Chapter 7 & 8

Front 1

how long should welding inspection be delayed for certain high-strength, low-alloy quenched and tempered steels?

Back 1

48 hours

Front 2

what are the ASTM designations for two common high-strength, low-alloy quenched and tempered steels?

Back 2

ASTM 514 & ASTM 517

Front 3

what do atoms consist of?

Back 3

a nucleus (protons and neutrons) and a cloud of encircling electrons

Front 4

what is convection?

Back 4

heat transfer in a gas or liquid by circulation of currents

Front 5

what is conduction?

Back 5

heat transfer through a substance by direct atom-to-atom contact

Front 6

what is diffusion?

Back 6

a process where the random heat-activated movement of atoms in a solid results in the movement of atoms through the solid.

Front 7

what are the AWS D1.1 requirements for preheating a certain distance away from the point of welding?

Back 7

3" in all directions (or thickness of material, whichever is greater)

Front 8

when heat is applied to metal, what are the results in dimensions and geometry?

Back 8

its dimensions increase proportionally - if the heat is applied uniformly, the increase is uniform. Distortion can occur as in Certification Manual fig. 7.14

Front 9

what are metallographs?

Back 9

optical microscopes with cameras for observing and recording the structure and composition of a metal or alloy.

Front 10

what is the difference between cementite, ferrite, martensite, austenite, bainite, and pearlite?

Back 10

ferrite,austenite, and martensite are phases of iron. bainite, and pearlite are formed by cooling austenite which produces cementite.

Front 11

what are the effects of quenching a high carbon steel rapidly? What phase and lattice structure is formed?

Back 11

it becomes harder and less ductile; martensite BCT (Body Centered Tetragonal) results

Front 12

what is ductility? What are the effects of heat on it?

Back 12

ductility refers to a material's ability to deform under tensile stress; heat increases it

Front 13

what is malleability?

Back 13

a material's ability to deform under compressive stress

Front 14

what is the minimum yield strength and minimum ultimate tensile strength of ASTM A-36 steel?

Back 14

36ksi and 58ksi

Front 15

what factors contribute to a metal's resistance to fatigue?

Back 15

fatigue is progressive and localized damage that occurs when a material is subjected to cyclic loading - its resistance can be affected by geometry, surface quality, residual stresses, size and distribution of internal defects, direction of loading, grain size, environment, and temperature.

Front 16

what are the AWS D1.1 restrictions on undercut in a cyclically-loaded structure?

Back 16

“In primary members, undercut shall be no more than 0.01 in. deep when the weld is transverse to tensile stress under any design loading condition. Undercut shall be no more than 1/32 in. deep for all other cases.” (Table 6.1)

Front 17

in what direction do metals have their highest strength?

Back 17

in the direction of the grain (the direction of rolling)

Front 18

air consists of what elements?

Back 18

78% Nitrogen, 21% Oxygen, and other gases

Front 19

what are autogenous welds?

Back 19

no filler metal

Front 20

what are the AWS D1.1 storage temperature, and atmospheric exp[exposure requirements for SMAW low-hydrogen electrodes? What are their classification numbers?

Back 20

250°F; 4 hours; ends in 5, 6, or 8

Front 21

what happens to steel when its carbon content increases?

Back 21

Steel with a low carbon content (mild steel: 0.05 – 0.15% C) has low tensile strength. As the carbon content rises, the metal becomes harder and stronger but less ductile and more difficult to weld (cast iron is > 2%C). In general, higher carbon content lowers the melting point and its temperature resistance

Front 22

what are the four main classes of stainless steel? What are Extra Low Carbon (ELC) stainless steels?

Back 22

Ferritic, Martensitic, Austenitic, and Precipitation Hardening (PH); ELC stainless steels are referred to by the letter "L" and have less than 0.03% carbon to reduce sensitizatiion

Front 23

what is carbide precipitation, and what are its effects on stainless steels?

Back 23

(also called sensitization): a common problem when welding austenitic stainless steels, chromium and carbon combine to create chromium depletion which reduces corrosion resistance

Front 24

how are surface oxides broken down when GTAW welding aluminum? What kind of current is used for this?

Back 24

GTAW in AC allows the electrode positive portion of the cycle to blast away the aluminum oxide while the electrode negative portion melts the base metal

Front 25

what are the reactive metals?

