Investigation of weld defects in frictionstir welding and fusion welding of aluminium alloys paul kah, richard rajan, jukka martikainen and raimo suoranta abstract transportation industries are obliged to address concerns arising from greater emphasis on energy saving and ecologically sustainable products. Its induced by hydrogen absorbed into the weld via the weld puddle. Often, the crack forms along the axis center of the joint as the two sides pull apart. Weld defects imperfections incomplete root fusion or. Samuel ose311m marmul type of defect api 1104 sp11. Role of welding defects on the failure of subsea carbon steel gas pipeline article pdf available in international journal of engineering and technical research 35. Welder qualified under section 3 of api 1104 or section ix of asme to weld on pipe operating weld defects and radiographic images 3. It illustrates the causes of each of the twenty different weld discontinuities and defects and suggests effective solutions. Api 1104 defectsacceptancecriteria final welding scribd. There was a large group of both member and nonmember participants that attended the meeting. Api 1104 field welding asme section 9 fab shop welding part 192appendix c low stress. This endorsement covers four subject areas in api 1104, material and design, fabrication, inspection, and qualification, including appendix a and b. Problems and incidents on a pipeline sometimes originate during the construction process.
Api 1104, welding of pipelines and related facilities. Lighted telescoping led light illuminates dark area for inspection. Investigation of weld defects in frictionstir welding and. Seven type of welding defect seven type of common weld defects include. Api 1104 defectsacceptancecriteria final free download as excel spreadsheet. The filler material is an uncoated, continuous wire electrode, applied to the. Welding provides a method for joining metal parts with respect to the cost of. Weld defects are often caused by improper technique, parameters or equipment settings. Api publications necessarily address problems of a general nature. Keystone api1104 welder qualification form form w8 rev 0 transcanada in business to deliver welders name print welders id stamp test location, project andor spread no. Api 1104 pipeline welding code 20th or 21st edition api 1104 pipeline welding code 20th or 21st edition aws witt welding inspection technology 2008 aws witw welding insp tech workbook 2008 note.
According to the american society of mechanical engineers asme, causes of welding defects can. Spot weld nugget is generally hidden between two sheets, causing its inspection difficult and expensive. Acceptance criteria of weld defects as per different codes. Pdf multiple defects in welds, when detected, have to be assessed for interaction. This entry was posted in api 1104 exam preparation, aws cwi exam part b practical questions, aws cwi questions and tagged api 1104 cwi test questions, api 1104 question american welding society, api 1104 rt acceptance criteria, api 1104 study guide pdf, api 1104 study material, api 1104 weld test, api 1104 welder qualification test, aws cwi. It is very helpful for you to write down the section numbers and page numbers where you found the answer.
Welding discontinuities and defects hobart institute of. Welding defects, welding imperfections, weldperfect. Weld defects in austenitic stainless steel sheetseffect. Girth welds might contain nonplanar and or planar defects. Kielland semisubmersible drilling rig at the ekofisk oil field, norwegian sector of the north sea. With respect to partic ular circumstances, local, state, and federal laws and regulations. Gauge where the weld size visually appears to be the smallest 2. Get api 1104 welding code 20th edition pdf file for free from our online library pdf file. Pdf development of defect interaction criteria for pipeline girth. Api standard 1104, standard for welding pipelines and related facilities this code book published by the american petroleum institute provides the complete and detailed information needed by welders, inspectors and engineers. Crater cracks causes the welding ended far too abruptly. If i have to weld a 12 main pipe to a 34 fillet weld branch by api 1104, i can qualify the procedure using a 4 main pipe to a 2 fillet weld branch because the diameter isnt a essential variable, but thickness is. The crack begins at a void in the welding crater, caused by the solidi. In addition, it presents an overview of six different kinds of cracks and demonstrates how to prevent cracking and distortion in a.
General guidelines on best practice are given so welders can minimise the risk of. Reproduced by ihs wilh the permission of api under royalty agreement. An investigation was made on the weldability of dp600 steel. Metallographic analysis and tensileshear tests were implemented for weld quality detections.
Welding procedure specifications wps presented by john lucas welding engineer uti corporation. A welding defect is any flaw that compromises the usefulness of a weldment. Weld defects in highfrequency electric resistance welding the two kinds of defects associated with previously defined welding phenomena are cold welds comprised of oxide colonies and penetrators consisting of slag inclusions produced when molten slag is drawn into a gapped zone by h. Many were relaxing in the cinema and the mess hall. Pdf role of welding defects on the failure of subsea. In low alloy steels, as the weld metal structure is more susceptible than. Apiaga joint committee on oil and gas pipeline field welding practices repair welding subcommittee report january 20, 2016 austin, texas the repair welding subcommittee was called to order at 1.
The characteristic features and principal causes of incomplete root fusion and penetration are described. A catalog of api publications and materials is published annually by api, 1220 l street, nw, washington, dc 20005. The objective is to be able to identify and define various types of discontinuities and defects in addition to identifying and determining the common causes of those. When a weld defect appears, its important for welders to have the knowledge to fix the situation as quickly as possible. Weld on ceramic weld metal support at high currents. Overview of weld defects provides a comprehensive introduction to the most common varieties of weld discontinuities and distortion. Eprg guidelines on the assessment of defects in transmission. You measure the perameters just like when setting the original procedure. Keystone api1104 welder qualification form transcanada. A howling 40knot wind was driving rain onto the rig that had just been winched away.
Weld measuring videos improving jobsite efficiency. Welding defects eurotech now inteducing welding defects. Introduction welding is the process of coalescing more than one material part at their surface of contact by the suitable application of pressure or heat or both at the same time. However, transverse weld metal cracks can occur, especially when welding thick section components. Effect of defects on the strength of welds article in journal of engineering design and technology 124. A misalignment of the pieces to be welded radi ogra phi c imz4 ge. Weld defects and how to avoid them welders universe. Api standard 1104, 21st edition is the industry standard for welding practices. Api standard 1104, standard for welding pipelines and. The ss schenectady, an all welded tanker, broke in two whilst lying in dock in 1943. Influences of electrode force, welding current and welding time on welding defects occurrence were discussed. Welding of pipelines and related facilities presents methods for the production of. Magnetic, pickup mirror is held firmly in place at all angles. A 1104 repair procedure consist of making a regular butt weld, then removing weld metal including the bead.
Over 200 of the 212 men aboard were off duty in the accommodation segment of the rig. Api 1104 20th edition section 6 welder qualification 6. Principal causes of this failure were poor design and bad workmanship. Weld quality dependency on welding defects was studied. Porosity, one of the most common mig welding defects, is the result of gas becoming trapped in the weld metal. With root pass welding, quickly move the arc from the. The mechanisms of formation of weld defects in high. Free practice test aws api 1104 awscwi certification. Welding imperfections are classified according to iso 6520 while their acceptable limits are specified in iso 5817 and iso 10042. Dac 825 weld fault comparison kit this weld fault comparison kit is a 3dimensional visual aid designed to facilitates basic training in weld quality, and weld fault terminology by accurately depicting common weld defects in 3dimensional form. Basically id is make a weld, grind out the weld, reweld and tear them apart. Welding defects eurotech now introducing welding defects. Any defect that exceeds the standards of acceptability. Welding defect is any type of flaw in the object which requires welding.
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