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RESISTANCE WELDING
KELAS CM5
Bambang Suryadi
Jalu Prasetyo Sugiantoro
Aditya Darma M
Trihardika Biantoro
Resistance Welding is a welding process, in which work pieces are welded due to
a combination of a pressure applied to the...
 Low carbon steels - the widest application of Resistance Welding
 Aluminum alloys
 Medium carbon steels, high carbon s...
 High welding rates;
 Low fumes;
 Cost effectiveness;
 Easy automation;
 No filler materials are required;
 Low dist...
 High equipment cost;
 Low strength of discontinuous welds;
 Thickness of welded sheets is limited - up to 1/4” (6 mm);...
RESISTANCE WELDING
SPOT WELDING SEAM WELDING
PROJECTION
WELDING
FLASH WELDING
UPSET WELDING
PERCUSSION
WELDING
HIGH
FREQUE...
Spot Welding
Single spot
Welding Machine
Multi-Spot
Welders
Spot weld is probably the most common type
of resistance welding. The material to be
joined between two electrode, pressur...
The rule of spot welding
 Spot welding may be done on material as low as 0,0001”
in thickness
 And in joint having membe...
Single spot welding
Single and Multiple Spot Welding
Multiple Spot Welding
Single Spot Welding
 Two type of single-spot welding machines :
Rocker arm
Press-type
spot welders
Rocker arm spot weld machine
 Simple Machine
 Most common
 Has a two long each
holding a single
electrode with the
uppe...
Press-type spot welders
Have movable electrode
Welding head which
operate in a straight line
Have greater application
i...
Heat application
 Welding period in spot welding controlled by electronic, mecanical,
or manually operated device.
 Weld...
Technique for
securing better
heat balance in
spot Welding
A Condition
Smaller
electrode
On High
conductivity
metals
Larger
electrode
On Low
conductivity
metals
B condition
Using a high
thermal
resistance
electrode
On High
conductivity
metals
Using a high
thermal
resistance
electrod...
C condition
Increase the
thickness of the
higher conductivity
metals
Better secure heat
balance
Heat Balance
 r2 and r4 = conductivity of metals
 r1 dan r5= conductivity between surface
metals and electrode
 r3 = co...
Electrode
Type of electrode face :
Primary functions of Electrode
 Conduct the required heat to the weld zone
 Transmit the necessary force to the weld are...
Multiple spot welders
 Have a series of hidraulically or air
operated welding guns mounted in a
framework or header but/u...
IN multiple spot welding
Spot welding is widely used in automotive industry
for joining vehicle body parts.
SEAM WELDING
Electrodes
Current
Welding speed and Forces
Types of weld seams
Seam welding is similar to spot welding. Equipment is very similar
both in terms of welding current production, control an...
Seam Welding is high speed and clean process, which is used when
continuous tight weld is required (fuel tanks, drums, dom...
Electrodes
 Electrodes for seam welders are disk shaped rollers with different face
contours. The face of the rollers may...
Current
 The current Value for seam welding is contingent on several variables
,
But, As a rule correct current getting i...
Welding speed and Forces
WELDING SPEED
CAPACITY OF
MACHINE
ELECTRODE FORCE
FOR SEAM WELDING
ELECTRODE FORCE
FOR SPOT WELDI...
Types of weld seams
Mashed Seam
Join light gage
sheet metal with
thickness less than
1/16 ’’
Flanged Seam
The Flange Joint...
Projection Welding
Electodes
Metals adaptable for Projection
Welding
Projection Welding (RPW)
is a resistance welding
process which produces
coalescence of metals with
the heat obtained from
...
The resulting welds are localized at predetermined points by projections,
embossments, or intersections. Localization of h...
Electrode
Flat Area
Electrode is flat and
large enough
Irregular Area
Electrode is
Shapped
Determine Correct
Current & req...
Metals adaptable for Projection Welding
 Not all metals can be projection welded. Brass and copper as a rule
do not lend ...
The Advantage of projection welding is that
electrode life is increased because larger contact
surfaces are used. A very c...
FLASH WELDING
Flash Welding
 In flash welding the two pieces of metal to be joined are clamped in dies
which conduct the electric curre...
The basic steps in a flash welding sequence
are as follows:
 (1) Position the parts in the machine.
