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

Equipment for resistance welding-stored energy equipments, EQUIPMENT FOR RE...

EQUIPMENT FOR RESISTANCE WELDING-Stored energy equipments   Energy can be stored and further utilised for welding. One method of storing energy is in capacitors electrostat

Kleins construction, Kleins construction fr 90 degree and 180 degree angle

Kleins construction fr 90 degree and 180 degree angle

Calculate the axial deflection and angle of rotation, Calculate the axial d...

Calculate the axial deflection and angle of rotation: Any open coiled helical spring along with 10 complete turns is built of 16 mm diameter steel rod, the mean radius of the

Why is stress relieving in post-weld treatment necesaary, In case of welded...

In case of welded vessels why is stress relieving in the form of post-weld treatment necessary? When a metal is welded together the point at which two surfaces are joined are s

Determine the flow rate - material balances, 1. A continuous steady-state p...

1. A continuous steady-state process involving components A, B, and C is shown below, along with the known process information a) On the flowchart, assign variables for the unkn

Need for electron beam welding(ebw) process, NEED FOR ELECTRON BEAM WELDING...

NEED FOR ELECTRON BEAM WELDING(EBW) PROCESS   The major advantage resulting from the use of a vacuum environment with a working pressure of from 10 -5 to 10 -3 mbar is esp

Head pump, the pump, shown in the figure, is used to deliver water to a dis...

the pump, shown in the figure, is used to deliver water to a distribution system. there is no flow to or from reservoir A, but it is used to damp pressure and protect the pump. th

Space for coil removal, Q. Space for coil removal? Locations, of all co...

Q. Space for coil removal? Locations, of all coils clearly indicated on the drawings. Provide adequate space for coil removal, and access doors on both sides. Flexible connecti

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