炉管作为石油化工企业中大型管式燃料加热炉的重要组成部件，不仅投资费用高，且是失效频率最高的部件，因此如何采用有效的检测技术来测试炉管的氧化程度显得尤为重要。运用磁性检测技术和声发射检测技术，针对已服役50 000 h的规格为φ114 mm×6.5 mm（外径×壁厚）的炉管，分别对其向火面、背火面及过渡面进行磁性测试和声发射衰减测试，通过对比不同氧化程度的矫顽力大小及声信号衰减状况，来分析磁性检测技术与声发射检测技术在炉管氧化层厚度检测中的有效性。结果表明，磁性检测技术与声发射检测技术均可应用于炉管氧化程度的检测，矫顽力的大小取决于炉管的氧化程度及氧化层的附着程度，而声信号衰减梯度变化对氧化层厚度较敏感，氧化层的厚度越厚其声信号衰减梯度越大。

Furnace tube as an important component of large tube type fuel heating furnace used in petroleum chemical industry not only is of the high cost of investment accounting, but also is of the highest frequency component failure. Therefore, the adoption of effective detection techniques to test tube oxidation degree is very important. This paper uses acoustic emission detection technology and magnetic detection technology to test magnetic signal and acoustic signal of the fire surface, back surface and transition surface about the tube of φ114 mm×6.5 mm (outer diameter×wall thickness) and has been on active service for 50000 hours. Through comparison of different results of testing under various oxidation degrees, the detection effectiveness of magnetic detection technology and acoustic emission detection technology was investigated. Results show that, the magnetic detection technology and acoustic emission detection technology can be used in furnace tube oxidation degree detection. The coercive force depends on the size of the furnace tube degree of oxidation and the degree of adhesion of oxidation layer, and acoustic signal attenuation gradient is more sensitive to the change of the oxide layer thickness, and the thicker the thickness of the oxide layer, the greater the acoustic attenuation gradient is.