O. A. Bulychev

Computerized Magnetic Testing of Oil Pipes

The design and underlying principles of a new system of the magnetic testing of oil pipes based on anisotropic magnetoresistive transducers are considered.

Revealing surface microcracks in metal articles by excitation of high-frequency eddy currents with subsequent infrared-camera imaging

A method has been developed for revealing microcracks in metal articles by excitation of high-frequency eddy currents with subsequent recording of the temperature relief with an infrared camera. The sensitivity, as measured by outside crack opening, is 8 μm; this corresponds to Level B of magnetic-powder testing. The method is technologically easier to implement than magnetic-powder one and can therefore replace the latter in many problems of testing.

The UMD-104M device for testing reusable oil-well tubing

The optimal structural scheme and special features of a new automated device for the magnetic flaw detection of seamless pipes and electric-welded oil-well tubing in the process of their production and recovery of used pipes are considered. It is shown that the application of state-of-the-art technologies for manufacturing single-chip thin-filmed high-resolution matrix transducers substantially increases the functional capabilities of a flaw detector and not only ensures the reliable detection of all inadmissible flaws, such as discontinuities in metal, the wear of pipe walls, and displacement of the edges of a welded seam, but also provides higher reliability indices of sensors (breakdowns are minimal).

Estimating the possibility of the magnetic detection of microflaws in weld seams of longitudinal electric-welded pipes manufactured by butt high-frequency welding

Fragments of longitudinal electric-welded pipes were inspected in the state after their manufacturing. The presence of flaws, like surface cracks with openings of nearly 10 μm, were detected by means of optical testing in the zone of a weld seam. It was shown that such cracks can be easily detected at the УMД-101M magnetic nondestructive testing station.

The UMD-101M plant for automated bulk magnetic nondestructive testing of quality of electric-welded pipes

The optimal structural scheme and special features of the new automated plant for magnetic nondestructive testing of electric-welded pipes in a technological industrial line, which meets contemporary demands, are considered. It has been shown that the use of computer technologies and thin-filmed high-resolution transducers provides significant improvement of operating possibilities of a flaw detector and makes it possible to detect, not only such flaws as discontinuities in metal and displacement of edges, but also flaws caused by failures in welding regimes, such as burns and cohesion of edges near a welded joint.

The effect of the anisotropy of magnetic properties of electrical steel on magnetic losses in power transformer cores

The distribution of the magnetic flux in the zone of rod contacts is investigated using the model of transformer cores. The effect of the anisotropy of magnetic characteristics of steel on magnetic losses and the transformer building factor is demonstrated. A method for estimation and forecasting of the building factor value is proposed. The investigation was performed using anisotropic electric steel of the 3408–3409 grades manufactured at OOO VIZ-STAL’.

A magnetic scanner based on residual magnetization used for testing ferromagnetic articles

A setup was developed for visualization of flaws in residual magnetic fields using thin-film matrix probes, whose principle of operation is based on the anisotropy effect of the magnetic resistance in ferromagnetic films. Although the flaw-detecting ability of this technique is the same as that of the magnetic-powder technique, the setup allows automation of the testing process and increases its effectiveness. The inspection is performed with a gap between the detectors and a surface of up to 2 mm. The fields of application are machine building, oil and gas industry, etc.

Computational relationships for the development of software for calculating magnetostatic fields from flaws in arbitrarily shaped ferromagnetic products

Based on the integral equation for the stray magnetic field strength inside a magnetized article, computational relationships have been derived in the form of a matrix equation that is convenient when developing software for modeling the distribution of magnetization in arbitrarily shaped articles with different flaws and for calculating and imaging external magnetic fields of the magnetized article. On this basis, a program has been developed that is most suitable for the case where the article boundaries and flaws can be sufficiently accurately defined on a three-dimensional grid with identical rectangular cells.

The UMD-121 device for the automated magnetic monitoring of the weld seams of longitudinally welded pipes that are 168–530 mm in diameter

An optimum block-schematic diagram and the distinctive features of a novel automated device that corresponds to modern requirements for the magnetic defectoscopy of the weld seams and heat-affected zones of electrically welded pipes that are 168–530 mm in diameter in the flow of their production are considered. It is shown that the application of computer technologies and thin-film transducers with high resolution allows one to substantially increase the functional possibilities of a defectoscope and provides the detection of not only defects of the type of metal discontinuities and edge displacements, but also defects that are caused by the violation of welding modes resulting in the burn and edge-cling defect types in the area of a weld seam.

A study of the possibility of detecting surface defects in ferromagnetic products using a pyroelectromagnetic method

A new method for detecting surface cracks in ferromagnetic products by means of combined magnetization and defect zones by the temperature relief of a surface using an infrared camera (infrared imager) is proposed. Its physical principles and testing procedure are outlined. Experimental data obtained on steel specimens with surface microcracks are given.