Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Manufacturing Processes > Chapter 7: Welding > Flashcards

Chapter 7: Welding Flashcards

1
Q

Why is joining/assembling (welding) necessary

A
  1. Impossible or uneconomical to manufacture a product as a single piece
  2. Easier to manufacture as components, then assemble
  3. Product may have to be taken apart for maintenance
  4. Transportation of part as individual components may be easier/economical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Joining vs What is Assembling

A

Joining includes processes that form a permanent joint between parts (welding, brazing, soldering, and adhesive bonding)

Assembly involves mechanical methods of fastening parts together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is welding

A

A joining process in which two or more parts are coalesced at their contacting surfaces by application of heat and/or pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is welding important

A
  • Provides a permanent joint
  • Usually the most economic way to join parts
  • not restricted to a factory environment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Limitations and drawbacks of welding

A
  1. most performed manually resulting in being expensive in terms of labor cost
  2. most welding utilizes high energy which is dangerous
  3. Welded joints do not allow for convenient disassembly
  4. Welded joints can have quality defects that are difficult to detect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the safety issues associated with welding

A
  • high temperatures of molten metals
  • in gas welding, fuels are a fire hazard
  • Many welding processes use electrical power, so electrical shock hazard
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 5 types of weld joints and describe them

A
  1. Butt Joint - two parts joined parallel creating a groove between the two parts
  2. Corner joint - two parts are joined perpendicular at their edges to create a corner
  3. Lap joint - two parts are parallel with on top of the other creating a stair effect
  4. Tee joint - two parts are joined perpendicular with one part in the center of the other creating a T shaped part
  5. Edge joint - two parts (usually curved) are joined parallel with a lot of overlap
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the types of welds

A
  1. Fillet Weld
  2. Groove Weld
  3. Plug and Slot Welds
  4. Spot and Seam Welds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are fillet welds used for

A

Used to fill in the edges of plates by creating corner, lap, and tee joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Filler metal in fillet welds takes what shape

A

right triangle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Most common weld type in arc and oxyfuel welding

A

Fillet Welds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Type of weld that requires minimum edge preperation

A

Fillet Weld

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Type of weld that requires part edges to be shaped into a groove

A

Groove welds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the shapes grooves can take

A

Square, bevel, V, U, and J, in single or double sides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What type of joints are groove welds most associated with

A

Butt joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does spot welding and seam welding accomplish

A

A fused section between surfaces of two sheets or plates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is spot and seam welds used for

A

Lap joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are spot and seam welds most associated

A

resistance welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

This type of welding melts the base metal

A

Fusion Welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

This type of welding does not melt the base metal

A

Solid State Welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the three types of solid state welding

A

Diffusion welding
Friction Welding
Ultrasonic Welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the 3 types of fusion welding

A

Arc Welding
Resistance Welding
Oxyfuel Welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the two classifications of arc welding

A

consumable electrode welding
non-consumable electrode welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the two types of consumable electrode arc welding

A

SMAW - Shielded Metal Arc Welding
GMAW - Gas Metal Arc Welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the two types of nonconsumable electrode arc welding

A

GTAW - Gas Tungsten Arc Welding
PAW - Plasma Arc Welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the types of Resistance Welding

A

RSW - Resistance Spot Welding
RSEW - Resistance Seam Welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the type of oxyfuel welding

A

Oxyacetylene welding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Benefits of a filler metal

A

added strength and bulk

30
Q

What is a fusion weld with no filler metal called

A

Autogenous weld

31
Q

What is arc welding (AW)

A

melting of metals is accomplished by an electric arc

32
Q

What is resistance welding (RW)

A

Melting is accomplished by heat from resistance to an electrical current between fraying surfaces held together under pressure

33
Q

What is oxyfuel gas welding (OFW)

A

Melting is accomplished by an oxyfuel gas such as acetylene

34
Q

Problems with manual welding

A

Weld joint quality
Productivity or arc time

35
Q

Non-consumable electrodes are made of what

A

Tungsten

36
Q

What is arc shielding and why is it needed

A

In AW processes, the mechanical properties of the joint can be degraded by chemical reactions with the air due to high temperatures. So, arc shielding is using shielding gases or flux to protect the operation

37
Q

What is flux

A

A substance that prevents the formation of oxides and other contaminants in welding or dissolves them and facilitates removal

38
Q

What are the power sources available in Arc welding

A

Alternating Current (AC) or Direct Current (DC)

39
Q

Benefits and limitations of AC in arc welding

A

less expensive but restricted to ferrous metals

40
Q

Benefits and disadvantages of DC in AW

A

can be used on all metals and better arc control but more expensive

41
Q

What is Shielded Metal Arc Welding SMAW

A
  • Called stick welding
  • uses a consumable electrode consisting of a filler metal rod coated with flux for shielding
42
Q

