NDT Welded Flawed Specimens

NDE TECH:

We would like to introduce you our proud product ndt flawed specimens. Flawed specimens for level ii training, practice and qualification i.e. ASNT-TC-1A, PCN, BS EN ISO 9712, API and others owing to the rich industrial experience, we are involved in manufacturing of a wide assortment of flawed specimen. Offered flawed specimen is used to practical procedure, personnel qualification and Equipment development we, NDE Flaw Technologies manufacturer of flawed specimens in the non-destructive testing and evaluation industry, pioneering many well recognized 'industry standard' flaw manufacture and implanting techniques.

High quality flaws are achieved by a combination of first class workmanship, a unique blend of welding and non-destructive testing skills, plus a full understanding of the product. Flawed specimens contain purposely induced real flaws which are accurately sized and located. Each specimen is supplied with documentation detailing flaw types, sizes and location. Our policy of setting new standards and developing new techniques to improve quality and reliability, assures the highest quality of flaws. The flawed specimens that NDE TECH creates for the global NDE industry are specifically designed with precise flaw placement in a wide variety of specimen geometries and alloy types. NDE TECH specimens are used in various industries to facilitate the education, practice and procedure development of equipment and NDE technicians.

As NDE technology has advanced so has NDE TECH. Our commitment to the NDE industry and to working closely with clients and various NDE organizations has allowed NDE TECH to improve and develop new manufacturing processes and produce new products that meet the technical challenges. High quality flaws are achieved by a combination of NDE TECH's first class workmanship and craft, a unique blend of welding and NDT skills, plus a full understanding of the product. NDE TECH's flawed specimens contain purposely induced real flaws which are accurately sized and located. Each specimen is supplied with documentation detailing flaw types, sizes and location.

This section will discuss some of the more common calibration and reference specimen that are used in ultrasonic inspection. Some of these specimens are shown in the figure above. Be aware that there are other standards available and that specially designed standards may be required for many applications. The information provided here is intended to serve a general introduction to the standards and not to be instruction on the proper use of the standards.

Development and Production of Welded Flaw Specimens for Non-Destructive Testing

ABSTRACT:

It is mandatory that the personnel who performs non-destructive testing have been trained and is certified. This is the only way to ensure valid and reliable results. The present paper addresses the development Of welding procedures for systematic production of flawed specimens to be used for training and certification of ndt personnel. Another very important aspect in executing ndt is the proper equipment calibration. For that purpose calibration standards are used. The present paper also addresses the development of a database of ndt Calibration blocks that will be used as a query.

Front Matter:

The non-destructive testing (ndt) are techniques to examine objects, materials or systems without damaging them and, therefore, without affecting their future usefulness. These techniques are extremely valuable because, as they do not permanently change the state of the component, they allow to save time and money in evaluation, in problem solving, in prevention of occurrence of failures and product research. They are widely used in many different industries like oil/petrochemical, chemical, electromechanical, aeronautic, aerospace, among others. The conventional ndt techniques include Penetrant Testing (PT), Magnetic Testing (MT), Radiography Testing (RT), Ultrasonic Testing (UT) and Eddy Current Testing (ET).

Welding and Its Defects in Industry:

Welding is a critical technique for joining materials in many industries, such as the construction industry, petroleum, petrochemical, aeronautics, manufacturing processes, among others. It is an efficient, economic and reliable process. However, during the process of welding different defects may occur, such as porosity, inclusions, lack of fusion, deficits or excesses of penetration, cracks, etc., all of which can be due to poor gas protection, poor welding technique, unclean surfaces, wrong welding parameters, etc. These defects can cause failures and accidents, endangering the normal functioning of parts and components, and risking people¡¯s lives. It is necessary to do the inspection of welds to assure an adequate control of the manufacturing process. Non-destructive testing is the most important technique used for this purpose.

