is caused by tensile stress which occurs at shearing edge.
In this paper, a study about the influence of bulge removal on weld's strength, and the reliability of quality estimation by hot shearing method of steel bar gas pressure welds is reported. The conclusions are as follows :
(1) The quality of gas pressure welds scarcely declines by hot shearing.
(2) Whether hot shearing is applied or not, the influence of various factors, such as welding process, surface condition, and gap between surfaces, on weld's strength is constant.
(3) In bending test, the acceptable rate of welds submitted to hot shearing is lower than that of welds without hot shearing.
(4) The fatigue strength of welds is scarcely influenced by hot shearing.
(5) The reliability of hot shearing method is higher than that of penetrant method or ultrasonic method.