Spot welding-resistance welding processes, Mechanical Engineering

Assignment Help:

SPOT WELDING

In this type of welding, after proper cleaning of the surfaces, the metals to be welded are kept one above the other and two copper electrodes are kept on both sides of the plates. The weld cycle consists of four periods.

A) Squeeze Time: A pressure is applied to the electrodes and maintained for a particular interval before further operations start and this time is called squeeze time.

B) Weld Time: This is the period during which the weld current is applied. The duration of application of current is always measured in terms of the number of cycles; each cycle corresponds to 20 ms. (1 / line frequency). The pressure is also maintained during this time.

C) Hold Time: After the passage of current is cut off, the pressure has to be maintained for a brief interval of time so that the heated metal solidifies and forms a weld nugget. This period is called hold time.

 D) Off Time: This is the time for which we have to wait at the end of the spot welding before starting any other welding operation on the materials. Usually, resistance welding is carried out at line frequency (50 Hz) but for some applications high frequency (450 KHz) resistance welding is also employed.


Related Discussions:- Spot welding-resistance welding processes

Strengh of material, case study of thermal stresses and composite bar

case study of thermal stresses and composite bar

Find distance of which wagon will travel before coming rest, Find distance ...

Find distance of which wagon will travel before coming rest: A train of wagons is first pulled on level track from A to B and then up a 5 percent upgrade as shown in the figur

Cycle, defference between rankine and cornot cycle

defference between rankine and cornot cycle

A common cell control software, A Common Cell Control Software  In this...

A Common Cell Control Software  In this section, fine and common implemented cell control software are developed, that is based upon a transition table, to show the restriction

Thermodynamics, What are significnces of quasi static process

What are significnces of quasi static process

Thormodynamics, define thormodynamics and its laws

define thormodynamics and its laws

Design air coolers for plant layout, Q. Design Air Coolers for plant layout...

Q. Design Air Coolers for plant layout? As air coolers (sometimes called aerial coolers, or fin-fans) have extensive heat transfer surfaces, they are more vulnerable to failure

Dynamics, a motorcycle is used to stunt show to go over a valley . if the i...

a motorcycle is used to stunt show to go over a valley . if the initial speed at A is u m/s, determine a. the minimum U so that the motorcycle reaches the bank at B. b. the veloc

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