What is Gas Metal Arc Welding GMAW

A

Uses a consumable bare metal wire as an electrode with shielding by flooding the arc with gas

43
Q

GMAW advantages over SMAW

A
  1. Better arc time - no sticks
  2. Better use of elctrode filler metal
  3. Eliminates slag removal
  4. Can be automated
44
Q

What is Gas Tungsten Arc Welding GTAW

A

Uses a non-consumable tungsten electrode and an inert gas for shielding
- filler metal is added seperately

45
Q

Advantages and Disadvantages

A

Advantages:
- High-quality welds
- No spatter because no filler metal through the arc
- little to no post-weld cleaning because no flux

disadvantages:
- generally slower and more constly

46
Q

What is Plasma Arc Welding PAW

A

A special form of GTAW in which a constricted plasma arc is directed at weld area

47
Q

Adv and diadv of PAW

A

Adv: good arc stability and weld quality and almost any metal

disadv: high cost and large torch size

48
Q

What is the principle RW process

A

RSW - Resistance spot welding

49
Q

Components in RSW

A
  • Parts (usually sheet metal)
  • two opposing electrodes
  • means of applying pressure
  • power supply
50
Q

pros and cons of RW

A

Pros:
- no filler metal
- high production rates
- low operator skill
- good reliability

Cons:
- high equipment cost
- limited to lap joints

51
Q

Primary Characteristic of RSEW

A

Uses wheel electrodes to create lap joints

52
Q

What is oxyfuel gas welding OFW

A

Group of fusion welding operations that burn various fuels mixed with oxygen

53
Q

What is Oxyacetylene Welding OAW

A

Fusion welding performed by a high temperature flame from combustion of acetylene and oxygen

54
Q

What is diffusion welding DFW

A

coalescence is achieved by holding two surfaces together under pressure at elevated temperature (not melting)

55
Q

What is friction welding FRW

A

coalescence is achieved by heat of friction (not melting)

56
Q

What is ultrasonic welding (USW)

A

coalescence achieved by ultrasonic oscillating motion under pressure

57
Q

What is weld quality

A

concerned with acceptable weld joints that are strong and absent of defects

58
Q

What are Residual Stresses a result of

A

Rapid heating and cooling in localized regions during FW result in thermal expansion and contraction that cause residual stresses

59
Q

What do residual stresses result in

A

distortion and warpage

60
Q

Techniques to minimize warpage

A

Welding fixtures - physical restraint of parts

Heat sinks - to rapidly remove heat

Tack welding at multiple points along joint to create a rigid structure prior to seam welding

61
Q

Techniques to minimize warpage

A
  • selection of welding conditions
  • preheating base parts
  • stress relief heat treatment
62
Q

Welding defects

A

cracks
cavities
solid inclusions
incomplete fusion
Weld profile in AW

63
Q

What are cracks, what problem do they create, and why are they caused. How are they fixed

A

Cracks are fracture-type interruptions in weld or base metal. Results in a discontinuity that reduces strength. Caused by embrittlement or low ductility of weld or base metal. Must be repaired

64
Q

What are the two defect types of cavities and what are each caused by

A
  1. Porosity - small voids in weld formed by gases entrapped during solidification
  2. Shrinkage Voids - formed by shrinkage during solidification
65
Q

What is incomplete fusion

A

A weld defect in which fusion has not occurred throughout the entire cross-section of joint

66
Q

What are the 3 weld profile defects in AW

A

Undercut- portion of base metal melted away
Underfill- depression in weld below the adjacent base metal surface
Overlap- weld metal spills beyond joint onto part surface but no fusion occurs

67
Q

What are the forms of inspection and testing

A

visual inspection
Nondestructive Evaluation NDE
Destructive Testing
Mechanical Tests

68
Q

What is visual inspection? What are limitations

A

Most widely used. Human inspector visually examines for conformance and surface defects. Only surface defects are detectable

69
Q

types of nondestructive evaluation

A

Ultrasonic - high frequency soundwaves to detect cracks and inclusions

Radiographic - x-ray or gamma ray provides photos of internal flaws

Dye-penetrant and fluorescent-penetrant - to detect small cracks and cavities at part surface

Magnetic particle - iron fillings sprinkled on surface reveal defects by distorting magnetic field

70
Q

Types of destructive testing

A

mechanical tests- conventional testing methods such as tensile and shear tests

Metallurgical tests - preparation of metallurgical specimens of weldment to examine metallic structure, defects, extent and condition of heat affected zone

Manufacturing Processes (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions