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
Is it possible for the steady state temperature profile in a plane wall to be nonlinear at steady state? If yes, provide one example. Solution: Steady state temperature profile

Nozzle: The pressure energy gets converted in to kinetic energy Mass flow rate  Turbine: It is used to generate work.  The work is done by system becaus

Differentiate Reaction turbine and Impulse turbine (steam turbines) (b) In a De Laval turbine, steam issue from the nozzle with a velocity of 850 m/s. The nozzle angle is 20 o C

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

a concrete column of 350mm diameter is reinforced with 4 bars of 25mm diameter . find the stress when the concrete is subjected to a stress of 4.5 MPa . also find the safe load in

Q. What do you mean by turret Nozzle? Turret Nozzle - Turret nozzles are large nozzles that can deliver large quantities of water quickly. They are used on very large fires whe

Q. Explain Rate Pressure Product? The systolic blood pressure is multiplied by the heart rate to provide the double product or modified fusion time index. On presence of an obs

Specific Properties of a System The extensive properties while estimated on the unit mass basis result in intensive property that is as well known as specific property. For exa

Phase 1 Initially ALL Valves A, B, C, D, E and F are closed.  ALL Tanks A, B, C, D, E are separated and each sealed from the atmosphere. Tank E initially has 2' of air @

WHAT IS DIFFERENCE BETWEEN POROSITY AND BLOW HOLE