Bilgisayar Destekli Ark Kaynak Maliyeti Hesaplanması

Abstract

İnsanoğlunun yaşantısını baştan aşağıya değiştiren ve her alanda kullanılarak harikalar yaratan "mikroçip" ler 20' nci yüzyılın en büyük yeniliği olarak tarihe geçecek. Sosyal güvenlik numarası, telefon numarası, kredi kartı numarası, kandaki kollestrol oranı, parasal işlemlerin onay numarası derken, hayatın her alanı " rakamlar" tarafından kontrol edilir hale geldi. Modern yaşantıda her şey bir rakamın içine konulacak kadar küçülüyor. Artık bir atomun çapının ölçüsünden bir kromozonun ağırlığına, lazer ışınlarının dalga uzunluğundan, bir boksörün gösterdiği reaksiyona kadar herşey rakamlarla önümüze konuluyor. Yaklaşık 40 yıl önce icad edilen bir tırnak büyüklüğündeki " mikroçip" bir kent kadar karışık ve bir nükleer reaktörden daha güçlü olabiliyor. Kısaca yukarıda anlatılan bilgisayar ile maliyeti hesaplanacak olan; 1930' iu yılların başlarında geliştirilmeye başlanan ark kaynak yöntemi, 15 yıl içinde en üstün birleştirme yöntemi haline gelerek çok büyük önem kazanmış ve bu önemini günümüze kadar arttırarak devam ettirmiştir. Bugün sualtında yapılan kaynaktan uzayda yapılan kaynağa kadar birçok alanda en gelişmiş tekniklerle kullanılan kaynak yöntemleri otomatize olmanın ötesinde özellikle otomotiv endüstrisinde artık robot teknolojisini kullanmaya başlamışlardır. Kaynak, diğer imalat yöntemlerine göre ağırlık, zaman, işçilik vb. gibi birçok bakımdan avantaj sağlarken maliyet büyük ölçüde azalır. Bütün imalat yöntemlerinde olduğu gibi kaynakta da maliyet hesabı önemli bir unsurdur. Özellikle büyük ve karışık konstrüksiyonlarda bu hesabın yapılması uzun ve yorucu bir iştir. Ancak 20. Yüzyılda gelişen bilgisayar teknolojisi bu işlemi asgariye indirmiş, önceden günlerce üzerinde çalışılan maliyet hesapları artık dakikalarla ölçülebilecek sürelerde ortaya çıkarılmaya başlanmıştır. Doğru ve kesin maliyet hesabı için bütün girdilerin birleştirilmesi, programa yüklenmesi ve fiyatların güncelleştirilmiş olması büyük önem taşımaktadır. Maliyet hesabının iyi yapılması önceden önümüzü görmemizi sağlaması yanında bilgisayar desteğiyle karışık ve büyük konstrüksiyonlarda uzun zaman alan bu işlemin çok kısa bir sürede bitmesi yanında zaman tasarrufu da sağlanacaktır.

