多频涡流检测连续油管偏焊缝晶粒尺寸的试验研究

Experimental research on grain size of coiled tubing bias welding with multi-frequency eddy current testing

连续油管作业技术在钻修作业中广泛应用,技术核心是连续油管。偏焊缝的质量直接决定疲劳寿命,偏焊缝微观结构与母材是否一致,决定焊缝抗疲劳性能是否达到母材水平。运用多频涡流检测技术,通过检测CT90、CT100连续油管钢带偏焊缝区域与母材区域的电抗来区分母材区域与焊缝区域微观结构及晶粒尺寸是否一致,判断偏焊缝微观组织结构是否达到母材水平。根据其信号特征云图识别焊缝区与母材区,结果表明,连续油管偏焊缝区域与母材相比晶粒尺寸明显变大,并可以看出CT90的焊缝质量好于CT100。根据焊缝区与母材区的微观结构不同对偏焊缝质量进行评价,这对连续油管生产过程质量控制及改进具有指导意义。

Coiled tubing operation technology is widely used in drilling and repair operations,and the core of the technology is coiled tubing.The quality of the bias weld directly determines the fatigue life.Whether the microstructure of the bias weld is consistent with the base material determines whether the fatigue resistance of the weld reaches the level of the base material.This paper uses multi-frequency eddy current testing technology to detect the reactance of the CT90 and CT100 coiled tubing steel strips in the bias weld area and the base material area to distinguish the microstructure and grain size of the base material area and the weld area,and judge whether the microstructure of the bias weld reaches the level of the base material.According to the signal characteristic cloud map,the weld area and the base material area are identified.The results show that the grain size of the coiled tubing bias weld area is significantly larger than that of the base material.It can be seen that the weld quality of CT90 is better than CT100.According to the microstructure difference between the weld area and the base material area,the quality of the bias is evaluated,which has guiding significance for the quality control and improvement of the coiled tubing production process.