CINDE Journal Abstracts
January/February 2008 |
| A Contribution to Phased Array Ultrasonic Inspection of Welds, Part 3: Sizing Capability - by Peter Ciorau Part 3 of the series presents the sizing capability for length, height, outer and inner ligament for specific implanted weld defects in training samples and mock-ups with thickness between 6.4-52 mm. It is discussed the influence of beam angle on sizing the lack of fusion defect. More than 50 implanted weld defects with 50% crack population were sized using high-frequency (5-10 MHz) linear array probes. The correlation between the design/manufacturer flaw size and PAUT data for length, height and ligament is graphically presented. It was concluded the length is oversized by 2-6 mm, height and inner ligament are undersized by 0.2 to 0.5 mm, and outer ligament is oversized by 0.5 mm. The sizing results were based on non-amplitude techniques and pattern display of S- and B-scan. The sizing capability is far better than ASME XI tolerances for performance demonstration and comparable to TOFD ideal tolerances. |
January/February 2008 |
| New Tools for Remote Visual Inspection Productivity - by Lindsay Theile Remote Visual Inspection (RVI) utilizes video based inspection scopes, borescopes, fiberscopes or other forms of camera systems to remotely see where our eyes cannot go. Storing images was done via various types of still or video cameras attached to the eyepiece. As technology progressed, cameras were replaced with digital storage devices like flash cards. Today’s videoprobe systems now feature these as well as USB ports, built in DVD burners and Ethernet connections. It is now possible for the quality engineer to view a real time inspection from any place where an internet connection is available. With these interface and storage abilities there is now a need for improved reporting capabilities. Menu Directed Inspection (MDI) was developed so that the QA department can actually design an inspection route into the videoprobe system to guide the inspector through the application and ensure a more accurate inspection. |
January/February 2008 |
| VISUAL INSPECTION AND MULTI-TECHNOLOGY ASSESSMENT METHOD FOR ABNORMAL DISPLACEMENT OF HEAVY DUTY OVERHEAD CRANES - by F.Lefebvre This assessment method is based on years of experience in overhead crane visual inspection and analysis. The main concern of the technique is to identify and fix the lateral and diagonal displacement of cranes originating from miscellaneous causes. The assessment method describes the steps to follow when a displacement problem is observed on an overhead crane. The analysis includes runways visual inspection, visual inspection of the runways substructures, visual analysis with cameras, monitoring of the runways substructure and runways displacement with indicators and acquisition system. The method is working by elimination to converge toward the cause of the abnormal displacement. It includes a few techniques of telemetry and traditional precision measurements. The method is in accordance with the ASME1,2 and CSA3 standards and with the practices of the industry. On site anecdotes and experiences are presented in conjunction with the applicable standards to provide quick tips to point out a massive amount of interrelated problems. |
November/December 2007 |
| LASER-AIR HYBRID ULTRASONIC TECHNIQUE FOR DYNAMIC RAILROAD INSPECTION APPLICATIONS - by S. Kenderian, D. Cerniglia, B. B. Djordjevic, G. Garcia Laser-Air Hybrid Ultrasonic Technique (LAHUT) combines laser generation with air-coupled detection of ultrasound. The technique is non-contact and has the characteristic of operating from remote distances. Acoustic wave laser-generation apparatus can be meters away from the interrogated surface while air-coupled detection standoff can be on the order of several centimeters. The technique has the unique capability of interrogating structural materials in their true industrial environment. Dynamic tests are performed on parts with complex geometry, limited accessibility and curved surfaces. Also, dark and rough finish surfaces, which significantly reduce the efficiency of optical detection techniques, can be interrogated successfully. These characteristics make the LAHUT ideal for many industrial applications including the railroad industry. It was developed for railroad inspections targeting the most critical cracks in rails and wheels. State of the art inspection techniques available to the railroad industry often miss Vertical Split Head (VSH) and Transverse Detail Defect (TDD), which lie in unfavorable positions and orientations in the rail head. No method exists to perform dynamic inspections of the rail base or any part of the railroad wheel. Laboratory experiments were performed for the detection of TDD and Proof Of Concept (POC) field tests were performed for VSH, rail base cracks, thermal fatigue cracks along the wheel flange and tread and subsurface Shattered Rim Cracks (SRC) along the wheel tread. The results were successful and highly repeatable. The technique lends itself for digital collection and automated processing of data making the LAHUT a very strong candidate for next-generation railroad inspection technique. |