Back 25

Titanium, Zirconium, and Tantalum

Front 26

rapid cooling of austenitic steel results in a hard brittle structure known as what?

Back 26

martensite

Front 27

very slow cooling of austenitic steel may result in a soft, ductile, layered structure known as what?

Back 27

pearlite

Front 28

when rapid cooling produces martensitic structure, what non-austenitizing heat treatment may improve its ductility?

Back 28

tempering

Front 29

what heat treatment is characterized by holding the part at the austenitizing temperature for some time and then slow cooling in the furnace?

Back 29

annealing

Front 30

what heat treatment is characterized by holding the part at the austenitizing temperature for some time and then slow cooling in the air

Back 30

normalizing

Front 31

what is the effect of increasing steel's carbon content on its likelihood of cracking (raise, lower, no effect)?

Back 31

raise

Front 32

the property that describes the ability of a metal to resist some applied load is:

Back 32

strength

Front 33

the point at which a metal's behavior changes from elastic to plastic is called:

Back 33

yield strength

Front 34

the property of metals that describes their resistance to indentation is called:

Back 34

hardness

Front 35

list 5 properties that a tensile test measures

Back 35

Ultimate Tensile Strength (UTS), yield strength, ductility, percent elongation, percent reduction in area

Front 36

list all the hardness tests

Back 36

Brinell, Rockwell, and microhardness (Vickers, Knoop)

Front 37

list these hardness tests in decreasing order of indenter size: Rockwell, microhardness, Brinell

Back 37

Brinell, Rockwell, microhardness

Front 38

what hardness tests are referred to as "microhardness" tests?

Back 38

Vickers and Knoop

Front 39

what type of test uses a weighted pendulum that strikes a notched test specimen?

Back 39

Charpy Impact Test

Front 40

what describes a metal's ability to absorb energy?

Back 40

toughness

Front 41

1 kilogram is approximately how many pounds?

Back 41

2.2

Front 42

1 inch is how many millimeters?

Back 42

25.4

Front 43

what percent elongation occurs when the gauge marks go from 4 in. to 6 in.?

Back 43

50%

Front 44

tensile strength is calculated by dividing what two quantities?

Back 44

tensile load divide by cross-section area

Front 45

the property of metal describing its freedom from imperfections is:

Back 45

soundness

Front 46

if a metal exhibits a great deal of elongation before failing a tensile test it is said to have high:

Back 46

ductility

Front 47

what test uses a specimen with a carefully radiused v-notch?

Back 47

Charpy Impact Test

Front 48

identify the following prefixes (and their symbols): milli, micro, centi, kilo, mega

Back 48

milli (m): one thousandth (0.001); micro (μ): one millionth (0.0001); centi (c): one hundredth (0.01); kilo (k): one thousand (1,000); mega (M): one million (1,000,000)

Front 49

what is annealing?

Back 49

A heat treatment performed by heating the material and allowing it to cool slowly - it becomes softer and more ductile. annealing processes include, "normalizing" & "stress relief"

Front 50

what is quenching?

Back 50

A heat treatment used to harden a metal. It is heated to the austenitic phase and then quickly cooled using air, oil, water, brine, etc.. A portion will become martensite.

Front 51

what is tempering?

Back 51

reheating quenched steel to a temperature below the austenitizing temperature then cooling - which restores ductility, but reduces hardness.

Front 52

what is stress relief?`

Back 52

heating to a suitable temperature, holding long enough to reduce residual stresses, and then cooling slowly enough to minimize the development of new residual stresses.

Front 53

what are the effects of, and some sources of hydrogen in welding?

Back 53

hydrogen can diffuse into the material causing stress (also called "underbead" or "delayed") cracks; sources include moisture and organic compounds such as grease or oil.

Front 54

what is the maximum temperature allowed by AWS D1.1 for heat straightening quenched and tempered steels? For other steels?

Back 54

1100°F, 1200°F

Front 55

what are the cell structures FCH, HCP, FCC, BCT, and BCT, and how many atoms are in each?

Back 55

BCC: Body Centered Cubic has 9 atoms per cell; FCC: Face Centered Cubic has 14 atoms per cell; HCP: Hexagonal Close Packed has 17; BCT: Body Centered Tetragonal has 9 atoms per cell; FCH?

