Spray transfer, Mechanical Engineering

Spray Transfer

In a gas shield of argon or argon rich mixture [i.e., Ar+CO2 gas mixture containing more than 80 % argon] the metal transfer changes from globular to spray type as welding current is increased beyond the transition current. The current value at which the metal transfer mode changes from globular to spray is known as transition current.This type of transfer has a typical fine arc column and pointed wire tip associated with it. A very fine stream of droplets is projected axially through the arc. This mode of transfer is specifically called as streaming spray transfer. It occurs more readily with high resistivity, small diameter wires (eg. Austenitic stainless steel). The reduction in droplet size also accompanied by an increase in the frequency of droplet transfer. One important characteristic of spray mode of transfer is the "finger" penetration which it produces. The spray transfer mode can be used to weld any metal. However, applying the process to thin sheets may be difficult because of the high currents needed to produce the spray arc. Also the large weld pool produced due to the high deposition rate makes it difficult to use it vertical or overhead positions.

When CO2 is used for shielding, a globular to spray transition does not occur. Drops become smaller as the increases, but they are not at all axially directed. The spatter is more than that with argon or argon rich mixed gas shield.The spatter is minimised if "buried arc" technique is used. Buried arc technique involves using a low voltage for any given current, forcing the arc to locate within the cavity created by the arc force. Under this condition, most of the non axially directed droplets are trapped in the weld pool.

Posted Date: 9/17/2012 1:35:05 AM | Location : United States







Related Discussions:- Spray transfer, Assignment Help, Ask Question on Spray transfer, Get Answer, Expert's Help, Spray transfer Discussions

Write discussion on Spray transfer
Your posts are moderated
Related Questions
Q. Define the project scope? The Design Basis Memorandum defines the project scope. This includes basic design concepts and the basis and philosophies upon which the project s

Resultant of force system: Resultant is single force that produces the same effect as produced by the number of forces jointly in the system. In equilibrium magnitude of resul

Why dryness fraction are importance for steam power plant in terms of safety and economic ?

The Contractor is responsible for obtaining all drawings, standards and specifications referred to in the bid documents and to request as needed additional or missing reference dat

He a t: Sol: Heat can be energy transferred across the boundary of a system because of temperature difference between system and surrounding. The heat is transferred by th

Aluminium Cast Alloys: Aluminium alloys the cast through any one of the given processes. Sand Casting is the easiest and most versatile process minute castings, complex ca

Need of a spectrophotometer: The specific instructions will differ with other models, but the principles remain. 1. The instrument must have been warm for at least 15 min.

Battery: Battery is a device that produces direct current (DC). The chemical energy of battery ingredients converts into electrical energy in the form of direct current. This is a


Battery Inspection :  A fully charged and properly maintained battery is essential for proper lighting and starting of the motorcycle. STEPS Remove the right side cov