Radiography Test Question Answers NDT CSWIP Course RT Welding. Welding Joints and Discontinuities. Sufficient bonding of enclosures at every seam and discontinuity must be created to have a homogenous conductive surface. No, by definition a defect is always rejectable. This term designates rejectability. ... A penetrameter is not an indicator or gauge to measure the size of a discontinuity or the minimum detectable flaw size. A depression in the weld face at the termination of a weld bead. Individual discontinuity: - Area ≤ 1000mm 2; Clusters of discontinuities: - 15 in the most populated 1m x 1m square (individual discontinuities < 100mm 2 are ignored) It is also recommended that edge discontinuity class E1 should be specified for the edges of plates where corner welds will be made on to the surface of such plates. In addition, the presentation will offer advice on determining Note: Arc strikes may develop stress risers, which could lead to cracking. Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) and metal active gas (MAG) is a welding process in which an electric arc forms between a consumable MIG wire electrode and the workpiece metal(s), which heats the workpiece metal(s), causing them to fuse (melt and join). An occasional improper condition can render a manufactured welded structure imperfect. Presentation on Radiography Testing By Abhishek A V abhishek.agyarapu@gmail.com 2. Radiography Testing Presentation 1. Are there any acceptable weld defects? The materials and weld details should be well define prior to simulations. Welding Definition By welding321 Posted on March 7, 2021 March 8, 2021 Welding is a process of joining two or more metals similar or not similar to the metal melt by heating […] and is a valuable indication of weld quality. Discontinuity : An interruption of the typical structure of a material, such as a lack of homogeneity in its mechanical, metallurgical, or physical characteristics. Laminations ‘Base Metal Discontinuity *May require repair prior to welding ‘Formed during the milling process 12/03/2006 For all your welding and Quality needs contact djhelIiweId@yahoo. welding terms glossary abrasive – Slag used for cleaning or surface roughening. Preventive Action. These may be defined further as square, bevel or special groove, fillet, and simple (if they are welded from one side only) or double, from both sides. Set-in Nozzle (Fig. An interruption of the typical structure of a material, such as a lack of homogeneity in its mechanical or metallurgical, or physical characteristics. Ref: ANSI/AWS A3.0-10 – Standard Welding Terms and Definitions The other types of discontinuities are … Definition A discontinuity consisting of any localized re-melted metal, heat effected metal, or change in surface profile of a finished weld or base mate-rial surface resulting from an electrical arc. However, only discontinuities that exceed the tolerance limit should be considered as welding defects.. discontinuity definition: 1. the fact that something changes or stops rather than continuing in the same way; a change or…. The castings used to produce the standard radiographs have been destructively analyzed to confirm the size and type of discontinuities present. ... and the one in which the lack of fusion shows no discontinuity in the material since it is a structural defect and thus cannot be detected by non-destructive methods. Discontinuities are, by definition, acceptable. The metal particles expelled during fusion welding that do not form a part of the weld. Crater - ... - Arc welding process which uses a spooled, tubular filler metal electrode consumable enveloping flux. Removable discontinuities can be "fixed" by re-defining the function. Productivity benefits of continuous electrode welding are generally recognized, but there are also some published data (3–5) showing technical benefits arising from the elimination of the operational discontinuity of the stick electrode and the adoption of the continuous electrode processes, as considered below. definition of - senses, usage, synonyms, thesaurus. Inspection Tools 62. 3): Nozzle is projected inside the vessel surface. This is the source of a relevant indication. The convex surface of specimen should not show any open discontinuity of more than 3 mm in any direction. A welding process that produces coalescence of metals with molten slag that melts the filler metal and the surfaces of the workpieces. WELDABILITY is the feasibility of welding particular metal or alloy. Slag inclusions are nonmetallic particles trapped in the weld metal or at the weld interface. Any discontinuity (or irregularity) in the weld metal, which exceeds the applicable code limit, is termed as a WELD DEFECT (or Welding Defect). Certified welding inspector. com Here is the definition of a "Gross Structural Discontinuity" taken directly from 2008 Edition ASME Section III,Division 1,Subsection NB, Class 1 Components. Weld discontinuities can be defined as 'an interruption of the typical structure of a weld, such as a lack of homogeneity in the mechanical, metallurgical or physical characteristics of the weld.' Annex K discontinuity. ... By monitoring the welding process an experienced supervisor can find the formation of lack of fusion. The