Front 56

identify the following prefixes (and their symbols): milli, micro, centi, kilo, mega

Back 56

milli (m): one thousandth (0.001); micro (μ): one millionth (0.0001); centi (c): one hundredth (0.01); kilo (k): one thousand (1,000); mega (M): one million (1,000,000)

Front 57

what is stress?

Back 57

The force per unit area on a body that tends to cause it to deform

Front 58

what is strain?

Back 58

A measure of the extent to which a body is deformed when it is subjected to a stress

Front 59

what are three types of stress?

Back 59

tensile, compressive, and shear

Front 60

identify the ram, die, and plunger, and mandrel in a guided bend test

Back 60

ram = plunger = mandrel (male); die (female)

Front 61

what is "modulus of elasticity"?

Back 61

the slope of the line in a stress-strain diagram from the origin to the yield point; units are psi; measures "stiffness"

Front 62

what is "Young's Modulus"?

Back 62

the same as "modulus of elasticity" in the cases of compression and tension

Front 63

what are the characteristic stress-strain curves for steel and cast iron?

Back 63

figs 8.4 & 8.5, cert. manual

Front 64

what are the differences between transverse root- and face-bend tests and side-bend tests? When are they used?

Back 64

root and face bends have the same size test specimen, but the convex side is different, side bend tests are 6" x 3/8" x (material thickness). They are all Destructive Tests

Front 65

what are the dimensions of the specimens (length, width, and thickness) for transverse root- and face-bend tests and side-bend tests?

Back 65

root and face: 6" x 3/2" x 3/8"; side: 6" x (thickness of material) x 3/8"

Front 66

what are the Visual Testing (VT) acceptance criteria for welder certification in AWS D1.1?

Back 66

1) no CRACKS, 2) CRATERS filled, 3) UNDERCUT ≤ 1/32", 4) groove welds' REINFORCEMENT ≤ 1/8" and no UNDERFILL, 5) fillet welds' LEG SIZE sizes and PROFILES correct 6) no ARC STRIKES outside weld zone (4.8.1.1 & 4.8.1.2)

Front 67

what are the Destructive Testing (DT) acceptance criteria for welder certification in AWS D1.1?

Back 67

on the convex face of bend specimen: 1) any discontinuity must be ≤ 1/8", 2) the sum of discontinuities that are > 1/32" cannot exceed 3/8", 3) corner cracks must be ≤ 1/4" (except fusion type discontinuities - then 1/8") 4.8.3.3

Front 68

when is it appropriate to use a Vickers hardness test?

Back 68

the indenter is smaller than Brinell or Rockwell, so it can test smaller areas (for example, the HAZ), and leaves less damage to the specimen. Also, whenever the PQR requires it

Front 69

compare the indenter shapes for the various hardness tests

Back 69

Brinell: sphere; Rockwell: sphere or cone; Vickers: square pyramid; Knoop: diamond pyramid

Front 70

name the three general types of soundness tests

Back 70

bend, nick-break, and fillet weld break

Front 71

what soundness test is used almost exclusively by the pipeline industry?

Back 71

nick-break test

Front 72

name the most commonly used toughness test

Back 72

Charpy Impact Test (sometimes called Izod)

Front 73

for less ductile metals, which method is used to determine yield strength?

Back 73

offset technique

Front 74

order these cooling methods for steel from slowest to fastest: brine quench, furnace anneal, normalize, oil quench, water quench

Back 74

furnace anneal, normalize, oil quench, water quench, brine quench

Front 75

how far should a crack be removed?

Back 75

2" beyond each end, after finding the end using acid etching, MT, PT etc.

Front 76

what crack size is allowed in {statically loaded, cyclically loaded, tubular} connections?

Back 76

none

Front 77

must all craters be filled to the weld size?

Back 77

yes (except for the ends of intermittent fillet welds, outside of their effective length)

Front 78

how much smaller than spec (underrun) can a continuous fillet weld be ?

Back 78

weld spec size: ≥ 5/16" : underrun ≤ 1/8"

weld spec size = 1/4" : underrun ≤ 3/32"
weld spec size < 1/4" : underrun ≤ 1/16"

Front 79

in statically loaded non-tubular connections, what is the allowable undercut?

Back 79

"for material less than 1 in. thick, undercut shall not exceed 1/32 in., with the following exception: undercut shall not exceed 1/16 in. for any accumulated length up to 2 in. in any 12 in.. For material greater than 1 in. thick, undercut shall not exceed 1/16 in. for any length of weld"

Front 80

for cyclically loaded and tubular connections, what is the allowable undercut?

