摘要
为了研究高速列车常用A6005A铝合金材料抵抗裂纹扩展能力,对其焊接接头断裂韧性和冲击韧性进行了求解.采用三点弯曲法、扫描电子显微镜等求出焊接接头各部位冲击韧性、断裂韧性以及断口形貌,得到断裂韧性CTOD值δm(8)和J积分值Jm(8).试验结果表明,热影响区的冲击功为16.3 J;母材冲击功为11.5 J;焊缝区域最差,冲击功为5.5 J.CTOD数据表明,HAZ处δm(8)=0.373 9 mm,母材δm(8)=0.089 2 mm,焊缝δm(8)=0.069 7 mm.J积分数据表明,HAZ处Jm(8)=109.454 kJ/m2,母材Jm(8)=38.249 kJ/m2,焊缝Jm(8)=16.231 kJ/m2.热影响区断口上韧窝比母材上韧窝大,其韧性更好.焊缝上气孔、夹杂较多,其塑性较差,冲击吸收功很低.冲击韧性和断裂韧性表征规律一样,热影响区值抵抗裂纹扩展能力最好,母材次之,焊缝区最差.
To investigate the crack propagation of welded joints of A6005A aluminum alloy used in high speed train,a preliminary test is made to determine the fracture toughness and impact toughness.Three point belt and SEM has been used to test the fracture toughness CTOD δm（8）and Jm（8）of different regions of the welded joints.The results showed that the value of impact energy of HAZ was 16.3 J,the matrix was 11.5 J,and the weld was only 5.5 J.The δm（8） of HAZ was 0.373 9 mm,the matrix was 0.089 2 mm and the weld was 0.069 7 mm.The Jm（8） of HAZ was 109.454 kJ/m2,the matrix was 38.249 kJ/m2,and the weld was 16.231 kJ/m2..The dimples on the fracture surface of HAZ were larger than that on the matrix,which showed good toughness.The weld showed bad toughness and low impact energy because of the porosity and inclusions.The impact toughness and fracture toughness indicated the same rule that the HAZ zone had the best property in crack propagation,followed by the matrix and the weld.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2013年第2期55-60,共6页
Materials Science and Technology
基金
国家科技支撑计划资助项目(2009BAG12A04-D02)
