特殊螺纹油管密封面相控阵超声图像特征分析

Phased Array Ultrasonic Image Characteristic Analysis of Premium Tubing Sealing Surface

特殊螺纹油管密封面的接触状况对密封性能有重要影响。超声反射幅值应力技术仅依靠反射系数单一参数,难以全面评估密封面不同接触状况。为此,通过采集不同扭矩及无螺纹脂情况下油管密封面相控阵超声图像,提取图像的纹理特征,分析纹理特征参数与不同接触状况下的定性及定量关系。研究结果表明:随着油管扭矩的增大,超声图像灰度均值、灰度方差及偏度均减小;油管密封面超声图像灰度共生矩阵对比度,随着油管扭矩的增大,在45°、90°及135°方向上呈线性减小;在0°方向上不含螺纹脂的超声图像是同扭矩下含螺纹脂对比度的2.19倍;油管密封面超声图像灰度共生矩阵熵值,随着油管扭矩的增加,在0°、45°、90°及135°方向上呈线性减小。研究结果可为油管密封面不同接触状况下超声检测图像定性及定量表征提供数据支撑。

The contact condition of the sealing surface of premium tubing has a significant impact on the sealing performance.The different contact conditions of the sealing surface are difficult to be comprehensively evaluated only by the reflection coefficient in the ultrasonic reflection amplitude stress technology.Therefore,in the paper,by means of collecting the phased array ultrasonic images of tubing sealing surface under different torques and without threaded compound as well as extracting the texture features of the images,the qualitative and quantitative relationship between texture feature parameters and different contact conditions was analyzed.The research results show that as the torque of tubing increases,the greyscale mean,greyscale variance and skewness of the ultrasonic image all decrease;the paragenetic matrix contrast of the ultrasonic image greyscale of tubing sealing surface shows a linear decrease in the 45°,90° and 135° directions with the increase of tubing torque;in the 0° direction,the contrast of ultrasonic image without threaded compound is 2.19 times of that with threaded compound at the same torque;the paragenetic matrix entropy value of the ultrasonic image greyscale of tubing sealing surface shows a linear decrease in the 0°,45°,90° and 135° directions with the increase of tubing torque.The research results provide data support for the qualitative and quantitative characterization of ultrasonic detection images of tubing sealing surface under different contact conditions.