What does the 'cold-work factor W' represent as defined in Section 2-3?

Correct answer: The reduction in area from the original area, expressed as a ratio.

Explanation

This question tests the definition of the cold-work factor (W), a fundamental parameter used to quantify the amount of plastic deformation a material has undergone, which is then used to predict the resulting changes in mechanical properties like yield and ultimate strength.

Other questions

Question 1

In the context of a standard tensile test, what does the constant of proportionality E, which is the slope of the linear part of the stress-strain curve, represent?

Question 2

What is the term for the capacity of a material to absorb energy within its elastic range, which is equal to the area under the stress-strain curve up to the elastic limit?

Question 3

According to the Unified Numbering System (UNS) for steels, what does the designation G10400 indicate?

Question 4

Which manufacturing process is described as a basic, low-cost method suitable for large quantities with practically no limit to size, shape, or complexity, but is the most difficult for steel due to its high melting temperature?

Question 5

What is the primary purpose of the heat treatment process known as tempering on a fully hardened steel specimen?

Question 6

An annealed AISI 1018 steel with an ultimate strength (Su) of 49.5 kpsi, a yield strength (Sy) of 32.0 kpsi, and a strain-strengthening coefficient (sigma_0) of 90 kpsi is given 15 percent cold work. What is the new yield strength (S'y)? The strain-strengthening exponent (m) is 0.25.

Question 7

What is the primary effect of adding chromium as an alloying element to steel?

Question 8

In the context of material properties, what is the Bauschinger effect?

Question 9

Using the approximate relationship for steels, what is the estimated ultimate strength (Su) in kpsi for a steel with a Brinell hardness (HB) of 300?

Question 10

What is the key difference between thermoplastics and thermosets?

Question 11

What happens to the engineering stress-strain curve for a ductile material after the ultimate strength point (point u) is reached?

Question 12

For a material that exhibits an engineering stress-strain curve with a peak at the ultimate strength, the strain-strengthening exponent (m) is equal to what value?

Question 13

What is the ASTM numbering system for cast iron based on?

Question 14

Which type of cast iron contains graphite in the form of spheroids, has a high modulus of elasticity, and exhibits ductile properties in its as-cast condition?

Question 15

What is the primary characteristic of aluminum and its alloys that gives them a high strength-to-weight ratio compared to steel?

Question 16

A material has a yield strength (Sy) of 50 kpsi and a Young's modulus (E) of 20 Mpsi. What is its approximate modulus of resilience (uR)?

Question 17

What is the primary reason that cold working (such as cold drawing) increases the yield strength of a steel bar?

Question 18

Which of the following nonferrous metals is the lightest of all commercial metals, with a density about two-thirds that of aluminum, but has a yield point that is significantly reduced at the temperature of boiling water?

Question 19

In material selection using Ashby charts, what does the material index M = E^(1/2)/ρ represent when designing for a light, stiff, end-loaded cantilever beam?

Question 20

What is the purpose of the heat-treating process known as normalizing for steel parts?

Question 21

Which copper-base alloy is particularly noted for its resistance to fatigue and corrosion, high tensile strength, and high capacity to absorb energy, making it very useful as a spring material?

Question 22

What is the defining characteristic of composite materials compared to metallic alloys?

Question 23

A gray cast iron part has a Brinell hardness number (HB) of 220. Using the minimum strength relationship defined by the ASTM, estimate its ultimate strength (Su) in kpsi.

Question 25

Which of the following processes involves heating a metal above its recrystallization temperature before working it?

Question 26

What is the primary advantage of using a powder-metallurgy process for manufacturing parts?

Question 27

What does a material's 'modulus of toughness' represent?

Question 28

In the UNS designation for aluminum alloys, what does the prefix 'A9' signify?

Question 29

What is the ductile-brittle transition temperature, as observed in a Charpy impact test?

Question 30

For a material that has undergone cyclic loading, what is a stable cyclic hysteresis loop?

Question 31

An annealed AISI 1018 steel has an ultimate strength (Su) of 49.5 kpsi. If it is given 25 percent cold work, what is the new ultimate strength (S'u)?

Question 32

Which alloying element, when added to steel, is most effective in producing desirable oil-hardening and air-hardening properties due to its effect of substantially lowering the transformation point?

Question 33

What is the key structural difference between gray cast iron and malleable cast iron?

Question 34

What is the approximate modulus of elasticity for aluminum alloys?

Question 35

Which of these processes is NOT considered a hot-working process?

Question 36

What is the equivalent true strain (ε̃) for a material that has undergone 30 percent cold work (W)?

Question 37

How is the true stress (σ̃) related to the engineering stress (σ) and engineering strain (ε) up to the point of necking?

Question 38

What is the primary characteristic of a stable cyclic stress-strain curve for a cyclic softening material like 2024-T4 aluminum?

Question 39

To ensure a certain cast iron part always meets or exceeds ASTM No. 25 specifications, which requires a minimum ultimate strength of 25 kpsi, what is the minimum Brinell hardness (HB) that should be specified?

Question 40

Iron-base alloys containing at least what percentage of chromium are called stainless steels?

Question 41

What is yield strength (Sy) often defined by when a material does not have an obvious yield point on its stress-strain diagram?

Question 42

According to Section 2-3, what is the new ultimate strength (S'u) of a material with an original ultimate strength (Su) after it has undergone a cold-work factor of W?

Question 43

Which statement accurately describes the properties of chromium-nickel stainless steels?

Question 44

What is the primary purpose of adding lead to brass alloys?

Question 45

What is the term for the continuous deformation of a material under a constant load over long periods, especially at elevated temperatures?

Question 46

What is a major disadvantage of the powder metallurgy process?

Question 47

What is the relationship between true strain (ε̃) and engineering strain (ε) up to the ultimate tensile strength?

Question 48

In the Ramberg-Osgood relationship, ε̃ = (σ̃/E) + (σ̃/σ0)^(1/m), what does the term (σ̃/E) represent?

Question 49

For a steel with a yield strength of 80 kpsi and an ultimate strength of 100 kpsi, what is its approximate modulus of toughness (uT) if the strain at fracture (εf) is 0.15?

Question 50

Why is it generally not necessary to apply a stress-concentration factor for a ductile material under static loading?