小径管环向对接接头双壁透照质量的探讨

Discussion on Double Wall Transillumination Quality of Small Diameter Circumferential Butt Joint

就小径管对接焊缝双壁双影椭圆成像上下焊缝开口宽度问题以及小径管双壁双影成像尺寸与所选用焦距大小的关系进行了探讨。椭圆成像时,控制上焊缝射线束的投影方向与焊缝截面的夹角大小,有助于射线源侧焊缝根部未焊透和根部纵向裂纹的检出;通过测量双壁双影成像后外径尺寸间接得知现场实际透照时焦距大小,从而判断现场透照焦距是否满足标准要求。

In this paper,the problem of the upper and lower weld opening width of the double wall double shadow elliptical imaging of the butt weld of the small diameter pipe and the relationship between the double wall double shadow imaging size of the small diameter pipe and the selected focal length are discussed.It is concluded that during the elliptical imaging,controlling the included angle between the projection direction of the upper weld beam and the weld section is helpful to detect the root incomplete penetration and the root longitudinal crack at the ray source side.By measuring the outer diameter of double wall and double shadow imaging,we can indirectly know the focal length of on-site actual transillumination,so as to judge whether the on-site transillumination focal length meets the standard requirements.