Testing the technical state of gas-transferring unit compressor cases and their repair under the conditions of compressor stations

Problems related to the use of nondestructive testing methods during engineering diagnostics of the cast cases of compressors that are used in gas-transfer units that operate in gas-main pipelines are considered. Features of the renewal of cases with especially large flaws under the conditions of compressor stations are considered. Typical flaws that are detected during diagnostics of natural-gas compressors are systematized.     

Acoustic-emission study of the possibilities of localizing flaws of a welded joint during cooling

A method of localizing acoustic-emission signals from flaws of a welded joint during its cooling is considered. Aluminum and titanium inserts were used to simulate flaws of the welded joint. The developed technique of clustering made it possible to exclude noise accompanying the processes of welding and cooling the welded joint. The welded specimens were tested on an MTS-50 loading machine. At the finishing stage, specimens with double-sided welded joints containing titanium inserts were subjected to metallographic analysis.     

Classification of flaws in ultrasonic and X-ray testing

Classification of flaws in welded joints during X-ray and ultrasonic nondestructive testing are considered. The consideration is focused on the parameters of flaws that affect the reliability of the tested item. Recommendations are made to improve identification of a flaw’s shape and type via relationships between test signatures and to assess parameters involved in calculations of the strength and service life of a tested item.     

Testing of metal structure during X-Raying of welded joints

The possibility of using images of structural origin observed in X-ray pictures of welded joints as a source of information about the structure of tested metal is considered. Practical recommendations for testing welding flaws and the state of metal structure in welded joints via X-raying are given.     

Laser acoustic method for the inspection of flaws in metals and the metallized coatings of dielectrics

The propagation of acoustic waves in an aluminum specimen without flaws and in specimens with artificial flaws is considered. A method for the combined diagnostics of metal surfaces of materials using the developed experimental system was suggested on the basis of the performed analysis of the time travel and reflection diagrams of ultrasonic waves.     

Estimates of Flaw Detectability in Welded Joints by X-ray Testing

The paper presents formulas for estimating detectability of three-dimensional and planar flaws of arbitrary dimensions, shapes, depths, and orientations in welded joints. Calculations and experimental data concerning the detectablity of flaws in welded joints by the X-ray method are discussed.     

Computer panoramic tomography for industrial application

Problems of the development and application of a high-capacity X-ray tomograph intended for testing bar-type fuel elements are considered. The tomograph created by the authors and designed for detecting and measuring flaws in welded joints in an automatic mode is briefly described, and its performance characteristics are presented. A technique for measuring flaws using reconstructed panoramic images, which is optimal for rejecting defective fuel elements under the conditions of a technological conveyor, is presented. The results of experimental tests of the tomograph involving automatic measurements of pore-type flaws in different detection modes are presented. The results of this study can be useful for other industrial applications of X-ray tomography.     

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.     

基于"生死单元"技术的焊缝缺陷模拟

应用有限元方法，计算分析带几何缺陷焊接接头力学性能。通过杀死焊接接头有限元模型中相应位置的单元，模拟存在的几何缺陷。计算分析带有气孔或咬边缺陷的焊接接头应力分布特性和应力集中程度，验证了应用生死单元模拟几何缺陷的有效性。通过对建模方法的比较，表明生死单元技术能够灵活模拟缺陷。     

Thermal Imaging Investigations in Experimental Mechanics

The possibilities of using thermal imaging methods in experimental mechanics are considered. Examples of diagnostics of flaws in products and investigation of specifics of the processes of deformation of structural materials and engineering elements with the use of a TKVr-IFP matrix infrared imager are given.     

Testing of discs of turbine rotors of gas compressors with the dye penetrant nondestructive testing technique

The special features of diagnostics of turbine discs of ΓTK-10-4 gas compressor units tested by the dye penetrant flaw detection method are considered. It is shown that disc blades must be dismantled and carefully mechanically cleaned, the spots in discs where such flaws as cracks are generated most often being analyzed, thereby reducing the searching and detection time.     

Determination of Faulty-Fusion Dimensions in a Cross Section of a Welded Seam by Radiographic Testing

The principles of using radiographic testing for measuring the faulty-fusion depth in a cross section of a welded seam are considered. The results of verification of the technique through examination of artificial and natural flaws are presented and some examples of the technique’s use in manufacturing are shown.__________Translated from Defektoskopiya, Vol. 41, No. 4, 2005, pp. 63–69.Original Russian Text Copyright © 2005 by Kruglova, Knyazyuk, Kortov.     

X-ray testing and engineering diagnostics

The possibility of using data obtained via X-ray testing as information about an object’s quality is considered. Such an option is discussed for a computer-aided version of this approach for engineering diagnostics of welded joints tested with an X-ray method.     