Computer aided Cost Astimation of Arc Welding With the name of " Computer aided Cost Astimation of Arc Welding " master study, I tried to be helpful to solve welding cost calculations during project period with calculate Cost of Arc Welding by Computer which is best equipment in our time period. Welding procedures; after a joint design has been selected and the edges of the members have been prepared. The first step in welding is to place the part in position and to adjust them for optimum fit-up. Tackwelds are frequently used to hold the fixed positions. For welds in joints that require ore than a single pass, welding is initiated by depositing a narrow bead at the bottom of joint. Welding then proceeds by depositing consequting beads over the original bead until the desired dimension of the weld is obtained. The weld should be cleaned following each pass in multiple - pass welding. Procedures vart considerably, depending on joint design, position of joint, thickness of sections being welded, and variation of thivkness among sections being welded. The cost of welding is an important factor to consider when selecting a welding procces for an application. Factors such as deposition rates, welding speed, joint preperations time, operator factors, and welding material costs must be compared to properly choose a welding process. Shilded metal - arc welding is a manual arc welding process in which the heat for welding is generated by an arc established between a flux-covered consumable electrode and work. The electrode tip, weld pudle, arc, and adjasend areas of the workpiece are protected from atmospheric contamination by a gaseous shield obtained from combustion and decombustion of the flux covering. Additional shielding is provided for the molten metal in the weld puddle by a covering of molten flux (slag). Filler metal is supplied by the core of the consumable electrode and, with certain electrodes, from metal powder mixed with the electrode covering. Shielded metal-arc welding is often referred to as arc welding with stick electrodes, and as manual arc welding. The initial investment for the equipment can vary considerably depending on the size and complexity of the equipment used. The equipment used is often basically the same as for gas metal arc welding. Because of the higher current levels used in flux cored arc welding larger power sources may be needed. With the self - shielding electrode wires, a gas shielding system is not needed, which simplifies and reduces the overall cost of the equipment. In some cases where gas metal arc welding equipment is available, a change to flux cored arc welding would require almost no new equipment. The equipment for semiautomatic welding is much less expensive than equipment for automatic welding. Many cost studies made to compare shielded metal - ere with submerged - arc welding and gas metal - arc welding have shown that, when welding conditions (mainly welding position, accessibility, and the amount of welding done wihout changing classes or sizes of electrodes) are favorable, shielded metal arc welding is the most costly of the three processes. Cost studies have also shown thay if shielded metal - arc welding is used in production and electrodes of the same class and size are used for more than half the welding time, the use of a process that utilizes a continuously fed electrode should be considered. Conversely, in applications where welding must be done in a variety of positions, or some areas are difficult to reach, or where specifications require frequent changes in class and size of electrode. Flux -cored arc welding is aprocess in which the heat for weldinh is produced by an arc between a tubular consumable electrode wire and the work metal, with shielding provided by gas evolved during combustion and decombustion of a flux contained within the tubular electrode wire, or by the flux gas plus an auxiliary shielding gas. Submerged-arc welding is an arc welding process in which the heat for welding is supplied by an arc (or arcs) developed between a bare - metal, consumable electrode ( or electrodes) and a workpiece. The arc is shielded by a layer of granular and fusible flux, which blankets the molten weld metal and the base metal near joint, and protects the molten weld metal from atmospheric contamination. Gas - metal arc welding (often called MIG - MAG welding) is an arc welding process in which the heat for welding is generated by an arc between a consumable electrode and the work metal. Today, Gas Metal Arc Welding (GMAW) is one of the most popular electric arc processes where the heat necessary for the welding s supplied by an arc struck between the work piece and the consumable wire electrode which is continuously fed forward to replace the metal that is melted. Wire in this process serves both as electrode and as the filler metal. Gas Metal Arc welding utilizes a gas mixture in order to shield the arc and the weld pool from the detrimental effects of the oxygen and nitrogen in the atmosphere. XI The torch which is often called as gun, delivers borh the shielding gas and the electrode filler wire to the weld at preset controlled sped and quantity. This is maintained in constant lenghht by the power source, the travel and guidiance of the torch can be manual ( semiautomatic) or by machine (automatic) The possibility of using an inert gas to shield the weldinarc and the molten pool from the detrimental effects of the atmosphere was first investigated in the 1 920's. New improwments on the versality and quantity of the coated electrodes end high cost of inert gases eliminated the interest in gas shielding processes at that time. The electrode, bare solid wire that is comes the filler metal as it is consumed. The electrode, weld puddle, arc and adjasent areas of the base metal are protected from atmospheric contamination by a gaseous shield provided by a stream of gas, or mixture of gases, fed through the electrode holder. The gas shield must provide full protection, because even a small amount of entrained air can contaminate the weld deposit. The cost of arc welding consist of four major items which are the labor and overhead, electrodes, shielding gas and electric power. Arc Welding Systems was started at the beginning of 1930 years and it become best connecting way in 15 year and by the new development in time being it is still best connection way. Gas Tungsten - arc welding ( often called TIG welding ) is an arc welding process in which the heat is produced between a nonconsumable electrode and the work metal. The electrode, the weld puddle, the arc, and adjasend heated areas of the workpiece are protected from atmospheric contamination by a gaseous shield. This shield is provided by a stream of gas (usually inert gas), or a mixture of gases. The gas shield must provide full protection; even a small amount of entrained ait can contaminate the weld. The cost of welding for a specific applications is one of the most important factors for determining whether or not shielded metal arc welding should be used. The calculation method used in this processes can also be used to compare the consist this welding process with other welding process. Cost of electrodes and electrod performance must both be evaluated in calculating the effect of electrode selectionon welding cost. When more thanone welding process can produce acceptable results, the choice depends primarily on equipment available, skill of the welder.number of similar weldments to be produced, and cost. Xll Shilded metal-arc welding is the most versatile arc welding process, but is not always the lowest in cost or fastest. Although there are applications for which several welding processes may be suitable alternatives to shielded metal-arc welding, for most applications gas metal arc welding and flux cored arc welding are the closely competitive processes. Both arefaster than shielded metal arc welding in terms of rate of metal deposited. Because both are semiautomatic processes (that is, the filler metal is suppied at an established rate from coil.), arc time can be higherpercentage of total time than in shielded metal arc welding. In addition, both welding processes can e fully automated, Aside from these important advantages, however gas metal arc welding and flux cored arc welding generally are less versatile than shielded metal-arc welding. In the present time, majorities of the welding tasks are still done by manual means that require high level of welder skill and dexterity. However, harsh conditions evcountered during the application of welding process, like intense heat and fumes, the requirement for repeatable and consistent welding and the need for improved productivity, lover costs with high quality demanded for a better and more efficient way of welding. Automation of the gas metal arc welding process results in process and equipment requirements which were totally independent from manual welding. Because, in manual welding the control of the welding machine and welding technique may change from a welder to another. For this reason, automatic gas metal arc welding systems were developed for a specific type of welding tasks. At the begining inveatment of automatic systems seems expencive but in the long term it is more profitable. The cost of welding is an important factor to consider when determining whether to use this process. Gas tungsten arc welding is expensive and not wery economical, to use on thick metal, but on many other applications it will be best method. Because this process can be used to weld very thin metal, dissimilar metals, and wide variety of non ferrous metals, it is often chose for its capabilities with less considiration given to cost factor. In some cases, it is only welding proces that is practical to use. The initial investment cost for this process can vary widely depending on the complexity of the equipment required. This can range from a high frequency current and inert gas attachment added to a shielded metal arc welding machine up to a fully automatic welding head and a programmable power source. There are also many possibilities that exist between these extremes. The type of equipment used depend on the type of application. Xlll Cost of consumables can alsovary widely because of the price differences for the different shielding gases and filler metals. For some applications, no filler metal is used and for the welding of some of the more exotic metals, filler wire can be very expensive. The cost of many arc welding process consist o four major items. These are: 1- the labor and overhead cost 2- the filler metal cost 3- the shielding gas cost 4- the electric power cost