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

Access considerations for plant design, Q. Access Considerations for plant ...

Q. Access Considerations for plant design? Plant facilities shall be provided with acceptable access and egress for personnel, materials, and equipment by using access ways, ro

Reinforced earth walls, Reinforced Earth Walls: When constructing ROB...

Reinforced Earth Walls: When constructing ROBs, fly-overs and underpasses, it is often not possible to provide sloped earthen embankments for the approaches, which are as hig

Use of trusses, Use of trusses: Where do you find trusses in use? ...

Use of trusses: Where do you find trusses in use? The main uses of truss are as follows: 1. The trusses are used to support slopping roofs. 2. Brick trusses are

What is metal working processes, Q.What is Metal working processes? Met...

Q.What is Metal working processes? Metal working processes are processes used to produce wrought products. These product include angles, channels, I-beams, round, squar

Changes in mechanical properties along with tempering, Changes in Mechanica...

Changes in Mechanical Properties along with Tempering: Tempering enhances the toughness and ductility of quenched steel though decreases hardness. Following figure demonstrate

Reinforced concrete design, You are tasked with the analysis and design of ...

You are tasked with the analysis and design of the gravity and wind framing system for a 6-story office building. A part plan of the building is attached.  The plan dimensions o

Governor, Use of hartung governor

Use of hartung governor

Torsion, diameter = 100mm length = 470mm power = 4000 w radians = 78 shear ...

diameter = 100mm length = 470mm power = 4000 w radians = 78 shear modulus 60000 n/mm^2 determin the maximum shear stress and angle of twist

What are the points importants during forging design, What are the points t...

What are the points that should be kept in mind during forging design? Some of the points which must be followed while forging design are: > A radial flow of fibers or grain

Rankine Cycle, In a nuclear power plant saturated steam at 30 bar enters a ...

In a nuclear power plant saturated steam at 30 bar enters a h.p. turbine and expands isentrophically to a pressure at which its quality is 0.841. At this pressure the steam is pass

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