November/December 2007 |
| CONTRIBUTION TO CRACK SIZING BY PHASED ARRAY ULTRASONIC TECHNIQUES, PART 2: COMPARISON WITH OPTICAL, MAGNETIC PARTICLES, FRACTURE MECHANICS AND METALLOGRAPHY FOR LAST SIGNIFICANT CRACK TIP - by PETER CIORAU The paper presents phased array results for 1-D linear array probes of high frequency (7-10 MHz) in L-, and S-waves for detecting the crack shape and the last significant tip. Fatigue and stress-corrosion cracks with height ranging from 1.6 mm to 20.4 mm were detected in welded samples, piping welds and straight bars with thickness between 6 mm to 38 mm. The results of S-scan display are compared with different methods: optical, magnetic particles, fracture mechanics and metallography. The experimental results concluded the undersizing trend of PAUT in detecting the last crack tip or closure, in spite of using dynamic depth focusing, and/or focusing on crack tip. The average undersizing error is – 0.4 mm. This error increases for cracks with depth >12 mm. The largest errors occur when the crack is sized from outer service coupled with initiation from the outside surface with propagation towards the inside surface. These errors were reduced by a combination of shear and longitudinal waves and by increasing the angular resolution. |
September/October 2007 |
| A CONTRIBUTION TO PHASED ARRAY ULTRASONIC INSPECTION OF WELDS, PART 1: DATA PLOTTING FOR S-AND B-SCAN DISPLAYS - by PETER CIORAU Part 1 of the paper presents the detection and sizing capability based on image display of sectorial scn. Examples are given for different types of weld defects: toe cracks, internal porosity, side-wall lack of fusion, underbead crack, inner-surface breaking cracks, slag inclusions, incomplete root penetration and internal cracks. Based on combination of S-can and B-Scan plotted into 3-D isometric part, the defect features could be reconstructed and measured into a draft package. Comparison between plotted data and actual defect sizes are also presented. |
July/August 2007 |
| Comparison of Solid Highlighter Materials for Thermography - by M. Genest, D. S. Forsyth, X. Maldague Bare metal surfaces are difficult to inspect with flash thermography due to the high reflectivity
and low emissivity of metal surfaces. Often black paint is used to prepare these surfaces for
inspection. The additional time required to apply, dry, and then remove paint after inspection can
be a significant barrier to using thermographic inspection techniques in these applications. This
paper examines the use of solid “highlighter” materials instead of paint to provide desirable
surface characteristics and ease of use. Both positive pressure and vacuum methods were used to
apply a variety of materials to metal test specimens, which were then inspected with a
commercial pulsed flash thermography system. A vacuum-applied black latex material provided
surface performance close to that of black paint without the extra burden of paint application and
removal.
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July/August 2007 |
| DETECTION OF MECHANICAL DAMAGE USING THE MAGNETIC FLUX LEAKAGE TECHNIQUE - by L. Clapham, V. Babbar, and James Byrne Since magnetism is strongly stress dependent, Magnetic Flux Leakage (MFL) inspection tools have the potential to locate and characterize mechanical damage in pipelines. However, MFL application to mechanical damage detection faces hurdles which make signal interpretation problematic:
1) the MFL signal is a superposition of geometrical and stress effects,
2) the stress distribution around a mechanically damaged region is very complex, consisting of plastic deformation and residual (elastic) stresses,
3) the effect of stress on magnetic behaviour is not well understood.
This paper summarizes recent results of experimental and modeling studies of MFL signals resulting from mechanical damage. In experimental studies, mechanical damage was simulated using a tool and die press to produce dents of varying depths in plate samples. MFL measurements were made before and after selective stress-relieving heat treatments. These annealing treatments enabled the stress and geometry components of the MFL signal to be separated. In general, geometry effects scale with dent depth and tend to dominate in deep dents, while stress contribution to the MFL signals is relatively constant and is more significant for shallow dents. The influence of other parameters such as flux density and topside/bottomside inspection was also quantified.
