Welding 101 Presentation

8/12/2019 Welding 101 Presentation

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Jason King, Paula Lobaccaro,

Meghan Olson & Lindsey Rappleyea


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Introduction Welding Joints

Welding Processes

Equipment and Technology Advantages and Disadvantages

Welding in Present Day Manufacturing

Safety

Economics Case Study


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Welding is a fabrication or sculptural processthat joins materials, such as metals orthermoplastics, by melting the parts and thenusing a filler to form a joint

Estimated: 50% of the gross national productof the U.S.A. is related to welding in one wayor another

Welding has done in unusual conditions,including underwater and in outer space


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Welding Processes

A materials joining process whichproduces coalescence of materials by

heating them to suitable temperatures

with or without the application of

pressure or by the application of

pressure alone and with or without

the use of filler material. - AWS


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Bronze Age: Welded Gold Boxes & EgyptianTools

Middle Ages: Blacksmiths 1800s: Use of open flames for welding 1880-1900: Development of arc welding 1920s: Automatic Welding 1940s: Development of Heliarc welding and

Gas Shielded Metal Arc Welding 1960s: Plasma Arc Welding Modern: Friction Welding, Laser Welding


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Advantages Simpler, faster and more cost effective than otherjoining methods

Parts do not need to fit together perfectly

Joint can potentially be stronger than the individualparts that are going to be joined

Can weld a wide range of metals and plastics

Can be used in unique environments

Can be an automatized process Equipment can be less expensive than other

manufacturing equipment


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Disadvantages Welds can contain defects; less reliable and

predictable

Joint is permanent, preventing future alterations

Not applicable to all materials Can be a liability due to training, expertise, and

safety required


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Pieces to be welded are laid side by side


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One piece to be welded in laid down andanother pieces is overlapped

Fillet, plug, and slot welds can be applied to

Lap Joints


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One piece to be welded in placed on anotherso that a corner is formed


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Two pieced to be welded come together andthe two edges are welded


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One piece of metal to be welded is placedvertically on top of another piece that ishorizontal, forming a T

Fillet welds are applied to T Joints


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Created in 1890 Commonly known as stick welding

Works with: carbon steel

high alloy steel

stainless steel

cast iron

ductile iron

copper

nickel


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Advantages Versatility - readily

applied to a variety ofapplications and a widechoice of electrodes

Relative simplicity and

portability of equipment Low Cost Adaptable to confined

spaces and remotelocations

Suitable for out-of-position welding

Disadvantages Not as productive as

continuous wireprocesses

Frequent stop/starts to

change electrodes Relatively high metal

wastage (electrodestubs)

Current limits are lowerthan for continuous orautomatic processes(reduces deposition rate)

Advantages vs Disadvantages


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Advantages Higher Productivity

Simple to Learn

Clean and Efficient

Versatile High Welding Speed

Simple and greatwelds

Disadvantages High start up cost

Limited Positions

Not Suitable for

Outdoor Welding Fast Cooling Rates

Unsuitable for ThickMetals

Shielding Gas Metal Preparation

Time



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Created in 1941 Commonly Known as TIG Welding Works with:

Mild Steel

Stainless Steel Aluminum Copper Nickel Copper Nickel Inconel Magnesium Titanium


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Advantages Applicable to a very

wide range ofmaterials

Especially good for

welding thin sectionsand delicate workpieces

Capable of producingwelds of high quality

and appearance

Disadvantages Generally restricted to

flat or horizontalwelding

Requires a higher levelof skill

Slower welds



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Electrical resistance across the two joiningcomponents produces the heat required forwelding

Typically used when welding particular types ofsheet metal

Disadvantages Bond strength depends on surface roughness & cleanliness Requires specialized machinery (generally non-portable)

Advantages: Many facilities now automated Commonly selected for use with robotics in automotive

manufacturing


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Resistance spot welding

Electrical energy is

the heat sourcenecessary for thecoalescence of twoor more metals


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joins metals without base metalmelting

produces coalescence attemperatures essentially belowthe melting point of the basematerials being joined

brazing filler material is notrequired


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Two processes: Electron beam

Laser

Beam can be used tomelt and vaporizemetals because suchhigh energy intensity

Energy transfer - notthermal transfer processes


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An electron beam (of high velocity electrons)generated in a vacuum creates a fusing heatsource

Advantages:

Can unite almost any metals Deep weld without adding excessive heat that can

adversely affect the properties of the surroundingmaterial

High Tolerances

Problems/Disadvantages Undercutting, cracking, lack of fusion, missedjoints, porosity, under fill, and shrinkage voids


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Joining takes place without fusion at theinterface Two surfaces brought together under pressure

No liquid or molten phase is present at thejoint

For strong bond, both surfaces must beclean:

No oxide films, residues, metalworking fluids,contaminants


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A group of 8 welding processes cold welding

diffusion welding

explosion welding forge welding

friction welding

hot pressure welding

roll welding ultrasonic welding


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Ventilation

Grounded

Protect neighboringworkers from

exposure to arc

radiation by shielding

your station.


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11. Time for changing electrodes.

12. Time to move the welder fromone location to another.

13. Time to change welding machine

settings.14. Time spent by personnel for

personal purposes.

15. Time to repair or re-workdefective welds.

16. Costs associated with any

required stress relief.17. Cost of electrodes.

18. Cost of shielding materials.

19. Cost of electric power.

20. Cost of fuel gas for pre-heat(when required).

1. Time for joint preparation.

2. Time to prepare the material forwelding (blasting, removal of oils,etc.).

3. Time for assembly.4. Time to preheat the joint (when

required).

5. Time for tack-up.

6. Time for positioning.

7. Time for welding.

8. Time to remove slag (whenapplicable).

9. Time to remove spatter.

10. Time for inspection.

Machines: $400-$7000+, Helmets: $20 - $500+,

Guns: $200-$3000+


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Most accurate method

Useful for welded parts that will move throughout a workspace

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Best when applied to single pass welds

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Easiest and most used (and misused) Best applied to large, multipass welds

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Robotic vs. Fixed Robotic arm moves on multiple axis

Increased productivity

Improved weld quality

Increased profitability Reduced labor costs 70% of welding costs

Single machine can replace3 workers

Reduced material waste

Used increasingly more often The car industry is a huge user of automated

welding


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Case study, looking at real time welding in theautomotive world

http://www.youtube.com/watch?v=spRyegwBhKg

Documents

Welding 101 Presentation