Steel pipe longitudinal defect magnetic leakage detection device based on rotary magnetizing field

Abstract

The invention discloses a steel pipe longitudinal defect magnetic leakage detection device based on a rotary magnetizing field. The device comprises a rotary magnetizer, an excitation power supply, an area array sensor array, an area array sensor array support, a filter, an amplifier and an A / D (analog-to-digital) converter. The excitation power supply provides three-phase asynchronous alternating current for the rotary magnetizer, and the rotary magnetizing field is generated inside the rotary magnetizer. The annular area array sensor array is fixed into the rotary magnetizer through the support and fully circumferentially covers a steel pipe. When the steel pipe passes the detection device, the rotary magnetizing field fully, circumferentially and uniformly magnetizes the steel pipe. If the steel pipe has a longitudinal defect, a defect magnetic flux leakage field is generated, picked by a sensor at a position corresponding to the defect and converted into an electric signal, the electric signal is transmitted to a computer sequentially through the filter, the amplifier and the A / D converter, and the longitudinal defect is detected. The steel pipe is fully, circumferentially and uniformly magnetized by the device, longitudinal defect detection efficiency is improved, and cost is reduced.

Description

technical field [0001] The invention relates to the field of nondestructive testing, in particular to a magnetic flux leakage flaw detection device for longitudinal defects of steel pipes based on a rotating magnetization field. Background technique [0002] As an important transportation and support material, steel pipes are widely used in petrochemical and infrastructure construction. With the rapid development of industrial modernization, the demand for high-quality steel pipes is increasing. At present, my country has the world's most advanced steel pipe production technology and the latest pipe rolling unit, and the pace of steel pipe production is getting faster and faster. According to the requirements of the American Petroleum Institute (API), all steel pipes must undergo 100% quality inspection before leaving the factory. [0003] As an efficient detection method, magnetic flux leakage detection can effectively detect internal and external defects of steel pipes, ...

AI Technical Summary

Problems solved by technology

Both of the above two methods can realize the detection method that the magnetizer is fixed and the steel pipe moves forward in a straight line. However, since the above two magnetization methods are for partial magnetization of the steel pipe, the magnetization is not uniform at the junction of the partitions, which will increase the difference in circumferential sensitivity. Reduced detection reliability

In addition, the mechanical structure and signal system of the two are complex, occupy a large space, cost high, and have low practicability

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