论文部分内容阅读
对多次补焊下的高速列车用6061-T6铝合金T型接头进行三点弯曲疲劳性能试验,并对疲劳断口做了扫描观察与分析。结果表明:焊接接头指定寿命为1×107次的中值疲劳极限强度随着补焊次数的增加而下降,且补焊次数越多下降幅度越大。疲劳试验中的断裂试件均在焊趾处启裂,裂纹往母材方向延伸,其断口全貌呈纤维状;启裂区和扩展区疲劳纹清晰且较为粗大,但启裂源并不明显;终断区为浅韧窝型韧性断口。
The fatigue test of three-point bending of 6061-T6 aluminum alloy T-type joint for high-speed trains with multiple refinings was carried out, and the fatigue fracture was observed and analyzed. The results show that the ultimate fatigue strength of the welded joints with a specified life of 1 × 107 decreases with the increase of the number of welding repairs, and the more the number of welding passes, the greater the decline. In the fatigue test, all the specimens were cracked at the weld toe, and the crack extended toward the base metal. The fracture surface was fibrous. The fatigue pattern in the crack zone and extension zone was clear and coarse, but the source of cracking was not obvious. Terminal area for the shallow dimpled toughness fracture.