Flash butt welding in railway is a process of welding in which there is a principle of electric short circuit involved which is connected with rail ends that act as DC poles. There is a high current that produces arcs between these ends. The two cross rail compartments are subject to heat such that the melting temperatures using this high voltage current. The coaches are subject to high pressures during the upset strokes which cause ends to finish. Then the remaining upset material is not of use after this stage. After all this process the result comes out to be an accurate welding, which is without the filler metal and with a very small zone that is heat affected. This is the consistent progression of hardening process that also involves crystal line structures.
Because of the shape of the rails there is irregular and distribution is not equal among them. This is because of the effect of the high temperatures that the flash butt weld is heated up to the melting temperatures. Further the rail does not cool equally over the whole section. The base and the foot cool at early stages and rest things after wards. When the high spots touch the points they automatically start melting. Just because there is largest proportion of the metal in the head so it takes the maximum time to get cool down. The natural faults occur in the areas where there are joints. There are many negative effects of this thing on track measurements and geometry related operation related concepts. There is a slight difference in two rails that can be adapted to the specific rail profiles so that the ideal positions of the rails can be achieved when the whole weld has cool down.
In alumino thermic welding there is only 56% of the parent rail and strength of the joints is the app. These have more rates of failure and are even more prone to the corrosion. These involve the poor quality of the weld. In case of flash butt the qualities are too good and even this is less prone to corrosion. The strength is almost equal to the parent rails. The failure rate is even less than 10%. The quality of the weld is excellent and various defects are eliminated from this concept. In case of mobile flash butt welding the machines are carried to the site so that the tasks can be performed. These are the standardized manners of performance. The railway weld is held in the positions in between coaches which should be reduced in the running tracks. No machine is completely computerized and some of the manual operations are involved in the whole concept. In case the position is set the process can be carried out automatically by just pressing a button. Various procedure approval tests have to be performed in flash butt welding in railway order to ensure the quality of the work they are going to do. Some of them are like bend and fatigue testing and macro examinations.