Lack of fusion in the root. This porosity can easily be avoided by avoiding contact with the wet environment during welding and making sure that the weld pool is properly shielded with either flux, gas shielding, or both. Slag Inclusion. Undercutting. In the welding process which uses shielding gas, the flow rate too high so can make turbulence. 2. 3. Find welding defect stock images in HD and millions of other royalty-free stock photos, illustrations and vectors in the Shutterstock collection. Now, this non-uniform phenomenon is what we call as discontinuity. This typically takes two forms, either hot or cold cracking. The Tungsten electrode is in contact with the weld pool during the welding process. 1. If the welder is unaware and somehow make a mistake, it will result in the non-uniform weld metal. Increasing the plate angle and using proper gas shielding. Remove rust or oil from the surface and use a proper technique. It’s a … Complete visual inspection is done and any surface breaking or defect shall be repaired as per approved procedure. In hot crack, cracks happen because of the pre-existing contaminant like; sulfur and phosphorus inside the base metal. Use of improper size of the electrode 4. eval(ez_write_tag([[728,90],'theweldingmaster_com-box-3','ezslot_3',151,'0','0']));Welding Defects can be defined as the irregularities formed in the given weld metal due to wrong welding process or incorrect welding patterns, etc. 3. When the weld metal is hot, the hydrogen in the environment might enter the metal by the mean of diffusion. 2. These types of imperfection are more likely in consumable electrode processes (MIG, MAG, FCAW, MMA and SAW) where the weld metal is 'automatically' deposited as the arc consumes the electrode wire or rod. Welding cracks can be present at the surface, inside of the weld material or at the heat affected zones. Run a gloved hand over the distressed areas looking for places where it catches to identify protrusions. This hydrogen atom will mostly reside in the HAZ (Heat-Affected Zone) where the crystalline is most susceptible due to its coarseness. Undercutting is a groove that develops in the base metal near the toe or root of the weld. Using a proper technique for welding. Increasing the joint angle. The trapped slag replaces the supposed filler weld metal with a chunk of Manganese Oxide (may vary) that when you chipped it off will leave the hole gaped, making it good for nothing. 2. The undercut is one of the classics, along with slag inclusion and porosity, which occur most in welding. This is the most unwanted defect of all the other welding defects. Spatter Preheating the weld and reducing the cooling speed joint helps in reducing crack. If you think so, know that you’re not wrong. Using proper materials for welding. 3. This article will give you a clear definition of discontinuity itself that will surely help you as a welder. Spattering. Hence the name cold crack. Adjust the welding speed so that the slag and weld pool do not mix with each other. Your email address will not be published. Spatters can be removed by being grinded or struck using a hammer. Incomplete fusion: In this types of welding defect gap is not totally filled by molten metal. It occurs when the crater is not filled before the arc is broken, which causes the outer edges to cool faster than the crater. However, other problems, known as discontinuities, may be minute enough to escape the heavy hand of justice. 2. Craters. 4. Clean the weld edges and remove the slags of previous weld layers It seems like there’s a force of nature that intervenes to turn things into disorder or chaos. Defects occur due to the melting of tungsten into the weld metal. Incorrect welding preparation, start from incorrect tack weld. An ideal weld or good weld should be such that adequate fusion exists between the filler metal and edge preparation together with good penetration. Before to use, the electrode must be drying in the oven. Using a proper torch angle may reduce the stress on the metal The various types of external defects with their causes and remedies are listed below: 1. Either your tire blew out or transmission malfunction or even external disturbance like crashes and getting a ticket from patrolling police officer. 1. 4. External Welding Defects. Less deposition of the weld metal This page describes welding defects that impair welding quality such as pits, undercut, overlap, insufficient reinforcement, bead cracking, arc strike, bead meandering, bent bead and remaining groove. The various thing can cause slag inclusion, dirty weld surface, and a relatively low welding parameter being used is supposed to be the primary cause. … Using the right polarity and according to the conditions of the welding. It is also called as incomplete penetration defect. Incompletely filled groove or Incomplete penetration. Don’t let the hot electrode come into contact with the filler metal. The welding consumables shall also be checked during welding. Welding preparation should be correct, you can look at the welding procedure to set the correct size of the root gap and root face. While weld spatter is common for processes that rely on a separate substance to act as … 2. Fig. 3. It’s a situation when the slag – a protective layer that supposed to resurface and protect the molten weld pool – is trapped under the geometry of the weld itself. Arc Strike is a type of welding defects occurring in the material and adjacent to the weld metal. 1. It reduces the fatigue strength of the joint. Some crack can happen during a non-welding process such as lamellar tearing. Improper welding technique. 1. 1. The word. Defects of this type can occur for a number of reasons, including the use of incorrect materials during the process, or the failure of the welders involved to perform the necessary tasks completely and efficiently. 1. 3. Increased welding currents. 2. Slag is formed if the welding current density is very small, as it does not provide the required amount of heat for melting the metal surface. 4. Improper welding technique. Welding defects can be classified into two types as external and internal defects:eval(ez_write_tag([[468,60],'theweldingmaster_com-medrectangle-3','ezslot_7',152,'0','0'])); 1. 2. Unproper bead position. Welding Standards and TrainingFor a little under 2 years McClain E-Z Pack hired JimDavis, a recently retired welding instructor, to workwith me on a part-time basis to help the weldersimprove weld quality. We can surely do our best to avoid making mistakes so frequently if we strive. Provides a place to put electrode holder. When inspecting for defects, pay close attention to welded joints, cuts, punctures and scoring. The various types of external defects with their causes and remedies are listed below: This is the most unwanted defect of all the other welding defects. Crater cracks. Welding defects always appear as a result of specific physical and chemical characteristics of an Mg alloy, mainly including oxidation and evaporation, overheated coarse grains, heat cracks, pores and thermal stress, and so on. More deposition of the weld metal. 4. By using large electrodes this defect may occur. Cold Crack – This type of crack occurs at the end of the welding process where the temperature is quite low. 5. Therefore a complete repair procedure should be done at once when the crack is detected by any examination method (radiography, liquid penetrant, and magnetic particle). In this condition the weld metal rolls and forms an angle less than 90 degrees. These defects occur only when the weld is too small to withstand the service stresses involved. (Also read How to write a welding procedure specification – WPS) After welding: After complete welding, identification number is punched near joint. When the angle of the joint is too low. Poor ductility of the given base metal. Welding Defects – Do you know that no matter how you try to keep things in order, but in the end, a mistake will still happen?