Advanced welding technology PPT All Information is here

1. ADVANCED WELDING
TECHNOLOGY
PRESENTED BY: MD SHOHRAB ALAM
ROLL NO: 26300719002
DEPARTMENT: MECHANICAL ENGINEERING
YEAR:2019-2023
SEMESTER: 7TH SEMESTER
TOPIC NAME: ADVANCED WELDING
TECHNOLOGY

2. Welding Definition & Classification
 Process of permanent joining two materials (usually metals) through
localised coalescence of heat or force.

3. Selection of the welding process
 Nature of joint
 Materials to be welded
 Geometry of component
 Quality
 Strength & mechanical properties
 Time factor
 Cost
 Welding Environment
 Source of energy

4. Gas Welding
 2C2H2 + 2O2 ----- 4CO + 2H2 + Heat
 4CO + 2H2 + 3O2 ---- 4CO2 + 2H2O + Heat

6. Types of Flames

7. Comparison b/w Flames
S. No. Neutral Flame Oxidizing flame Reducing Flame
Temperature
Materials
O2:C2H2
3200
CI, MS, SS Cu,
Al
1:1
3300
Cu or Zinc alloys
1.2:1
3100
Lead ,HSS
1:1.2

8. Oxy- Fuel Welding
 Oxygen is used with other fuel gas to
produce flame & coalescence of heat.
1. Hydrogen
2. Propane
3. Butane
4. Natural gas

9. Advantage
 Most versatile.
 Considerable control over temp. by varying supply of gases.
 Deposition rate is controlled
 Low cost & versatile equipment
 Portable & low maintenance

10. Disadvantage
 Not for heavy sections
 Lower temp of flame limits its use.
 Flux used causes irritating smoke.
 Refractory metals & reactive metals cannot be welded
 Long heat up time
 Larger HAZ
 More safety & handling problem with gases.

11. APPLICATION
 Joining up to thickness 8 mm.
 Materials having harmful effect of rapid heating &
cooling.
 Materials like- CI, SS, LCS, HCS, Cu, Zn, Ni, Mg etc.
 In automobile & aircraft industry for sheet-metal
applications.

12. Arc Welding

13. PRINCIPLE
 Heat is generated from arc struck between
an electrode & work piece.
 Temp.= 5500 Celsius
 Stand off dis.= 1 - 5 mm.
 Arc length = 0.6 - 0.8 of electrode dia.
 Current =150 – 1000 Amp.
 Voltage = 40 - 45 volts (DC)
50 -60 volts (AC)

14. ARC GENERATION
Supplyison, voltageisapplied,electrode& w/parestucktogether andhencecurrentflowstarts;
thenthe electrodeiskept2-5mmanddueto currentflowelectronjumpsgap& ionizationof gap
takesplaceandarcis initiated.
 Methodsto initiatearc:
1. TOUCHMETHOD
2. PASS-AWAYMETHOD

15. Varients
1. Carbon Arc Welding.
2. ShieldedMetal Arc Welding.
3. Submerged Arc Welding.
4. TIG(or GTAW) Welding.
5. MIG(or GMAW) Welding.
6. Electroslag Welding.
7. Electrogas Welding.
8. PlasmaArc Welding.
9. Arc Spot Welding.
10. Stud (Arc) Welding.

16. Tungsten Inert Gas ARC WELDING
(TIG/GTAW)
• Heat is generated by electric arc struck
between a tungsten electrode and the job.
• A shielding gas (argon helium, nitrogen, etc.)
is used to avoid atmospheric contamination of
the molten weld pool.
• A filler metal may be added, if required.

19. SPECIFICATION 0f TIG
• Temp. = 5500 Celsius
• Welding torch angle= 70- 80 degrees
• Filler rod angle= 10-20 degree
• Current= 100-500 Amp
• Electrode diameter = 2-5 mm
• Filler rod diameter = 2-6 mm
• Flow rate of gases = 7-11 lit/minutes
• Electrode material = W, W alloys, Thoriated W,
Zerconiated W.
• Shielding gases = Ar, Ne, He etc

20. ADVANTAGE
 Applicable to wide range of materials
(ferrous & non-ferrous).
 Good for welding thin sections (0.125mm)
and delicate work pieces
 high quality and appearance of weld.
 Clear visibility
 No flux entrapment risk

21. DISADVANTAGE
 Restricted to flat or horizontal welding.
 W in weld pool causes seviour problem
 Filler rod end causes contamination of
weldment
 Costly.

