【作者】 刘辉；

【导师】 康宜华； 武新军；

【作者基本信息】 华中科技大学 ， 测试计量技术及仪器， 2008， 硕士

【摘要】 随着我国石油化工产业和基础建设工程的迅猛发展,钢管需求飞速增长,生产效率要求越来越高,高速和超高速的钢管漏磁无损检测设备需求迫切。但目前漏磁检测设备在检测纵向伤时多采用钢管螺旋运动或扫描装置旋转运动,钢管高速漏磁检测的实现受到制约,本学位论文提出一种基于直流正交磁化的漏磁检测方法,该方法不需要钢管或检测设备高速旋转,可实现钢管纵向伤的高速检测,具有检测全面、快速、可靠等优点,克服了高精度、高旋转主轴和滑环系统制造的困难。论文通过多种检测探头和多种扫描方式的对比实验,结果表明贴片电感作为磁敏检测元件适用于该检测方法。利用贴片电感探头对钢管25mm(长)×1mm(宽)×0.5mm(深)的纵向伤进行检测实验,检测信号良好,并确定了单对磁化器的周向有效磁化范围为240°和单个检测元件的周向有效检测范围为20°。针对管道纵向伤检测的影响因素,并根据实验结果,设计了基于直流正交磁化的钢管漏磁检测装置,包括由两个单元组成的直流正交磁化器,适用于多规格的钢管并能自动对中的探头装置,探靴内部检测元件的布置方式,信号放大电路及后处理系统。利用该检测装置对标样纵向伤的检测实验表明,该钢管纵向伤漏磁检测装置可检测出25mm(长)×1mm(宽)×0.3mm(深),检测灵敏度高,由于不需要旋转运动,降低了机械系统的复杂性,稳定性好,具有广泛应用前景。更多还原

【Abstract】 As the rapid development of oil chemical industry and basic contribution project in China, the need of steel pipes is growing at very fast speed, and the requirement of the production efficiency is higher and higher. It takes urgent requirement of high-speed and over-high-speed magnetic flux leakage non-destructive testing for steel pipes. Steel pipe spiral movement or devices rotating scanning was used to detected defects by the magnetic flux leakage equipment, thus high-speed magnetic flux leakage testing of steel pipe was constrained. A new magnetic flux leakage method based on the DC orthogonal magnetization was developed in this dissertation. This method does not need to revolve the steel pipe or equipment, may realize high speed detection of longitudinal flaws of steel pipe. The method was of fast, reliable, has overcome the manufacture difficulty of high accuracy, the high kingbolt and the link system.The dissertation has contrasted on many experiments by many kinds of probe and scanning way. The result indicates the piece inductance is suitable as magnetism sensitive detecting element for this examination method. The longitudinal flaw of steel pipe, 25mm(length)×1mm(wide)×0.5mm(depth), can be detected, and magnetizer’s circumferential effective magnetization scope for 240°and the single detecting element’s circumferential effective detection range for 20°has determined.According to the influence factors of longitudinal flaws detection of pipes and the experimental results, the author designs the equipment of Magnetic Flux Leakage Testing for longitudinal cracks of steel pipes. The equipment includes the orthogonal magnetization equipment by direct current, the probe, the signal amplification circuit and post-processing system. The orthogonal magnetization equipment is made up with two magnetization unit. The probe, which is applied to multi-specification pipes, can be centered automatically and keep following favorably. And the collocation mode of the probe inside detecting elements is designed.The longitudinal flaw of the steel pipe, 25mm(length)×1mm(width)×0.3mm(depth), can be detected with the equipment. The result indicates that this equipment has high detecting sensitivity and good stability, and is provided with great abroad application foreground.更多还原