アルミニウム合金の溶接熱影響部における微小割れについて

概要

論文の詳細を見る
In this study, micro-fissuring in heat-affected-zone of aluminum alloy welds was investigated. Test panels were 4,6 and 12mm thick plates of Al, Al-Cu, Al-Mg, Al-Mg-Si, Al-Zn-Mg-Cu and Al-Zn-Mg alloys. Micro-fissuring was detected by the dye-penetrant test and the observation of micro-structures of cross-section. The results were as follows. (1) Micro-fissuring in heat-affected-zone appeared to be lamellar tears, and it was the grain-boundary cracking showing a semi-continuous shape. (2) Micro-fissuring was observed remarkably in Al-Cu and Al-Zn-Mg-Cu alloys, and followed by Al-Zn-Mg and Al-Mg alloys. It was scarcely observed in Al-Mg-Si alloy and a commercially pure aluminum except for special cases. (3) The external factors affecting micro-fissuring in heat-affected-zone were considered to be plate thickness, welding conditions and procedures, pass number and so on. The degree of micro-fissuring increased with the heat input per unit thickness of plate. (4) On the other hand, the inherent factors were condisered tobe the thermal stress produced by thermal expansion and shrinkage and the partial melting of eutectic compositions in grain boundaries. (5) It was concluded that the sequence and mechanism of lamellar tearing in heat-affected-zone were similar to those of the gene4ral soridification cracking.
社団法人溶接学会の論文
1971-09-25