In the finite element analysis work, stress was incorporated by modifying the magnetic permeability in the residual stress regions of the modeled dent. Both stress and geometry contributions to the MFL signal were examined separately. Despite using a number of simplifying assumptions, the modeled results matched the experimental results very closely, and were used to aid in interpretation of the MFL signals.
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May/June 2007 |
| Radiographic Evaluation of Corrosion and Deposits: IAEA Co-ordinated Research Project on Large Diameter Steel Pipes - by U. Zscherpel, I. Einav, S. Infanzon and J. Zirnhelt The principle of corrosion measurement/monitoring by means of tangential film-based radiography is already known. Most of this experience, however, is limited to qualitative determination of internal defects. The ability to reliably measure remaining wall thickness in pipes has not yet been established.
The International Atomic Energy Agency has organized a Co-ordinated Research Project bringing together twelve Member States to study “validation of protocols for corrosion and deposits determination in large diameter pipes by radiography”. The general scope of the project covers radiographic measurement of corrosion and deposits in straight and bent large diameter (>160mm) pipes made of carbon or stainless steel corroded/eroded on the outer or inner surfaces with or without insulation.
It is expected to define the limits of detection for each radiation source using the tangential method and to explore the double wall technique beyond this limit.
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March/April 2007 |
| COMPARISON RADIOGRAPHIC AND AUTOMATED ULTRASONIC INSPECTION OF PIPELINE TIE-IN WELDS - by THOMAS CONNELLY, BEN GROSS In recent years the use of automated ultrasonic Inspection (AUT) for pipeline girth welds has been rapid growth and is now used almost exclusively for all gas metal arc welding (GMAW) girth weld inspection. The following paper reviews some of the major features of ultrasonic inspection by comparison to conventional Film Radiography (RT) and reviews the use of ultrasonic inspection for pipeline and tie-in welds. |
March/April 2007 |
| AUT INSPECTION OR ORMEN LANGE AND LAGELED PIPELINES - by DAVID CZIRAKI Combining the skills and knowledge from many countries, the Ormen Langel Langeled sub-sea gas pipeline project demonstrated constructive technological cooperation at a global level. The Canadian contribution highlighted the commitment to advancing the recognition and growth of the phased array AUT inspection of pipeline girth welds. This article briefly describes the project and discusses several of the technical challenges encountered. |
January/February 2007 |
| TRANSVERSE HARDNESS PHOTOTHERMAL PAHSE IMAGING AND DEPTH-PROFILOMETRY OF HEAT TREATED STEELS - by Y.LIU, A. MANDELIS, N. BADDOUR, C.H. WANG A method to image near –surface hardness profiles of heat-treated case-hardened steels using laser infrared photothermal radiometric phase imaging is described. It is shown that thermophysical and mechanical transverse inhomogeneity profiles in industrial case hardened steel samples are well correlated. Phase surface scanning imaging leads to a practical criterion for assessing transverse hardness homogeneity. A simple method based on phase imaging is proposed as a quantitative criterion to determine which steel samples should be rejected for thermal-wave depth-profilometric reconstruction of thermal diffusivity. Having developed this laterally hardness homogeneity criterion, we selected laterally homogeneous case-hardened industrial steels for thermal-wave frequency scans in order to perform depth profilometry of their thermal diffusivity. The reconstructed thermal diffusivity depth profiles from the samples were compared to the results of microhardness testing after each step of heat treatment: carbonitriding and quenching. The comparison showed that there is a good to excellent anti-correlation between hardness and thermal diffusivity profiles for both carbonitrided and quenched samples with 0.02” case depth and gradually worsening anti-correlation trends for 0.04” and 0.06” case depths. |
January/February 2007 |
