Arc initiation-touch start-high frequency start, Mechanical Engineering

Assignment Help:

ARC INITIATION


Touch Start
With the power supply energised and the shielding gas flowing through the cup, the torch is lowered toward the workpiece until the tungsten electrode makes contact with workpiece. Then torch is suddenly withdrawn a short distance to establish the arc. The benefits of this method of arc initiation is its simplicity of operation. The demerits of touch starting isthe tendency for the electrode to stick to the workpiece, causing electrode contamination and transfer of tungsten to the workpiece.


High Frequency Start
High frequency starting can be used with DC or AC power sources for both manual and automatic applications.Very High frequency generators usually have a spark gap oscillator that superimposes a high voltage AC output at radio frequencies in series with the welding circuit. The high voltage ionises the gas between the electrode and the work and the ionised gas will then conduct welding current that initiates the welding arc.


Related Discussions:- Arc initiation-touch start-high frequency start

Screw conveyors, Screw Conveyors: Screw conveyors are used principally f...

Screw Conveyors: Screw conveyors are used principally for transmitting materials in the form of powder or paste with the application of rotating screw. For example feedin

What is extrusion defects, Q. What is Extrusion defects? • Surface crac...

Q. What is Extrusion defects? • Surface cracking - When the surface of an extrusion splits. This is often caused by the extrusion temperature, friction, or speed being too high

Belt friction, Ask question # how to derive a expression for the centifugal...

Ask question # how to derive a expression for the centifugal tension in belt driver

What are the different theories of failure under static load, What are the ...

What are the different theories of failure under static load, explain briefly? The major theories of failure of a member subjected to bi-axial stress are as below: > Maximu

Capacitor discharge welding, Capacitor Discharge Welding This is used ...

Capacitor Discharge Welding This is used for welding of studs, welding of thermocouples, etc. on the base metal. A low voltage, high amperage electrical discharge from a capac

Analog control system for steam generator, Q. Analog Control System for ste...

Q. Analog Control System for steam generator ? The analog (modulating) control of the Steam Generators will be performed using a Process Control System (by Buyer). Detailed fun

Compute the force exerted by the tires on the road, Compute the force exert...

Compute the force exerted by the tires on the road: An automobile of mass 1500 kg traverses a 500 m curve at a constant speed of 50 kmph. Supposing no banking of the curve,

About Transfer Function block, How can i change the normal function block p...

How can i change the normal function block parameter[1 1]=>(s+1) to (s-1)?

Combined gas turbine/Rankine cycle, b. Assuming a 20 MW simple cycle gas tu...

b. Assuming a 20 MW simple cycle gas turbine with a firing temperature of 1600K develop an analysis of a combined cycle. Assume that Tmax in the Rankine cycle is 560 C, Pmax = 60

What will happen if air filter is not used?, (a) What will happen if air fi...

(a) What will happen if air filter is not used? (b) What are the components of an air filter? (c) What precautions should be followed while cleaning the air filter? (d) What grade

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd