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
Explain the Intensive Properties of a System Intensive properties are those, which have similar value for any part of the system or the properties which are independent of the

APPLICATION OF GOVERNOR

HOW TO SIZE RECIRCULATION HOT WATER PUMP?

Discover the maximum safe air pressure: A cylindrical compressed air drum is equal to 2 m in diameter along plates 12.5 mm thick. The efficiencies of the longitudinal (η l ) a

A single jet pelton wheel runs at 300 rpm under a head of 510 m. the jet diameter is 200m, its deflection inside the bucket is 165 o and its relative velocity is reduced by 15% be

Determine the distance of application of the load: A rigid bar of negligible weight transmits a load W to a combination of 3 springs as illustrated in Figure. The three spring

A machine having a mass of 100 Kg and supported on springs of total stiffness 7.84 x 105 n/m has an unbalanced rotating element which results in a disturbing force of 400 N at a sp

ladder slip: A uniform ladder having length of 7m rests against vertical wall with which it makes an angle of 45º, coefficient of friction between ladder and wall is 0.4 and

VISUAL REALISM: Hidden line and surface removal eliminates the ambiguities of the displays of three-dimensional models and is considered the first step toward visual realism.

Q. What is the procedure of hot working? A process is defined as hot working if it takes place when the workpiece is above the recrystallization temperature. Hot Working Ad