 (2) Clamp the parts...
advantages
 Flexible cross sectioned shapes
 Flexible positioning for similar cross section parts
 Impurities can be re...
Limitations
 Produce unbalance on three-phase primary power lines
 The ejected molten metal particles present a fire haz...
Applications
 Wheel Truck Rims
 Ball Bearing Raceways
 Bar Welding
 Strip Welding During Continuous Processing
 Pipel...
UPSET WELDING
 Is refferd to as butt welding. In this
process the metals to be welded are
brought into contact under pres...
Upset Welding
 Upset welding (UW) is a resistance welding process that produces
coalescence over the entire area of fayin...
Two variations
 Upset welding has two variations:
 (1) Joining two sections of the same cross section end-to-end (butt j...
Method of achieving heat balance
Upset velocity
 Higher Velocity Helps extrude Centerline Oxides Out
 1. Oxides Are Present Because Melting Points are hi...
Advantages
• Keeps Heat at Center Line During Upset
• Keeps Oxides Fluid
• Aids In Forcing Oxides Out
Disadvantages
• Ex...
PERCUSSION WELDING (PEW)
DEFINITION
Percussion welding is a process in which
heat is produced from an arc that is
generated by the rapid discharge...
PRINCIPLE OF OPERATION
 The arc is started by bringing the workpieces into light contact with each
other. On some equipme...
ADVANTAGES
The percussion procces is that heat penetration
is shallow around 0.010 inch
The process possible to weld ste...
DISADVANTAGES
The process has somewhat restriced
applications
The process generally confined to butt
welded
If used on ...
HIGH FREQUENCY RESISTANCE
WELDING (HFRW)
DEFINITION
HFRW employs a high frequency current
to generate the required heat for bonding
edges of metal
PRINCIPLE OF OPERATION
 The process is based on the use of current that reverses at a high
rate- 450,000 Hertz (cycles) a...
APPLICATION
 The process has wide application in fabricating tubes, pipes, structural
shapes, heat exchanger, cable sheat...
Resistance welding
Resistance welding
Resistance welding
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Resistance welding

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Resistance welding

  1. 1. RESISTANCE WELDING KELAS CM5 Bambang Suryadi Jalu Prasetyo Sugiantoro Aditya Darma M Trihardika Biantoro
  2. 2. 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
  3. 3.  Low carbon steels - the widest application of Resistance Welding  Aluminum alloys  Medium 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
  4. 4.  High welding rates;  Low fumes;  Cost effectiveness;  Easy automation;  No filler materials are required;  Low distortions. Advantages of Resistance Welding:
  5. 5.  High equipment cost;  Low strength of discontinuous welds;  Thickness of welded sheets is limited - up to 1/4” (6 mm); Disadvantages of Resistance Welding:
  6. 6. RESISTANCE WELDING SPOT WELDING SEAM WELDING PROJECTION WELDING FLASH WELDING UPSET WELDING PERCUSSION WELDING HIGH FREQUENCY RESISTANCE WELDING
  7. 7. Spot Welding Single spot Welding Machine Multi-Spot Welders
  8. 8. Spot weld is probably the most common type of resistance welding. The material to be joined between two electrode, pressure is applied, and the current is on. any 3 stage are involved in welding cycle : 1. Squeeze time 2. Weld time 3. Hold time Spot Welding
  9. 9. The rule of spot welding  Spot welding may be done on material as low as 0,0001” in thickness  And in joint having member as heavy as one inch.  The bulk of resistance welding is confined to metals that are lesss than ¼ “ in thickness.
  10. 10. Single spot welding Single and Multiple Spot Welding Multiple Spot Welding
  11. 11. Single Spot Welding  Two type of single-spot welding machines : Rocker arm Press-type spot welders
  12. 12. Rocker arm spot weld machine  Simple Machine  Most common  Has a two long each holding a single electrode with the upper arm providing the moving action
  13. 13. Press-type spot welders Have movable electrode Welding head which operate in a straight line Have greater application in welding heavier section.