22. APPLICATION
 Al, Mg, Cu, Ni, and their alloys.
 Carbon alloys, SS, High temp & hardsurfacingalloys like Zr, Ti.
 Welding thinner sections.
 Welding of expansion bellows, transistor cases, instrument
diaphragm& sealingjoints
 Rocker motor chamber fabrication in launch vehicles.

23. METAL INHERT GAS ARC
WELDING
(MIG)
• Heat is generated by electric arc struck between a
consumable metal electrode and the job.
• A shielding gas (argon helium, nitrogen, etc.) is
used to avoid atmospheric contamination of the
molten weld pool.
• It needs Wire Electrode feed mechanism.

24. Process of MIG

25. ADVANTAGE
 Versatility - readily applied to a variety of applications and a
wide choice of electrodes
 Relative simplicity and portability of equipment
 Low cost
 Adaptable to confined spaces and remote locations
 Suitable for out-of-position welding

26. DISADVANTAGE
 Not as productive as continuous wire processes
 Likely to be more costly to deposit a given quantity of metal
 Frequent stop/starts to change electrode
 Relatively high metal wastage (electrode stubs)
 Current limits are lower than for continuous or automatic processes
(reduces deposition rate)

27. RESISTANCE WELDING
• Heat generated at interface due to resistance offered.
H= I*I*R*T
• Autogenous Weld (no filler needed)

28. Variants
 Spot welding
 Seam welding
 Projection welding
 Upset/Butt welding
 Flash Butt welding
 Percussion welding

29. Electrode Material
 0.99Cu 0.1Cd- LCS, Al & Mg alloy.
 0.992Cu 0.8Cr- SS, Ni alloy, Ni plated
steel
 0.05Be 0.1Ni 0.1Co 0.975Cu- Low
electrical & high thermal conducting
materials.

30. SPOT WELDING

31. Welding steps
 SQUEEZE TIME- Both workpices are squeezed together, by
app of pressure by electrodes.
 CURRENT SUPPPLY- Now welding current is applied for short
time.
 HOLD TIME- Current is off but the forces remains applied for
proper weld.
 OFF TIME- the forces on the work is removed.

32. PARAMETERS & USES
 Voltage= 5-25 volts
 Current= 100-5000 Amp
 Time= 0.06-3 sec
Materials welded
 Ferrous- Hardanable steel, HSS, SS, Coated Steels etc.
 Non-Ferrous- Al, Al-Mg alloys, Al-Mn alloys, Cu, Cu-Al alloys, Ni, Ni
alloy, Monal (Ni-Cu) alloys etc.

33. ADVANTAGE
 Low cost
 High welding speed
 Less skilled labor.
 Elimination of wrapping/distortion of parts
 High uniformity & quality of products
 Easy automation
 No need of edge preparation

34. APPLICATION
 Spot weld up to 12.5mm thickness
 Attachment of braces, brackets, pods, clips of box,
container & trays are welded
 Automobile & aircraft industry.
 Joining sheet metals

35. SEAM WELDING

36. ADVANTAGE
 Gas & liquid tight welds.
 Overlap may be less than spot
welding
 Single seam weld or parallel
welds can be produced
DISADVANTAGE
 ONLY STRAIGHT OR UNIFORM
CURVE CAN BE WELDED
 DIFFICULT TO WELD THICKNESS
MORE THAN 3MM
 SPECIAL DESIGNE OF WELD
ROLLS
APPLICATION
•ROUND, SQUARE, RECTANGULAR WELDS
•EXPECT Cu & HIGH Cu ALLOYS ALL OTHER MATERIALS ARE
WELDED
•CAN BE USED FOR LAP, BUTT JOINTS

37. PROJECTION WELDING

38. PRINCIPLE
 Current flow is concentrated at the contact surface by
an embossed projection.
 Projection effectively localizes the current

39. ADVANTAGE
 No of simultaneous weld
 Thick joints
 Less interference by rust, oil & work coating
 Long electrode life
 Can be used for complicated shapes
 Better heat balance
 Lower current & pressure

40. DISADVANTAGE
 Limited to metals which can be embossed
 For proper weld all projection must have equal height.

41. APPLICATON
 Various automobile parts
 Small fasteners & nuts can be welded
 Refrigerator condenser
 Cross wire welding
 Grating of boilers
 Household grills.