Journal of Arthroplasty brings together the clinical and scientific foundations for joint replacement of the hip and knee. cone weld is also an ISI weld solely due to the weld being classified as a gross structural discontinuity since this weld is a cylindrical shell-to-conical shell junction. The upper steam drum shell-to-transition cone weld has both a higher stress intensity range and fatigue usage factor than the closure girth weld. These discontinuities occur in most metals welded by the process, including aluminum and stainless steels. The book includes a glossary of welding terms, welding inspector responsibilities, identification and definition of weld discontinuities and defects, and common causes of discontinuities. Welding Discontinuities Evaluation of the discontinuity will determine if the discontinuity is a defect or an acceptable condition: Undercut - A groove melted into the base metal adjacent to the weld toe or weld root and left unfilled by weld metal. Active Flux – Submerged-arc welding flux from which the amount of elements deposited in the weld metal is dependent upon welding conditions, primarily arc voltage. This TIG weld (Figure 2A) was created with the machine’s polarity set on direct current electrode negative (DCEN). A huge list of welding terms! Slag inclusions result from faulty welding technique, improper access to the joint, or both. - A fracture-type discontinuity characterized by a sharp tip and high ratio to length and width to opening displacement. The following are welding related theory & application terms and definitions listed in alphbetical order A to Z . Weld Inspector Responsibilities Related to Discontinuities and Defects 2. In such cases, welding should be considered. Discontinuities can be classified as jump, infinite, removable, endpoint, or mixed. Fillet Weld Size - For equal leg fillet welds, the leg lengths of the largest isosceles right triangle that can be inscribed within the fillet weld cross section. AS WELDED: The condition of weld metal, welded joints, and weldments after welding and prior to any subsequent thermal, mechanical, or chemical treatments. When there is a sudden change in the geometry of the body due to cracks, sharp corners, holes and decrease in the cross section area, then there is an increase in the localised stress near these cracks, sharp corners, holes, and decreased cross section area. Only repair defects. A discontinuity is not necessarily a defect. Repair is thereforeunnecessary and not cost effective. How to use weld in a sentence. Online Dictionaries: Definition of Options|Tips Ramesh Singh, in Applied Welding Engineering (Second Edition), 2016. defect. Galling is a form of wear caused by adhesion between sliding surfaces. ARC WELDING that used an electric arc to provide heat. Weld Flaws A weld flaw is any indication on a weld that can compromise the quality of the weld. When a material galls, some of it is pulled with the contacting surface, especially if there is a large amount of force compressing the surfaces together. It is a simple, 2.4 Experience and Training. Jump Discontinuity. WELDING is a process used to joint Metals by the application of heat, pressure or a combination of both. Infinite Discontinuity. 61. Active Fluxes – Active fluxes produce changes in weld metal chemistry when welding is changed.Active fluxes are restricted to single or minimal multi-pass welding. Discontinuity is an interruption in the typical physical structure of a material that sharply changes its properties.Thus, the simple variation of properties does not characterize a discontinuity. Definition: The protrusion of weld metal beyond the weld toe or weld root Main Causes: (1) Too low welding amperage (2) Too slow electrode manipulation (3) Too short arc length, or too low arc voltage (4) Electrode travel and work angles are inappropriate. One of the most useful characteristics of ultrasonic testing is its ability to determine the exact position of a discontinuity in a weld. 1. NB-3213.2 Gross Structural Discontinuity. Magnetic particle Inspection (MPI) is a non-distructive testing (NDT) process for detecting surface and shallow subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys.The process puts a magnetic field into the part. That is, for example, it probably is NOT a good idea to look at the Marketing System as a stand alone implementation, or the Manufacturing System as a stand-alone system, or the Accounting System as a stand-alone system, etc., etc. The following discontinuities are unique to the TIG welding process. Visual examination reveals surface flaws, and (3) satisfy the need of the inspection. The piece can be magnetized by direct or indirect magnetization. Problem Definition: Consider the Nozzle Shell Junction problem. Processing discontinuities relate to manufacturing processes. Very short wavelength radiation produced when electrons travelling at high speeds collide with matter is called: a transform X-ray energy into visible or ultraviolet light to which a photographic emulsion is sensitive. Weld definition is – to become or be capable of being welded. The process is initiated by an arc that heats the slag. Here the nozzle is welded to the cylinder, refer Figure 1. Nondestructive testing (NDT) is