由于输送介质具有腐蚀性或介质对管道存在冲刷作用，随着服役期的延长，油气管道的内腐蚀问题日益突出。对其的检测，目前以单点超声检测为主，该方法无法覆盖管道腐蚀区域，易发生漏检且无法准确了解管道的腐蚀状况。对此，对超声C扫描检测技术进行了研究，调研了国内外知名的检测设备，进行了室内试验和现场检测，结果表明：超声C扫描技术具有更高的检测精度和图像分辨率，更高的缺陷检出率和检测效率，为检测点蚀缺陷提供了一种新的检测方法，检测结果能够为管道腐蚀监测、剩余强度评价和剩余寿命预测提供有力的技术支撑。

Because of overtime of service, corrosivity of media and erosion, internal corrosion of oil and gas pipelines has been more and more serious. However, the main way to detect internal corrosion is of single point ultrasonic testing, which cannot cover the whole corrosion region on the pipeline, and we may therefore fail to discover the faults and to learn the status of corrosion of pipelines accurately. According to this, in this paper we have studied the technology of ultrasonic C-Scan by investigating well-known checkout equipments at home and abroad and comparing the results of laboratory experiments with field tests. Finally, we come to a conclusion that the technique of ultrasonic C-Scan has many advantages such as higher detection efficiency, higher detection rate, higher accuracy and higher image resolution. This paper has put forward a new nondestructive testing technology for pitting detection, whose result will provide powerful technological support for corrosion monitoring, residual intensity evaluation and residual life prediction of pipelines.