42. FRICTION WELDING
• solid-state welding
• Heat through mechanical friction b/w a moving work
piece & a stationary component .
• Technically, because no melt occurs, so its a forging
technique .

43. Friction Welding Process

44. Process Parameters

45. Process Specification
 Peripheral velocity= 50-200 m/min
 Axial pressure= 30-200 N/mm2
 Material Welded- Al, Ti, Ni, Cu and their alloys,
Brass, Bronze, Mg, Carbon steel, SS, Tantalum etc..
 Dissimilar material welds- Alloy steel to carbon
steel, super alloys to carbon steel, SS to carbon steel

46. ELECTROSLAG WELDING
• Highly productive, single pass process (thickness 25-300 mm)
in a vertical position
• Arc is initially struck by wire fed into the weld location & then
flux is added.
• Additional flux is added until the molten slag extinguishes
the arc.
• The wire is then continually fed and the filler metal are then
melted using the electrical resistance of the molten slag to
cause coalescence.

47. Processes

49. Points to Consider
ADVANTAGE
 Butt & T joint square face
 Large thickness upto 600mm
 Alloy steel are welded
 Extremely high deposition rates
 Residual stress & distortion is low
 Low flux consumption
 No spattering & flashing occurs.
DISADVANTAGE
 More costly for section below
60mm
 Hot cracking
 Tends to produce larger grain size
 Limited to vertical & uphill
position
 Tendency to notch sensitivity in
HAZ

50. APPLICATION
 Heavy casting, forging plates (butt weld)
 Welding of thick LCS & MCS.
 High strength structure steel
 Large cross-section of flyovers, structures, marine ships etc.

51. WELDING of CAST IRON
 Good fluidity & high solidification shrinkage.
 SMAW, GMAW, Oxy-fuel, flux coated arc, Termite welding processes are applicable
Grey CI:
 Certain precaution like preheating & low cooling rates.
White CI:
 Considered as un weldable.
Malleable CI:
 Post weld heat treatment
 Very low cooling rates to prevent it to change to White CI.
Nodular CI:
 Proper flux is needed to prevent losing of Mg which is responsible for ductility.

52. WELDING of ALUMINIUM
 Higher heat input needed (Reverse DC polarity)
 Thick sections needs preheating
 High reflective hence no red colour is appered during heating
 GMAW, GTAW, Resistance welding is common.
 PAW, EBM are specially used
 SMAW & oxy fuel welding are used when strength is not essential

53. WELDING of STEEL
LCS(0.13-0.3 %C):
 arcweldingispreferred
MCS(0.3-0.5 %C):
 Preweldheattreatmentiscommon
 Post weldheattreatmentissometimesnecessaryforthinsections
HCS(0.5-1.5%C):
 Pre& Postweldeattreatmentis essential
 LowH, S weldingprocess
 Shouldbe weldedinannealedcondition
HIGH STRENGTH LOW ALLOY STEELS:
 SMAW, TIG/MIG,Fluxcoated,Submergedarcweldingareapplicable.
 LowHydrogenwelding
 Resistanceweldingcanbe applied

54. SOLDERING
• Two or more metal items are joined together by melting and
flowing a filler metal into the joint
• The filler metal having a relatively low melting point
• Soldering is characterized by the melting point of the filler
metal, is below 400 °C
• The filler metal used in the process is called SOLDER
• It is distinguished from welding by the base metals not being
melted during the joining

55. Process- Soldering

56. Application
 Assembling electronic components to printed circuit
boards
 Permanent but reversible connections between copper
pipes in Plumbing systems
 Jewelry components are assembled and repaired by
soldering

57. Solders
 tin-lead(general purpose)
 tin-zincfor joining aluminum
 lead-silver for strengthat higher thanroomtemperature
 cadmium-silver for strengthat high temperatures
 zinc-aluminumfor aluminumand corrosionresistance
 tin-silver and tin-bismuthfor electronics

58. Typical Soldering Example