the process of inspecting, testing, or evaluating materials, components or assemblies for discontinuities, or differences in characteristics without destroying the serviceability of the part or system. It is only when a discontinuity… Weld discontinuities include porosity, slag inclusions, … Defect A discontinuity that by nature or accumulated effect render a part or product unable to meet minimum applicable acceptance standards or specifications. The shielding gas protects against discontinuity, which could weaken the weld. Liquid penetrant inspection is used to detect any surface-connected discontinuities such as cracks from fatigue, quenching, and grinding, as well as fractures, porosity, incomplete fusion, and flaws in joints. Continuity at a Point. The following is a brief description of the most common discontinuity types included in existing reference radiograph documents (in graded types or … Stress concentration is the accumulation of stress in a body due to sudden change in its geometry. Machining, extruding, rolling, welding, heat treating, and plating all are examples of processing discontinuities. Subsurface discontinuities not readily seen on the surface are detected during the finer processing of … This testing method requires a high level of operator training and competence and is dependant on the establishment and application of suitable testing procedures. DEFINITION OF WELDING. Again, depending on the welding and positioning of the nozzles two types of nozzles are widely known. Lamination effects can be reduced by joint design: 12/03/2006 For all your welding and Quality needs contact djheIIiweId@yahoo. appearance of the weld, HAZ, and base metal were observed through the use of the confocal scanning laser microscope in order to categorize the presence of surface discontinuities and microcracks according to weld process and material type. Flux cored arc welding, also known as FCAW, uses a wire that is not solid, but instead has a core that contains the shielding gases needed to protect the weld from contaminants. ESW – Electroslag Welding. How to use discontinuity in a sentence. As you can see, the weld did not break through the aluminum oxide layer. Definition: an imperfection or discontinuity that may be detectable by non-destructive testing and is not necessarily rejectable. Weld Root Heat A˚ected Zone Reinforcement Toe Leg Joint Root Weld Root Theoretical Throat A˚ected Zone Heat Leg Face TERMS & DEFINITIONS Toe – The junction of the weld face and the base metal. Common weld types are butt, T, corner, lap, and edge. This is what D1.1 says about spatter and discontinuities: Annex K spatter. Fundamentals of Visual tools should be used that: (1) comply with the project re- Examination quirements, (2) are adequate for the intended accuracy, 3.1 General. Discontinuity definition is - lack of continuity or cohesion. as x approaches a, the limit for f (x) equals f (a) when a function can be redefined and it fills in the hole. Discontinuities near the surface, such as weld undercut, are more difficult for time of flight diffraction to detect. CWI. After welding, visual inspection can detect a variety of surface flaws, including cracks, porosity and unfilled craters, regardless of subsequent inspection procedures. Learn more. All welds contain features or discontinuities. Meshing: Quadratic (second order) fine and … Welding Defects are excessive conditions, outside the acceptance limits of deviations, which risks to compromise the stability or the functionality of the welded structure. Leg – The distance from the joint root to the toe of the weld. Discontinuities are, by definition, acceptable. This workbook provides an explanation of welding discontinuities and defects in relation to welding procedure variables and will benefit welding students and professionals. when x approaches a from the positive side for f (x) and x appr…. There should be metal-to-metal contact done through welding… In other words, when the inspection or test is completed the part can still be used. Prior to energizing welding equipment, re- Then the tension forces are required to be transferred from one bar to the other bar at the location of discontinuity of the bar. Repair is therefore unnecessary and not cost effective. 2 Definition of lack of fusion. Discontinuity-the same type of abnormality as a defect, but to a lesser degree that might be considered harmless and acceptable. A weld flaw can be accepted or rejected depending on three factors: type, size and location of the flaw/discontinuity. Removable discontinuities are characterized by the fact that the limit exists. Sharp notches in joint boundaries or between weld passes promote slag entrapment. Inspection Tools Measuring Weld Sizes. The definition of the two depends on the bandwidth of the signal on the receiver, termed as the resolution bandwidth. Content: • Front Matter • Glossary of Welding Terms • Table of Contents 1. Acceptable Weld – A weld that meets the applicable requirements Actual Throat – The shortest distance between the weld root and the face of a fillet weld. com 63. The pressure vessel opening diameter in the shell/head coincides with the outer diameter of the neck. 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