| IMPROVEMENT IN LIQUID PENETRANT TEST SENSITIVITY BY THERMAL TREATMENT - by SANJOY DAS, P.R. VAIDYA & B.K. SHAH The modern trend in the nondestructive testing industry is to increase sensitivity of the technique. Considerable effort is being devoted to the manipulation of test parameters to improve sensitivity. The aim is to detect finer flaw in components and amplify the detected signal for extracting more information. Liquid Penetrant Testing (PT) is no longer an exception. Unlike other nondestructive techniques, PT has fewer parameters available at the inspector’s hands. In this paper, thermal effect on test sensitivity has been explored. |
January/February 2007 |
| THE RELATIONSHIP BETWEEN ULTRASONIC WAVE VELOCITY, STRAIN AND MICROSTRUCTURE IN MILD STEEL BAR - by F.K. LIEW, S. HAMDAN, M.S. OSMON This paper presents the nondestructive testing (NDT) method to determine the resultant stresses in mild steel bar usually employed in structures. The technique utilized ultrasonic pulse-echo that determined the ultrasonic wave velocity change due to torque applied between bolt and nut. Mild steel bar with nominal diameter of 18mm and 25mm was used. The specimen was loaded by means of a torque wrench, which gave the required amount of momentum (~240Nm). This was carefully achieved manually. In order to measure the strain, strain gauges were employed. The direct strain gauge method gave the strain values. The experiment had been carried out in a controlled environment with constant temperature. Microstructures were characterized by scanning electron microscopy (SEM). The relationships between wave velocity, strains and microstructure were investigated. The test results indicated that ultrasonic wave velocity decrease with the applied torque. This was due to degradation or loss of strength of the material. This study also showed that ultrasonic wave velocity had a strong dependency on microstructure especially the porosity of the specimen. |
November/December 2006 |
| Automated Ultrasonic Pipe Weld Inspection - Part 2 - by W.A. Deutsch, P. Schulte, M. Joswig, R. Kattwinkel This article contains a brief overview on automated ultrasonic welded inspection for various pipe types. Some inspection steps might be carried out with portable test equipment (e.g. pipe end test), but the weld inspection in all internationally relevant specification must be automated. The pipe geometry, the production process, and the pipe usage determine the number of required probes. Recent updates for some test specifications enforce a large number of ultrasonic probes, e.g. the SHELL standard. Since seamless pipes are sometimes replaced by ERW pipes and LSAW pipes by SSAW pipes (in both cases to save production cost), the inspection methods change gradually between the various pipe types. Each testing system is unique and shows its specialties that have to be discussed by supplier, testing system user and final customer of the pipe. |
November/December 2006 |
| Application of Time-Of-Flight Diffraction for Weld Inspections - by M. Moles Time-Of-Flight Diffraction (TOFD) is becoming widely used for weld inspections in the petrochemical and other industries. This unique ultrasonic technique has big advantages in speed, detection of midwall defects and is the most accurate defect sizing technique in general use. However, TOFD images require skilled interpretation, and TOFD has significant dead zones on the outside and inside surfaces. In general, it is most reliable in conjunction with standard pulse echo techniques. This presentation will describe the TOFD technique, its advantages and limitations, and give some examples. The latest news on TOFD codes, guidelines and interpretation manuals will be provided. |
September/October 2006 |
| Automated Ultrasonic Pipe Weld Inspection - Part 1 - by W.A. Deutsch, P. Schulte, M. Joswig, R. Kattwinkel This article contains a brief overview on automated ultrasonic welded inspection for various pipe types. Some inspection steps might be carried out with portable test equipment (e.g. pipe end test), but the weld inspection in all internationally relevant specification must be automated. The pipe geometry, the production process, and the pipe usage determine the number of required probes. Recent updates for some test specifications enforce a large number of ultrasonic probes, e.g. the SHELL standard. Since seamless pipes are sometimes replaced by ERW pipes and LSAW pipes by SSAW pipes (in both cases to save production cost), the inspection methods change gradually between the various pipe types. Each testing system is unique and shows its specialties that have to be discussed by supplier, testing system user and final customer of the pipe. |
September/October 2006 |
