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
Connecte d Rod: It is attached to piston at its small end by means of gudgeon pin. The big end bearing is connected to crank pin. It is made up of forged steel.

Q. Setting and installations of insulation? The setting and installations of insulation shall be to Specification No. later. The steam drum surfaces shall be insulated with

Compute minimum value of the horizontal force: Block A of weight 520N rest on horizontal top of block B having weight of 700N as shown in the figure given below. Block A

Q. Corrosion in Boiler? With proper BFW treatment, and maintaining pH within a certain range (9.2 to 9.4) and removing oxygen from the system, a stable passive film will be for

Getting Familiar: An entrepreneur wishing to set up an industry must first formulate a comprehensive plan for setting the industry for its success. For this, he/she should have co

Vitrification This is liquid phase sintering. It is achieved via incorporating a component that melts to viscous liquid during sintering. Such viscous liquid solidifies in gla

Q. Why we use Nickel Alloys in welding? Nickel weld metals have high creep-rupture strength but often have lower stress-rupture ductility and lower mechanical and thermal fatig

Specific volume of the superheated steam: It is volume occupied by unit mass of superheated steam corresponding to given pressure of superheated steam generation. Superheated

Q. Materials used in insulation? All materials must be non-corrosive, compatible with other materials and used in accordance with the Manufacturer's recommendations. All mat