方管表面缺陷的檢測(cè)方法，主要有以下五種：一電渦流檢測(cè).電渦流檢測(cè)有多種形式，常用的有常規(guī)渦流檢測(cè)、遠(yuǎn)場(chǎng)渦流檢測(cè)、多頻渦流檢測(cè)和脈沖渦流檢測(cè)等，利用電渦流傳感器對(duì)金屬進(jìn)行感應(yīng)，方管表面不同缺陷類(lèi)型和形狀將產(chǎn)生不同類(lèi)型的信號(hào)。其優(yōu)點(diǎn)是檢測(cè)精度高、探測(cè)靈敏度高，檢測(cè)速度快，能檢測(cè)待檢測(cè)管材的表面及亞表面，且不受待檢測(cè)方管表面油污等雜質(zhì)的影響。缺點(diǎn)是易將非缺陷結(jié)構(gòu)判定為缺陷，誤檢率較高，檢測(cè)分辨率不容易調(diào)整。

There are five main methods to detect the surface defects of square tubes: one is eddy current testing. Eddy current testing has many forms, such as conventional eddy current testing, far-field eddy current testing, multi-frequency eddy current testing and pulse eddy current testing. Using eddy current sensors to induce metal, different types and shapes of defects on square tubes surface will produce different types of signals. It has the advantages of high detection accuracy, high detection sensitivity, fast detection speed, can detect the surface and sub-surface of the pipe to be tested, and is not affected by the impurities such as oil contamination on the surface of the square pipe to be tested. The disadvantage is that it is easy to judge the non-defective structure as a defect, the false detection rate is high, and the detection resolution is not easy to adjust. 二超聲波檢測(cè)

Two-Ultrasound Detection

利用超聲波進(jìn)入物體遇到缺陷時(shí)，一部分聲波會(huì)產(chǎn)生反射，發(fā)射和接收器可對(duì)反射波進(jìn)行分析，就能異常精確地測(cè)出缺陷來(lái)。超聲波檢測(cè)常用于鍛件檢測(cè)，檢測(cè)探傷靈敏度高，但是不易檢查形狀復(fù)雜的管材，要求被檢查的方管表面有一定光潔度，并需有耦合劑充填滿(mǎn)探頭和被檢查表面之間的空隙。

When ultrasound enters an object and encounters a defect, a part of the acoustic wave will produce reflection. The transmitter and receiver can analyze the reflected wave, and the defect can be detected abnormally and accurately. Ultrasound detection is often used for forging detection, which has high detection sensitivity, but it is not easy to inspect the pipe with complex shape. It requires that the surface of the inspected square pipe should have a certain degree of smoothness, and the coupling agent should be used to fill the gap between the probe and the inspected surface.

三磁粉法檢測(cè)

Detection by three magnetic powder method

磁粉法檢測(cè)的原理是在方管材料中實(shí)現(xiàn)磁場(chǎng)，根據(jù)缺陷處的漏磁場(chǎng)與磁粉的相互作用，當(dāng)表面和近表面有不連續(xù)或缺陷時(shí)，則在不連續(xù)處或缺陷處磁力線發(fā)生局部畸變產(chǎn)生磁極。其優(yōu)點(diǎn)是設(shè)備投資少，可靠性高，具有直觀性。缺點(diǎn)是操作成本高，不能對(duì)缺陷準(zhǔn)確分類(lèi)，檢測(cè)速度較低。

The principle of magnetic particle method is to realize magnetic field in square tube material. According to the interaction between leakage magnetic field at defect and magnetic particle, when there is discontinuity or defect on surface or near surface, the magnetic line at discontinuity or defect will distort locally to produce magnetic pole. Its advantages are less investment in equipment, high reliability and intuition. The disadvantage is that the operation cost is high, the defect can not be accurately classified, and the detection speed is low.

四紅外線檢測(cè)

Four Infrared Detection

通過(guò)高頻感應(yīng)線圈，在方管表面產(chǎn)生感應(yīng)電流，感應(yīng)電流會(huì)導(dǎo)致缺陷區(qū)域消耗更多電能，引起局部溫度升高，通過(guò)紅外線檢測(cè)局部溫度，從而確定缺陷深度。紅外線檢測(cè)一般用于平直表面的缺陷檢測(cè)，不適合檢測(cè)表面不平整金屬。

Through high frequency induction coil, induction current is generated on the surface of square tube. Induction current will cause more electric energy to be consumed in defect area, causing local temperature to rise. The defect depth can be determined by infrared detection of local temperature. Infrared detection is generally used for flattening surface defect detection, not suitable for detecting surface irregularity metal.

五漏磁檢測(cè)

Five magnetic flux leakage detection

方管的漏磁檢測(cè)方法和磁粉檢測(cè)方法非常相似，適用范圍、靈敏度和可靠性較磁粉檢測(cè)方法更強(qiáng)。

The magnetic flux leakage testing method of square tube is very similar to that of magnetic powder testing method, and its application scope, sensitivity and reliability are stronger than that of magnetic powder testing method.