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 lower pair. and kinematics chair

what is cone friction?

What is Data Unification To optimize the UPR data structures, during design we study the semantics of each data type of the supported CAD systems and identify data types that a

Sweep Representations  The simplest form of sweep is that produced by sweeping a two-dimensional area along an axis perpendicular to its plane. This form of sweep is most usefu

SAFETY IN TIG WELDING-Radiation Energy Hazard Radiant energy may cause injury to the welder in two areas, eye and the skin. Any personnel, whether the welder, inspection person

Hazardous Waste and Material Standards Each hazardous site must be examined and evaluated for its characteristics before workers are allowed entry. This will pre decide an


i need the micro etrusion process,how it is done

Types of Bridges and their Suitability: Bridging is a specialized filed of engineering science. It has very high degree of sill and expertise in this field, gathered from brid

write notes on internal treatement of water