  14. 14. Heat application  Welding period in spot welding controlled by electronic, mecanical, or manually operated device.  Weld time may range from one-half hertz (cycle) of a 60-hertz (cycle) frequency for light material to several seconds for thicker plate.  Weld time is important  The temperature must be high enough but not so great
  15. 15. Technique for securing better heat balance in spot Welding
  16. 16. A Condition Smaller electrode On High conductivity metals Larger electrode On Low conductivity metals
  17. 17. B condition Using a high thermal resistance electrode On High conductivity metals Using a high thermal resistance electrode Tungsten and molybdenum
  18. 18. C condition Increase the thickness of the higher conductivity metals Better secure heat balance
  19. 19. Heat Balance  r2 and r4 = conductivity of metals  r1 dan r5= conductivity between surface metals and electrode  r3 = conductivity between joined metals
  20. 20. Electrode Type of electrode face :
  21. 21. Primary functions of Electrode  Conduct the required heat to the weld zone  Transmit the necessary force to the weld area  Help the dissipate the heat from the weld zone Most electrodes for spot welding are made of low resistance copper alloy
  22. 22. Multiple spot welders  Have a series of hidraulically or air operated welding guns mounted in a framework or header but/using a common mandrel or bar for the lower electrode.
  23. 23. IN multiple spot welding
  24. 24. Spot welding is widely used in automotive industry for joining vehicle body parts.
  25. 25. SEAM WELDING Electrodes Current Welding speed and Forces Types of weld seams
  26. 26. Seam welding is similar to spot welding. Equipment is very similar both in terms of welding current production, control and pressing force. however, differs from spot welding mainly because of the rolling welding wheel. In most applications, wheels on both sides of the workpiece produce the weld. Seam Welding
  27. 27. Seam Welding is high speed and clean process, which is used when continuous tight weld is required (fuel tanks, drums, domestic radiators).
  28. 28. Electrodes  Electrodes for seam welders are disk shaped rollers with different face contours. The face of the rollers may be straight, beveled, or concave.  The straight and double beveled edge is used where there sufficient clearence on both side of the work.
  29. 29. Current  The current Value for seam welding is contingent on several variables , But, As a rule correct current getting is determined by Type of materials welding speed Thickness of the joint Used of water colling TRIAL AND ERROR BEST CURRENT
  30. 30. Welding speed and Forces WELDING SPEED CAPACITY OF MACHINE ELECTRODE FORCE FOR SEAM WELDING ELECTRODE FORCE FOR SPOT WELDING IS BIGGER THAN
  31. 31. Types of weld seams Mashed Seam Join light gage sheet metal with thickness less than 1/16 ’’ Flanged Seam The Flange Joint Is Frequently Employed In Fastening Tops And Bottoms To containers. Lap Seam THE WIDTH OF THE LAP FOR A STRONG QUALITY WELD IS USUALLY HELD AT ABOUT 1 ½ TIMES THE THICKNESS OF THE SHEETS.
  32. 32. Projection Welding Electodes Metals adaptable for Projection Welding
  33. 33. 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
  34. 34. 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.
  35. 35. Electrode Flat Area Electrode is flat and large enough Irregular Area Electrode is Shapped Determine Correct Current & require Pressure Trial Run Careful Inspection Estabilshed Current and Pressure
  36. 36. Metals adaptable for Projection Welding  Not all metals can be projection welded. Brass and copper as a rule do not lend themselves to projection welding because the projections collapse too easily under pressure. Aluminium projection welding is generally limited to extruded parts. Galvanized sheet- steel, tin plate, and stainless steel as well as most other thin gage steel can be successfully projection welded.
  37. 37. 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
  38. 38. FLASH WELDING
  39. 39. Flash Welding  In flash welding the two pieces of metal to be joined are clamped in dies which conduct the electric current to the work the ends of the two metal pieces moved together until an arc established
  40. 40. The basic steps in a flash welding sequence are as follows:  (1) Position the parts in the machine.  (2) Clamp the parts in the dies (electrodes).  (3) Apply the flashing voltage.  (4) Start platen motion to cause flashing.  (5) Flash the normal voltage.  (6) Terminate flashing.  (7) Upset the weld zone.  (8) Unclamp the weldment.  (9) Return the platen and unload.  The above slide illustrates these basic steps. Additional steps such as preheat, dual voltage flashing, postheat, and trimming of the flash may be added as the application dictates.
