“RESISTANCE WELDING”

PRESENTATION

Chandra Dini (02810)Ilham Romadhona (02858)Ferry Andriawan (03842)Veronika Nurdiana (05383)

GROUP 5

Welding is the process of joining two pieces of metals by heat the parts, with or without

pressure until melting, and then freeze and two metals joining. 

What is welding???

Resistance Welding is a welding process, in which work pieces are welded due to a combination of a pressure applied to them and a localized heat generated by a high electric current flowing through the contact area of the weld.

RESISTANCE WELDING

Low carbon steels - the widest application of Resistance Welding

Aluminum alloysMedium carbon steels, high carbon

steels and Alloy steels (may be welded, but the weld is brittle)

The following metals may be welded by Resistance Welding

High welding rates;Low fumes;Cost effectiveness;Easy automation;No filler materials are required;Low distortions.

Advantages of Resistance Welding:

High equipment cost;Low strength of discontinuous welds;Thickness of welded sheets is limited - up to

1/4” (6 mm);

Disadvantages of Resistance Welding:

The most popular methods of Resistance Welding are: 

Resistance

WeldingSpot

Welding (RSW)

Seam Welding (RSEW)

Resistance Butt

Welding (UW)

Flash Welding

(FW)Percussion

WeldingProjection Welding HFRW

Spot Welding is a Resistance Welding process, in which two or more

overlapped metal sheets are joined by spot welds.

The method uses pointed copper electrodes providing passage of electric current. The electrodes also transmitt

pressure required for formation of strong weld.

Diameter of the weld spot is in the range 1/8” - 1/2” (3 - 12 mm).

Spot Welding

Spot welding is widely used in automotive industry for joining vehicle body parts.

Single spot welding

Single and Multiple Spot Welding

Multiple Spot Welding

Seam Welding is a Resistance Welding process of continuous joining of overlapping sheets by passing them between two rotating electrode wheels. Heat generated by the electric current flowing through the contact area and pressure provided by the wheels are sufficient to produce a leak-tight weld.

Seam Welding

Seam Welding is high speed and clean process, which is used when continuous tight weld is required (fuel tanks, drums, domestic radiators).

Flash Welding is a Resistance Welding process, in which ends of rods (tubes, sheets) are heated and fused by an arc struck between them and then forged (brought into a contact under a pressure) producing a weld.

The welded parts are held in electrode clamps, one of which is stationary and the second is movable.

Flash Welding

Thick pipes, ends of band saws, frames, aircraft landing gears are produced by Flash Welding.

Resistance Butt Welding is a Resistance Welding process, in which ends of wires or rods are held under a pressure and heated by an electric current passing through the contact area and producing a weld.

Resistance Butt Welding

The process is similar to Flash Welding, however in Butt Welding pressure and electric current are applied

simultaneously in contrast to Flash Welding where electric current is followed by forging pressure application.

Butt welding is used for welding small parts. The process is highly productive and clean. In

contrast to Flash Welding, Butt Welding provides joining with no loss of the welded

materials.

Percussion or Percussive welding is similar to flash welding except that the arc is produced by the rapid discharge of stored electrical energy across an air gap between the ends of the work pieces to be welded.

Percussion Welding

Principle of Operation

Applications of Percussion Welding:1. Welding of satellite tips to tools2. Welding of Steel to Cast Iron3. Welding of Zinc to Steel4. Welding of Copper to Aluminium5. Welding of Studs6. Join a stranded wire directly to a component pin on axis

Projection Welding (RPW) is a resistance welding process which produces coalescence of metals with the heat obtained from resistance to electrical current through the work parts held together under pressure by electrodes.

Projection Welding

The resulting welds are localized at predetermined points by projections, embossments, or intersections. Localization of heating is obtained by a projection or embossment on one or both of the parts being welded.

The Advantage of projection welding is that electrode life is increased because larger contact surfaces are used. A very common use of projection welding is the use of special nuts that have projections on the portion of the part to be welded to the assembly.

The Advantage

High frequency resistance welding (HFRW) is a resistance welding process which produces coalescence of metals with the heat generated from the resistance of the work pieces to a high-frequency alternating current in the 10,000 to 500,000 hertz range and the rapid application of an upsetting force after heating is substantially completed

High Frequency Resistance Welding

This process is ideally suited for making pipe, tubing, and structural shapes. It is used for other manufactured items made from continuous strips of material.

Thank You