Attempt Towards the Replacement of Radiography with Phased Array Ultrasonic Testing of Steel Plate Welded Joints Performed on Bridges and Other Applications

This study was carried out to demonstrate if the phased array ultrasonic testing (PAUT) can be adopted as a suitable substitute of the radiography testing (RT) of steel plate’s welded joints required by codes and standards related to some projects such as bridges construction and inspection according to AWS D1.5 Bridge welding code. Such adoption, if approved, can realize considerable cost saving without taking any additional risk. The two cited inspection techniques had been applied to test four butt welded joints performed on steel plates having thicknesses up to 35 mm. These welded joints had been performed by shielded metal arc welding (SMAW) and containing selected artificial flaws. The comparison between the detection capabilities and characterization of flaws in the welded joints by the two inspection techniques reveals that; PAUT improves the detection capability and sizing of flaws in the welded joints and it can replace RT reliably in case of applying a suitable PAUT procedure that includes simultaneous application of sectorial scan from both sides of the welded joints axes by using encoder with wide active aperture phased array probes and applying supplemental manual scanning for edge testing.     

An Intelligent System for Vibrodiagnostics of Oil and Gas Equipment

An intelligent system for the diagnostics and monitoring of oil and gas equipment with a computerized device for identification measurements of vibration signals is described. The system operates based on the expert knowledgebases of the FRASH- and S-methods and the databases of tabulated quantitative and qualitative properties of objects. It has been shown that the temporal properties of the condition of objects and their autocorrelation functions are clearly described by identification parameters. The example of applying the intelligent technology of identification measurements to the vibration-based diagnostics of an HM 12500-210 no. 12 pump unit has shown that such diagnostics and monitoring is more efficient as it recognizes not only states that include groups of flaws with similar characteristics but also the flaws themselves. An instance of the intelligent computer-aided system for the diagnostics and monitoring of oil and gas equipment using modern information–communication technologies is presented.     

Identification of sources of acoustic emission on casting flaws in cast parts

Peculiarities of the estimation of the state of sections with casting flaws in cast parts using acoustic-emission (AE) method are considered. The dynamics of variations in AE parameters for developing flaws during mechanical tests is analyzed. The methods for distinguishing useful information of AE signals from the regions of localization of casting flaws are revealed.     

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).     

Data-processing algorithms for automatic operation of ultrasonic systems with coherent data processing

Two algorithms for the automatic determination of flaw parameters during ultrasonic testing of welded joints with a high level of structural background noises are considered. The experimental data collected in the course of automated ultrasonic testing (AUT) using Avgur series with coherent processing of data (Avgur 4.2 and Avgur 5 systems) and the results of the assessment of nondestructive testing data are used. The first algorithm is used to identify zones where flaws may be located. This algorithm is applied after running AUT in the search mode. If the parameters of the algorithm application are selected properly, this algorithm makes it possible to determine the coordinates and the conventional length of the identified flaws. The second processing algorithm is intended to determine the flaws actual length and height. For its operations the algorithm uses the images obtained from coherent data processing. Results of testing methods for automatic (computer) determination of flaw parameters are cited. These results are obtained by the Avgur system during testing of austenite welded joints in stainless-steel pipes with a diameter of 325 mm and in perlite-steel pipes of various diameters.Translated from Defektoskopiya, Vol. 40, No. 12, 2004, pp. 3–15.Original Russian Text Copyright © 2004 by Badalyan, Vopilkin, Dolenko, Orlov, Persiantsev.This revised version was published online in April 2005 with a corrected cover date.     

Effect of post weld aging treatment on tensile properties of electron beam welded AA2219 aluminum alloy

Aluminum alloy 2219 (Al-6.5%Cu) is a favourite age hardenable alloy for aerospace applications because of its excellent welding characteristics. Though AA2219 has got an edge over its 6000 and 7000 series counterparts in terms of weldability, it also suffers from poor joint strength when welded. In this investigation an attempt has been made to improve the welded joint strength through post weld aging treatment. This paper presents the effect of post-weld aging treatment on tensile properties of electron beam welded AA2219 aluminum alloy. Square butt joints were fabricated using an electron beam welding (EBW) machine of 100 kV capacity. The joints were given post-weld artificial aging treatment. Tensile tests were carried out using 100 kN, electro-mechanical controlled universal testing machine. It is found that the post-weld aging treatment is beneficial for improving weld metal hardness and tensile properties. This is mainly due to the uniform distribution of CuAl₂ precipitates in the weld metal region in post-weld aged joints compared to as welded joints as evident from weld metal microstructure.     

Electrochemical treatment of welded seams before penetrant testing

The effect of the abrasive treatment of welded seams performed before penetrant testing on opening and polishing of the surface flaws is studied experimentally. It has been shown that, owing to the electrochemical treatment, the mouths of flaws are cleaned of a metal layer and the microroughness of the surface and its background luminescence after development decrease considerably, thus providing high-quality luminescent penetrant testing.