Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Flash Butt Welding-Flashing
The phenomenon of flashing is of extreme importance in achieving satisfactory welds. Flashing can begin only after a molten bridge has been formed somewhere along the interface. If the parts fit accurately, difficulty in initiating the process may be experienced and it may be necessary to level the butting surfaces to give local contact. This procedure is much different from that for resistance pressure welding where a good fit is desirable to exclude the atmosphere and prevent surface contamination. In the flash welding, surface contamination is removed in the spatter during flashing and molten metal is expelled in the final upset or forging operation.Once a molten bridge has been formed it is set in motion over the interface by the electrodynamic forces resulting from the distortion of the current path through the work pieces. While it traverses over interface at a speed of 10 cm / s, more heat is generated in the bridge by the joule effect and is lost to the colder metal at each end. Assuming the bridge does not freeze, it will be broken in one of two ways. It may either explode because of the combined influence of overheating and the pinch effect or it may race to the edge of the work piece where it becomes extended in the form of an arc between the work faces until it ruptures. In either event, much of the metal contained in the bridge is propelled out of the joint as spatter.Because, there is inevitably considerable inductance in the secondary circuit, collapsing of the electrical field at rupture results in a voltage surge which is capable to initiate an arc, although the open circuit voltage cannot sustain it and it is rapidly extinguished. The Considerable heat is generated in these brief arcing periods which accounts for the efficiency of the process compared with resistance butt welding.
Explain the Isolated System - Thermodynamic In an Isolated system, neither masses nor energy are permitted to cross the boundary. The system comprises certain mass and energy.
Track Renewal: Need for Track Renewal Normal maintenance is able to keep up the track standards only to a limited extent. The track gets overaged or the speeds and tr
Vented Causeway: Vented causeways are structures provided with vents (usually pipes) to take care of dry weather perennial flows and which allow water to overflow the paved b
Compute the angular velocity of bar: A bar AB as shown in slides so that its bottom point A has a velocity of 4 m/sec to the left along the horizontal plane. Compute the veloc
a) The voltage v across a capacitor at time t seconds is given by the following table t: 0 2 4 6 8 v: 150 63 28 12 5.6 Use the method of least square to fit a curve of
A 415 V, 5 kW, 50 Hz, 4-pole, 3-phase wound-rotor induction motor has the following characteristics: Stator winding resistance R 1 = 2.1 Ω, Referred rotor windi
Types of Brake The brakes used in motorcycles can be classified as follows: (a) Drum Brake (b) Disc Brake
define elastomer.explain in details?
Characteristics Of Computer Controlled Scheduling (Ccs) To control the manufacturing system in an effectual way, the system is normally composed in a task-based hierarchy. T
Atomic Hydrogen Welding In this process, an arc is struck between two tungsten electrodes using AC power supply.The Streams of hydrogen gas are passed from orifices around the
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd