著者

稲垣 道夫 岡田 明 小林 志希男 木村 勝美 福原 煕明 松本 庄次郎 青木 孝夫 中野 恵司 兼古 光行

出版者

社団法人溶接学会

雑誌

溶接学会誌 (ISSN:00214787)

巻号頁・発行日

vol.51, no.9, pp.775-783, 1982-09-05

被引用文献数

1

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For purpose to obtain the fundamental data of securing the reliability of welded joints, the establishment of welding control technique to make weld defects of arc welded joints in the natural condition, the design and trial making of ultrasonic point focussed probe in order to detect quantitatively planar defects and their application were carried out. And also, effects of the lack of penetration with one side welding of SM50B steels on the fatigue test results of welded joints were investigated. The main results are as follows; (1) Relation between the lack of penetration and welding condition in gas metal arc (GMA) welding were made clear. (2) The point focusing angle probe using spherical tansduser in ultrasonic detecting method was applied to the measurement of the size of lack of penetration. In case that the root face of butt welded joint was gas cut, the detecting accuracy was about±0.5mm. However, in case that there were blow-holes or some weld defects on the way of passing of ultrasonic beam or near the root, the size of planar defect was often mistaken. And also, in case that the root face was closely attached by welding, the detection of lack of penetration was often difficult. (3) The uniaxial stress fatigue strength of arc welded joints for SM50B steels which have the lack of penetration of about 2∿4mm in depth, without reinforcement and finished surface, was extremely lower than that of base metal and welded joints which have full penetration, without reinforcement and finished surface And the fatigue strength of arc welded joints with reinforcement showed the intermediate values between that of base metal or welded joints which have without reinforcement and finished surface and that of welded joint which have the lack of penetration of about 2∿4mm in depth, lowered fairly in comparison with that of base metal. These test results were discussed with non-linear fracture mechanics, consequently, the fatigue limits of welded joints are evaluated with effective notch depth as a whole.