  41. 41. advantages  Flexible cross sectioned shapes  Flexible positioning for similar cross section parts  Impurities can be removed during upset acts  Faying surface preparation is not critical except for large parts  Can weld rings of various cross sections  Narrower heat-affected zones than those of upset welds
  42. 42. Limitations  Produce unbalance on three-phase primary power lines  The ejected molten metal particles present a fire hazard  Require special equipment for removal of flash metal  Difficult alignment for workpieces with small cross sections  Require almost identical cross section parts
  43. 43. Applications  Wheel Truck Rims  Ball Bearing Raceways  Bar Welding  Strip Welding During Continuous Processing  Pipelines
  44. 44. UPSET WELDING  Is refferd to as butt welding. In this process the metals to be welded are brought into contact under pressure an electric current is passed through them, and the edges are softened and fused together
  45. 45. Upset Welding  Upset welding (UW) is a resistance welding process that produces coalescence over the entire area of faying surfaces, or progressively along a butt joint, by the heat obtained from the resistance to the flow of welding current through the area where those surfaces are in contact. Pressure is used to complete the weld.  With this process, welding is essentially done in the solid state. The metal at the joint is resistance heated to a temperature where recrystallization can rapidly take place across the faying surfaces. A force is applied to the joint to being the faying surfaces into intimate contact and then upset the metal. Upset hastens recrystallization at the interface and, at the same time, some metal is forced outward from this location. This tends to purge the joint of oxidized metal.
  46. 46. Two variations  Upset welding has two variations:  (1) Joining two sections of the same cross section end-to-end (butt joint).  (2) Continuous welding of butt joint seams in roll-formed products such as pipe and tubing.  The first variation can also be accomplished by flash welding and friction welding. The second variation is also done with high frequency welding.  The general arrangement for upset welding is shown in the above slide. One clamping die is stationary and the other is movable to accomplish upset. Upset force is applied through the movable clamping die or a mechanical backup, or both.
  47. 47. Method of achieving heat balance
  48. 48. Upset velocity  Higher Velocity Helps extrude Centerline Oxides Out  1. Oxides Are Present Because Melting Points are high  2. Oxides Tend to Solidify or Harden and Get entrapped at the Interface  3. Rapid Velocity Helps Get Them Moving
  49. 49. Advantages • Keeps Heat at Center Line During Upset • Keeps Oxides Fluid • Aids In Forcing Oxides Out Disadvantages • Excess Heating Can Produce Excess Upset • More HAZ Fiber Turn Up
  50. 50. PERCUSSION WELDING (PEW)
  51. 51. DEFINITION Percussion welding is a process in which heat is produced from an arc that is generated by the rapid discharge of electrical energi between the workpieces and followed immediately by an impacting force which weld the pieces together.
  52. 52. PRINCIPLE OF OPERATION  The arc is started by bringing the workpieces into light contact with each other. On some equipment the arc started by superimposing an auxiliary high frequency AC voltage on a low-voltage direct current.
  53. 53. ADVANTAGES The percussion procces is that heat penetration is shallow around 0.010 inch The process possible to weld stellite tips to bronze or stainless steel valve stems or an aluminum fixture to stainless steel or cooper without affecting their metallurgical properties. The process is often used in welding wire, bar, and tubing
  54. 54. DISADVANTAGES The process has somewhat restriced applications The process generally confined to butt welded If used on larger section the arc fails to distribute itself evenly over the entire surface and unwelded spots result in the joint
  55. 55. HIGH FREQUENCY RESISTANCE WELDING (HFRW)
  56. 56. DEFINITION HFRW employs a high frequency current to generate the required heat for bonding edges of metal
  57. 57. PRINCIPLE OF OPERATION  The process is based on the use of current that reverses at a high rate- 450,000 Hertz (cycles) as compared with the line frequency of 60 Hertz (cycles).  Power supply for HFRW consist of a 60 to 560 kw radio frequency transmitter. The transmitter equipped with a rectifier.
  58. 58. APPLICATION  The process has wide application in fabricating tubes, pipes, structural shapes, heat exchanger, cable sheathing, and other parts where high speed is required  The procees can welded ferrous and nonferrous materials in thicknesses ranging from 0.004 inch to ½ inch in thickness.

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