Welding Essay Example
- Category:Engineering and Construction
- Document type:Assignment
There are five types of joints in welding which varies from one another in a number of ways. These joints include; butt joints, it is also known as square-groove. It is one of the easiest welds to use. This joint involves two flat pieces and parallel to each other, this method is commonly used in joining pipes, valves, and flanges. Corner joints, this is a joint in which two metals are located together at a right angle forming an L. The metals are joined together to form a corner, edge joints is a groove kind of a weld. Metallic materials are placed side by side and then welding is done on the same edge. The lap joint is a joint where two metallic pieces are positioned atop each other as they overlap one another at a given distance at the edges. This type of joint commonly involves joining metals of different thicknesses. Lastly, tee joint also referred to as fillet weld is formed when two pieces intersecting at a right angle are joined together, where the middle of one piece intersect the edge of the other (Lacki, & Adamus, 2011).
In order to achieve strong welds, it is important that preparation on the material take place. A weak joint is likely to be formed in case the materials are not well prepared. The metals which are well prepared will be free from stress that arises from contraction and expansion of the materials as a result of heating and cooling. The main reason as to why materials should be prepared is that the joints will be strong enough. They will also be free from stress that may result from contraction and expansion of the materials as a result of cooling and heating. In joint preparation, the basic step is to ensure that all the impurities are removed. This can be achieved through rust, oxide and mill scale removal.
The common welding process that is mostly used are; manual metal arc welding, metal active gas welding, stud welding and submerged arc welding. Attaching of shear connectors is done by using stud welding. And an individual has to make the right choice of the process to use depending on; the situation, position, the fit-up, access, the cost as well as steel composition.
There are many ways of preparing a butt join. Some of these ways include; cutting, sheathing, and chipping among other ways. In preparation of this joint, a standard grinder has to be used. For a light metal with measurement ranging from 3/8 to ½ an inch a single U-groove or V-groove joint is used.
In the images above, B indicates the double V joint. This type of joint should be used when the plate’s measurement ranges from 0.5 up to 2 inches. In case one wish to prepare a joint of plates which are of the dimensions ranging between ¾ inches and above it is advisable to use the double U-joint as shown by the image D. The main reason of preparing the U and V shape on both sides is that: it will make it easier for welding. Secondly, the level of distortion will be reduced and finally, preparing both sides will ensure that the welds will be of higher quality in relation to when it was only prepared on one side (Nandan et al. 2008)
Preparation of the corner joints
Corner joints take different forms such as; closed/flush, half open, or fully open. These types of joints can be clearly indicated in the image.
Image A; it indicates the corner joint. This type of joint is referred to as fillet corner joint. Mostly used in boxes and tank fabrication.
Image B; indicates a closed corner joint. This is a type of joint that is common in the sheet that is of gauge 20 or less. During preparation of this joint, no filter or very little of the filter will be used in case one uses the process of oxy-acetylene. This is because the edges are likely to meltdown and as a result, they will overlap. The lapped plate will have to be beveled using the V or U groove in case one uses heavy metal in the preparation of closed corner joint. A small bead will be used to complete this joint in case of stick welding.
In the case of fine metals of 12 gauges and above, a half corner weld joint would be fine. A half open corner joint is considered where the strength of the joint is not an important factor to consider or weld need to be done on one side.
Image C; this image indicates an open corner joint. It is one of the strongest corner joints one can make. This type of joint requires the materials used to be strong enough such as heavy and thicker sheet metal. The corner is designed in such a way that; the edges of the plates will have to melt and it then adds some filler materials on the corners.
Image D; this image indicates the corner joint common in heavy materials. Welding is done on both sides of the material. Just like the fillet weld, this type of joint has a bead to reinforce it.
This type of joint can be classified as one among the weak joints. This type of a joint is common among plate reinforcement, mufflers, and sheets among other materials.
Image A; it indicates how two heavy plates have been welded together. This is a one edge joint weld where the two plates have been joined at the top. A filler material has been added so that it can melt fusing the two materials together. The filler materials are used for reinforcement of the materials.
Image B; this is a joint that requires little preparation. In this type of joint, no filler material is required. This is because the edges will have to melt and they fuse to one another (Petrov, 2005).
Image C; the edges of the plates have to be beveled. Beveling the edges assures a proper fusion of the material. Filler materials are of great importance so that welds can penetrate and fusion occurs on the wall’s sides.
The base metal will overlap each other forming a joint. These types of joints could be of different forms. For instance fillet weld. This can also be termed as a one-sided weld. This is indicated by image A. The form is both sided weld. This form of the weld is very strong since it has been welded on both sides. Image B indicates this type of a joint. Finally is the offset lap joint. This is a strong weld and is stronger than the single lap joint. However, preparation of this type of joint is a bit challenging in terms of penetration and makes fusion challenging too.
This type of joint occurs when two plates are joined a right angle but not at the edges forming a T shape. In preparation for this type of a joint, the edges are beveled, both sides of the plates are tack welded, a bead is laid on both sides. This can be indicated in the image on the right. However, as indicated by the left image, there are instances where welding is done on one side.
Image A; indicates a type of tee joint that requires no preparation. Both metal plates are cleaned and then joined together.
Image B; it indicates a single joint. This type of joint is common on heavy materials. Welding is done on both sides of the plates making it strong enough.
Image C; beveling of the material is done on both sides. Welding is done on both sides of the material. This is done on both sides of the plates. In this type of joint, it requires that thick materials to be used.
Image D; it indicates a single J joint. Welding is done on both sides of the material. Beveling is done on one side of the joint.
Lastly, image E indicates a double J joint. This is a joint prepared for the thicker and heavier materials.
Shield metal arc welding (SMAW)
i. It is highly versatile in that it has a number of applications.
ii. It is a portable equipment
iii. Relatively low cost
It can be adjusted according to the confinement.
1) Time consuming as it is regularly stopped/ started in change of electrodes.
2) High wastage of metals and electrode stubs.
There is a low deposition rate
Submerged arc welding (SAW)
i. High-quality welds
ii. Low welding fumes and radiations
iii. Suited for welding low alloy, alloy steels, and carbon
High rate of metal deposition
1) Only suitable for either flat or horizontal position
2) High skills are required in order to ensure that a correct alignment of electrodes is maintained.
Weld pool and the tip are below the metallic flux cover
Lacki, P. and Adamus, K., 2011. Numerical simulation of the electron beam welding process. Computers & Structures, 89(11), pp.977-985.
Nandan, R., DebRoy, T. and Bhadeshia, H.K.D.H., 2008. Recent advances in friction-stir welding–process, weldment structure and properties. Progress in Materials Science, 53(6), pp.980-1023.
Petrov, P.I., 2005, May. Electron Beam Welding Process. In 7th International Conference on Trends in Welding Research.
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