Surface Welding Defects:

Intentional weld defect or flaw specimens can be required for Training purposes, developing new non- destructive testing Techniques, qualifying non-destructive testing procedures, obtaining Mechanical property data and in support of safety cases. The single Most important criterion in producing defects or imperfections is that They must accurately simulate flaws which can occur in welded Components and structures. For this reason, in certain applications, Saw cuts or machined slots which are more easily detected may not Be considered acceptable as planar imperfections/defects for the Purpose of NDT training or validation. Therefore, NDE TECH has Developed techniques for producing realistic imperfections/defects And, in the case of cracks, the desired morphology, including Roughness, angles of tilt and skew to the surface.

Sub-Surface Welding Defects:

Intentional weld defect or flaw specimens can be required for non-destructive testing (NDT) Operator training and validation, to develop validated NDT procedures or new NDT techniques, to Obtain mechanical property data and in support of safety cases. The single most important criterion In producing defects or imperfections is that they must accurately simulate flaws which can occur in Welded components and structures. In particular, when summarizing the work carried out within the PISC project series (Project for the Inspection of Steel Components), Cruzan et al [1] concluded That the NDT procedure has to be validated and tested on structures containing defects that, not Being necessarily real ones, still do induce the real physical phenomena that the inspection Techniques must be able to handle. Cruzan et al also stated that the use of very artificial Discontinuities (side-drilled holes, SDH or flat-bottomed-holes, FBH) to demonstrate the capabilities Of NDT techniques often results in optimistic statements and hazardous use of the technique on Structures containing real defects. When comparing the use of welded joints with real or artificial Realistic flaws (see definitions in Section 2), Cruzan Listed the following advantages for the latter.




Types of major realistic defects:

  • Lack of Side-Wall Fusion
  • Lack of Root Fusion
  • Slag Inclusion
  • Solidification Cracking
  • Crater Cracks
  • Weld Metal Transverse Cracking
  • Porosity
  • Heat affected Zone (HAZ) cracking
  • Brittle fracture and fatigue cracks


Manufacture of defective weld and final inspection:

Once the qualification procedure is complete and it is has been demonstrated that all required defect types can be deposited within the target tolerances on size, the defective welds are manufactured. Following completion of the welds, UT inspection is normally carried out to verify that all required defects have been inserted and are detectable. Any additional indication which does not correspond to any of the required defects is also recorded.

Quality assurance system:

NDE TECH use a documented quality assurance system that demonstrates that the examination test specimens have been fabricated to the requirements of this guide. This should include fabrication records of the test specimens.

NDT flaw characteristics:

NDE TECH shall demonstrate, by practical trials, their ability to accurately evaluate flaws from their appearance, indication or response.

Evidence/trials:

NDE TECH shall demonstrate that the flaw dimensions given in this guide can be achieved and maintained. For planar flaws a macrosection should be used to determine height and width on at least two samples. For volumetric flaws, macrosections and radiography should be used to measure the flaw length, height and depth for at least two samples. Samples shall be witnessed and approved by a second or third party.

Trials for each flaw type and each welding technician shall be carried out to evaluate the dimensions whenever there is a change of the fabrication process or welding technician.

Geometric Conditions:

Geometric conditions such as a counter bore, mismatch, etc. should not affect the detection, sizing and evaluation of the intended flaws.

Surface Condition And Appearance:

The test specimen surface condition shall not interfere or influence the intended examination results.

Dimensional Tolerances:

The nominal size for a given type of examination test specimen, regarding length, diameter and thickness should meet the following dimensions:

  • Test specimen length/width - 10%
  • Test specimen diameter - 10%
  • Test specimen thickness - 10%



Selection Of Raw Materials Prior To The Fabrication Of Test Specimens:

  • Materials forming a permanent part of a qualification test specimen must not contain any flaws that will interfere with the examination of the test specimen. Refer to the acceptance criteria for unintended flaws (refer to clause 14).
  • Materials, where requested, must meet the requirements of the end user.
  • Materials used for the ultrasonic specimens shall not have a transfer correction exceeding 6 dB.
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