Q345/N08825双金属复合板焊接接头冲击韧性分析

Analysis on Impact Toughness of Welded Joint of Q345/N08825 Bimetallic Composite Plate

针对焊接工艺对Q345/N08825双金属复合板焊接接头不同区域力学性能的影响,在-40℃下进行了母材、焊缝和热影响区的低温夏比冲击试验,计算了其对应的断口纤维率;用SEM和EDS进行了断口形貌和夹杂物成分分析,用OM观察分析了焊接接头不同区域的显微组织。结果表明,双金属复合板焊接接头焊缝处冲击吸收功最低,为34.9 J;母材和热影响区不同区域的冲击吸收功相差不大,均高于焊缝,这点通过断口纤维率计算和断口SEM观察得到验证;基材焊缝处存在大量的魏氏组织,是焊缝区域韧性最低的主要原因。

Aiming to the phenomenon that welding processes affecting the mechanical properties of Q345 / N08825 bimetallic composite plate welded joint, Low temperature charpy impact test was carried out on base metal, weld and heat affected zone at-40℃, and then the corresponding fracture fiber percentage was calculated. Scanning electron microscopy（SEM）and energy spectrum analysis（EDS） were used to analyze fracture morphology and inclusions, then the microstructure of different regions of bimetallic welded joint was analyzed through optical microscope（OM）. The results show that the lowest impact energy occurs in weld, which is 34.9 J; the impact energiesin base metal and different regions of HAZ have little difference, and these were verified by fracture fiber percentage and scanning electron microscopy（SEM） fracture observation.The weld of base plate exists a number of widmanstatten structure, which is the reason why the weld has the lowest impact toughness.