Composite steel pipe defect detecting device and composite steel pipe defect detecting method

Abstract

The invention provides a composite steel pipe defect detecting device and a composite steel pipe defect detecting method, and belongs to the technical field of non-destructive detection. The device comprises an eddy current probe, eddy current detection coils wrapped on the outer surface of the eddy current probe and a driving device connected with the eddy current probe. The method comprises the following steps of: (a) inserting the cylindrical eddy current probe into the inner wall of a composite steel pipe to be detected; (b) detecting the composite steel pipe to be detected by the eddy current detection coils wrapped on the outer surface of the eddy current probe to acquire eddy current signals, and executing a step (c) when the impedance amplitude of the detected eddy current signals on an impedance plane graph exceeds a set alarm amplitude range; executing a step (d) when the impedance amplitude of the detected eddy current signals on the impedance plane graph does not exceed the set alarm amplitude range; (c) recording the composite steel pipe to be detected as an unqualified composite steel pipe; and (d) recording the composite steel pipe to be detected with a qualified mark. By the device and the method, defects of the composite steel pipe to be detected are quickly detected with high sensitivity.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing, in particular to a defect detection device for a composite steel pipe and a defect detection method for a composite steel pipe. Background technique [0002] At present, composite steel pipes (common composite steel pipes, such as bimetallic composite steel pipes, which include carbon steel pipes on the outer layer and alloy pipes on the inner layer) have been widely used in oil and gas, petrochemical, salt chemical, electric power and metallurgy, etc. industry. Bimetal clad steel pipes may have the following problems during or after the cladding process: There may be defects (such as cracks or inclusions) on the body and weld of the alloy pipe, or defects only on the weld. If the above-mentioned defects exist in the alloy pipe, the anti-corrosion effect of the bimetallic clad steel pipe (that is, the anti-corrosion effect of the inner lining) will be lost. Without the protectio...

AI Technical Summary

Problems solved by technology

Bimetal clad steel pipes may have the following problems during or after the cladding process: There may be defects (such as cracks or inclusions) on the body and weld of the alloy pipe, or defects only on the weld

Without the protection of the inner lining layer, the carbon steel pipes that directly contact the outer layer of the conveying medium and play a pressure-bearing role are easily corroded quickly, which may lead to leakage of the pipeline and even accidents.

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