| Phased Array Ultrasonic Technology Contribution to Engineering Critical Assessment (ECA) of Economizer Piping Welds - by P. Ciorau, D. Gray, W. Daks ECA team was asked by OPG-Inspection and Maintenance Services (IMS) to detect and size fatigue cracks in the counterbore area of carbon steel boiler feedwater piping welds (OD x t = 324 mm x 38 mm) of a thermal station. A sizing accuracy of ± 1 mm for the outer ligament was required. It was documented the fatigue cracks could be branched, change the morphology (from oxide-filled wide width to hair-tight aspect); they are tilt at different angles and the cracks have different shapes. Weld cap may not be totally removed in the field and access from component side is limited (Tee-welds). The technique must be validated on open and blind trials on retired-for-cause samples with service-induced cracks with known height. Some samples will undergo magnetic particle examination over the side faces for crack height confirmation. Other samples will be broken and fracture mechanics data will be compared with PAUT data. Some samples will be measured by high-accuracy optical methods. The field inspection will be witnessed by ECA engineer and by the customer. In order to get a reliable sizing, it was decided to report to ECA the crack ligament to outer surface. In this way, the errors due to crack morphology in reading the crack leg, inner surface irregularities and crack orientation in counterbore transition area (variable thickness) are eliminated. As a conservative decision, ECA will subtract -2 mm on outer ligament value reported by PAUT. |
July/August 2006 |
| X-ray Computed Tomography Aerospace Engine Inspection Applications - by David M. Craig & Daniel Girard Pratt & Whitney Canada installed a x-ray Computed Tomography (CT) scanner in the Materials Quality Assurance (MQA) Laboratory, Longueuil, Quebec in the early 1990's. It was originally used on development inspections related to wall thickness measurements of turbine blade and vane segment. However, advancements in computing capabilities combined with software enhancements have allowed a marked increase in the utilization of the CT scanner over the past 24 months. The capability to stack individual CT slice images and then produce a 3D model of the component or a flaw within the component has proved beneficial on many investigations. CT technology has found a niche application in support of failure investigation on engine accessory hardware such as sensors, speed probes, fuel manifolds, etc. Measurement of braze coverage on items such as fuel nozzles is another application where CT provides excellent image resolution on a small, highly complex, machined component. |
July/August 2006 |
| Complete Inspection of Friction Stir Welds in Aluminum using Ultrasonic and Eddy Current Arrays - by André Lamarre, Olivier Dupuis and Michael Moles Ultrasonic phased-array offers tremendous advantages for the inspection of Friction stir welds (FSW), a new method of joining metals using a solid state bonding process. Phased array ultrasonics can reliably detect all internal volumetric defects in FSW, such as cracks, inclusion, porosity and lack-of-penetration. Spot-focused beams improve detection, inspection angles can be optimized electronically and electronic scan of the beam normal to the welds gives rapid one-line scan inspection to assure full coverage. Furthermore, a technique using ultrasonic attenuation measurements shows the presence or absence of conditions for forming kissing bonds (or entrapped oxide defects). Also, eddy current arrays can be used for surface inspection, and can help to detect tight kissing bonds. Using all three approaches, the overall detection capability of kissing bonds is high. |
May/June 2006 |
| Rope NDT as Means to Raise Safety of Crane and Elevator Use - by V. Kotelnikov, V. Sukhorukov Steel rope NDT by magnetic flaw detectors is usual for mine hoist inspection through the world. But it is no ordinary by crane and especially by elevator inspection. However, magnetic NDT statistic data of 60 crane and 227 elevator ropes in use shows that about 23% of crane and 9% of elevator ropes should be discarded in accordance with actual discarding criterion in Russia. Russian State Rules for crane safe exploitation require the magnetic NDT while periodically inspection. But not all the inspecting companies meet it in Russia, contenting themselves by visual inspection only. This is not objective and does not provide rope inner faults detection.
