摘要
加强筋宽度为3 mm的含型腔扩散焊零件会因焊缝区域出现微小气孔、夹杂等缺陷而导致失效,但由于含型腔坯料的厚度为40 mm,加强筋宽度仅为3 mm,检测声波难以有效到达加强筋位置,且加强筋结构处存在复杂声反射结构波,造成加强筋内部焊缝缺陷难以有效检出。利用ϕ0.4 mm的平底孔模拟气孔缺陷,采用相控阵扇扫成像技术对3 mm宽度的加强筋焊缝处平底孔缺陷进行扫查。根据扇形扫描相位分布特点,提出一种相位相干的加权方法,通过加权处理抑制加强筋复杂反射造成的非缺陷结构波干扰。结果表明:当探头主声轴方向与焊缝平行且探头偏离缺陷正上方,即缺陷偏离扇扫图像中心19°时,可以将缺陷与非缺陷结构波分隔开;但探头偏离缺陷正上方的程度越大,缺陷幅值越低。相位相干处理后,非缺陷回波得到抑制,缺陷仅偏离扇扫图像中心13°即可。与原始扇扫图像相比,偏转角度变小,缺陷的成像质量提升。
Diffusion welding parts with cavities and a stiffener width of 3mm will fail due to defects such as small holes and inclusions in the welding area.However,the thickness of the blank containing the cavity is 40 mm,and the width of the stiffeners is only 3 mm,making it hard for sound waves to reach the stiffeners in ultrasonic testing process.Additionally,complex acoustic reflection structural waves at the stiffeners make it hard to effective detect the internal weld defects in the stiffeners.To address the above difficulties,this work uses a flat bottom hole with a diameter of 0.4 mm to simulate porosity defects,and phased array sector scanning imaging technology to detect the flat bottom hole defects at the 3 mm wide reinforcing rib weld seam.According to the phase distribution characteristics of sector scanning,a phase coherence weighting method is proposed to suppress the non-defective structural echo caused by the complex reflection of stiffener.The results show that the defect can be separated from the non-defective structural wave when the main acoustic axis direction of the probe is parallel to the weld seam and the probe deviates directly above the defect,i.e.the defect deviating by 19°from the center of the sector scan image.However,the greater the deviation of the probe from the defect top,the lower the defect amplitude.After phase coherence processing,non-defective echoes are suppressed,and defects can only deviate by 13°from the center of fan scan image.Compared with the original sector scan image,the deflection angle decreases and the imaging quality of defects is improved.
作者
孔庆茹
陈尧
马啸啸
陈明
KONG Qing-ru;CHEN Yao;MA Xiao-xiao;CHEN Ming(Key Laboratory of Nondestructive Testing(Ministry of Education),Nanchang Hangkong University,Nanchang 330063,China)
出处
《失效分析与预防》
2023年第6期362-368,399,共8页
Failure Analysis and Prevention
基金
国家自然科学基金(62161028,12064001,51705232)
南昌航空大学研究生创新基金(YC2021061,YC2022-093)。
关键词
加强筋
扩散焊
相位相干
相控阵
超声检测
stiffener
diffusion welding
phase coherent
phased array
ultrasonic testing