Back 80

"In primary members, undercut shall be no more than 0.01 in. deep when the weld is transverse to tensile stress under any design loading conditions. Undercut shall be no more than 1/32 in. deep for all other cases."

Front 81

what type of weld joint can have no porosity?

Back 81

"CJP groove welds in butt joints transverse to the direction of computed tensile stress"

Front 82

name 3 methods of removing weld stresses

Back 82

thermal treatment, peening, vibratory stress relief

Front 83

If a 1200 pound load is placed on a specimen having a cross-sectional area of 6 square inches, what is the tensile strength?

Back 83

200psi

Front 84

what are the formulas for the area of a rectangle and circle?

Back 84

rectangle: A = Length x Width
circle: A = Pi x Radius x Radius (Pi is approximately 3.14)

Front 85

A tensile test specimen's original cross-section measures 10 square inches, and is reduced to 4 square inches. What percent reduction is this?

Back 85

60%

Front 86

how much convexity is allowed in a fillet weld?

Back 86

5/16" < weld face < 1" then convexity ≤ 1/8"

weld face ≤ 5/16" then convexity ≤ 1/16"
weld face > 1" then convexity ≤ 3/16"

Front 87

how much reinforcement is allowed for a groove weld in a butt joint?

Back 87

1/8"

Front 88

in statically loaded non-tubular connections, how much porosity does AWS D1.1 allow?

Back 88

"the sum of the visible piping porosity 1/32 in. or greater shall not exceed 3/8 in. in any linear inch of weld, and shall not exceed 3/4 in. in any 12 in. length of weld" (CJP groove weld in butt joint transverse to tension allows no porosity)

Front 89

for cyclically loaded and tubular connections, what amount of porosity does AWS D1.1 allow?

Back 89

the frequency of piping porosity shall not exceed one per 4 in. of length, and the maximum diameter shall not exceed 3/32 in.

Front 90

what is the minimum radius of a reentrant corner?

Back 90

1 in.

Front 91

what are the dimensions required for a weld access hole (cope hole)?

Back 91

length from toe of weld prep at least 1.5 x (thickness of material in which hole is cut). height must be adequate for welding etc., but not less than thickness of material.

Front 92

what is the minimum fillet weld size?

Back 92

1/8" for material ≤ 1/4" thick unless the weld reinforces a groove weld. (see Table 5.8)

Front 93

what is the joint designation for a single bevel groove weld in a T-joint using SMAW?

Back 93

TC-U4a

Front 94

what is the joint designation for a CJP single V-groove weld in a butt joint applied with SMAW?

Back 94

BU-2a

Front 95

what are the dimensions of a pull-test specimen?

Back 95

the reduced portion should measure 3/4 " x (thickness of material) - fig. 4.14

Front 96

what is the Ultimate Tensile Strength (UTS) for a all-weld-metal tension specimen which had a diameter of 0.508" and failed at 18,700 pounds (answer to the nearest pound)?

Back 96

92,262 psi

Front 97

What does the "S" in FCAW-S and GMAW-S stand for?

Back 97

FCAW-S: (Flux Cored Arc Welding) Self Shielded
GMAW-S: (Gas Metal Arc Welding) Short Circuit Arc

Front 98

What are the radii of the plunger tip and die bottom used to bend-test A-36 specimens?

Back 98

The plunger tip radius is 3/4"
The die bottom radius is 1 3/16"

Front 99

What is peening, what is it used for, and when should it not be used?

Back 99

Peening is the mechanical distortion of the weld bead used for stress relief. It should not be done on the root pass or final layers of a weld.

Front 100

when the Carbon Equivalent (CE) of a steel exceeds 0.40%, what is recommended? When it exceeds 0.60%?

Back 100

Preheating to 200-400°F and 400-700°F respectively. In addition low-hydrogen electrodes and postweld heat treatmenst (PWHT) may be required

Front 101

How can the Brinell Hardness Number (BHN) be used to estimate the strength of steel?

Back 101

by multiplying by 500

Front 102

What is another name for "impact strength"?

Back 102

notch toughness

Front 103

Which of these qualities are proportional to one another: {hardness, ductility, weldability, strength}

Back 103

strength and hardness