That is a reason of rope break rather high percentage in general statistics of crane accidents and damages. Investigation of accidents with crane ropes in Moscow region in 2001 shows that they would de prevented by the magnetic NDT fulfilled timely. The elevator rope NDT problem is not so sharp but attention should de attracted to it to raise safety of elevators. |
May/June 2006 |
| The MFL Technique For Surface Flaws using Residual Magnetization Method with the MI (Magneto-Impedance) Sensor - by N. Kasai, T. Mizoguchi and K. Sekine The continuous magnetization is usually applied to the MFL testing for ferromagnetic specimens. In this case, the detectability of flaws may be strongly influenced by the stray field from magnetization equipment. This paper describes the MFL technique for surface flaws in ferromagnetic components by using the residual magnetization procedure without the stray field. The Magneto-Impedance (MI) device having highly sensitive to magnetic field has been used as a magnetic sensor to measure residual magnetic leakage flux density distributions arising from flaws, which are considered to be very low field strength. Firstly, the vertical components of residual magnetic leakage flux density distributions from the parallelepiped flaws were measured with the MI sensor, and the measured results showed to be symmetric with respect to the centre of parallelepiped flaws. A lot of noises were also measured because MI sensor is sensitive. Therefore, the wavelet transform decomposition and reconstruction techniques were applied for cancellation of these noises. Comparing these experimental results with ones by the ordinary Hall probe, excellent nature of this MI sensor having high sensitivity and high resolution in the proposed MFL system has been confirmed. Furthermore, a quantitative evaluation method for surface flaws based on the MFL technique by combined use of residual magnetizing procedure and the MI sensor has been presented. |
May/June 2006 |
| Principle Features of Metal Magnetic Memory Method and Inspection Tools as Compared to Known Magnetic NDT Methods - by A. Dubov Principal features of method of metal magnetic memory (MMM) as compared to known magnetic NDT methods are considered.
Among the basic features of the MMM method, that it is based on use of the own magnetic leakage field (SMLF), arising in ferromagnetic and paramagnetic products on accumulations of high-density dislocations. Magnetodislocation hysteresis underlying effect of metal magnetic memory, takes place as at manufacture of products during formation of internal stresses and at their operation under action of working loads.
It is impossible to obtain an information source like a self-magnetic field at any conditions with artificial magnetization in working constructions. Such information is formed and can be obtained only in a small external field, as the Earth's magnetic field is, in loaded constructions when deformation energy is a cut above the energy of the external magnetic field.
Features and uniqueness of magnetometric instruments are considered. The instruments have no world analogues.
Opportunities of the MMM method for the solution of actual NDT problems are:
- 100% quality control of machine-building products and heterogeneity of metal structure in a line production;
- Express quality control of welded joints in the united complex system of the factors structural-mechanical heterogeneity - defects of a weld - structural and technological stress concentrator;
- Early diagnostics of fatigue damages of metal at an estimation and forecasting of equipment lifetime. |
March/April 2006 |
| Acceptance Criteria for the Onshore and Offshore Pipeline and Steel Catenary Risers - by Thomas S. Connelly, Ben Gross An Engineering Critical Assessment (ECA) is a procedure that may be used to define and characterize critical imperfection sizes from which acceptance criteria for nondestructive examination (NDE) can be developed or confirmed. The paper will explain the objectives, adopted methodology, with comparisons to Workmanship criteria and imperfection sizing. The paper addresses NDE processes it is not intended to give descriptions of the methods. |
March/April 2006 |
| Performance Based Qualification: An NDT Service Industry Perspective - by John Zirnhelt The recently established Working Group 7 of ISO TC135 Subcommittee 7 is stimulating considerable discussion as it proposes to dispense with traditional ISO 9712 type programmes, substituting demonstration of competence as the sole factor in determining qualification of personnel. This activity challenges the industry to examine current training schemes, both class-room and on-the-job, and to consider the impact of such a move on the levels of qualification and assignment of service company personnel. |
March/April 2006 |
| IIW COMMISSION VC - Ultrasonically Based Weld Inspection - by E. Sjerve The IIW is an active organization in the area of weld-based topics. Within a structure of 15 independent commissions and another group of working committees, the IIW gathers together leading people from the perspectives of fabrication, maintenance, and inspection to discuss and forward the state of the art in welding. Within this framework, Commission V is dedicated to quality assurance of welded forms. This paper will describe the current, the past and the expected future activities of Sub-commission VC, ultrasonic based weld inspection.
The best known past activity in Sub-commission VC is the design and implementation of the IIW test block, which is used extensively in industry to set calibration parameters and ultrasonic sensitivity. Currently, the two main areas of focus are the publication of IIW Handbooks in the areas of inspection of austenitic welds and automated ultrasonic inspection (AUT). Austenitic and DMW weld inspection is of interest due to the difficult grain structures that can be encountered, and the resulting problems it causes for ultrasonic inspection. AUT inspection is also of interest due to the large number of companies providing this service. Lastly, future areas of work are discussed, which include re-qualification of the IIW block to provide more uniform properties for setting inspection sensitivity and phased array inspection. |
