A3 Flashcards
What is the primary consideration in selecting materials for piping applications?
A. The ability to resist chemical reactions
B. Suitability for flow medium and operating conditions
C. Cost-effectiveness and availability
D. Compliance with environmental regulations
Suitability for flow medium and operating conditions
What operational variables must piping materials resist for long-term service?
A. Pressure and velocity fluctuations C. Temperature and corrosion
B. Thermal and mechanical cycling D. Creep and oxidation resistance
Thermal and mechanical cycling
Which factor related to the operating environment of the pipe is critical during material selection?
A. The weight of the surrounding structure
B. Degradation due to corrosion or erosion
C. Thermal conductivity of the surrounding material
D. Electrical conductivity of the pipe material
Degradation due to corrosion or erosion
Why is compliance with design and construction codes such as the ASME B31 Pressure Piping Code important?
A. It ensures economical material selection.
B. It specifies material degradation issues.
C. It assures safe operation under specified conditions.
D. It prevents oxidation and thermal cycling issues.
It assures safe operation under specified conditions
What is one limitation of designing piping systems strictly based on ‘the Code’?
A. It increases fabrication complexity.
B. It overlooks environmental and material degradation issues.
C. It prohibits the use of carbon and low alloy steels.
D. It ignores thermal and mechanical stresses.
It overlooks environmental and material degradation issues
What is the smallest repeating building block of a crystalline structure in metals called?
A. Space lattice C. Unit cell
B. Crystal lattice D. Atomic grid
Unit cell
Which two unit cell forms are observed in iron and iron-based alloys?
A. Hexagonal close-packed (HCP) and cubic lattice
B. Body-centered cubic (BCC) and face-centered cubic (FCC)
C. Tetragonal and orthorhombic structures
D. Body-centered tetragonal (BCT) and face-centered orthorhombic (FCO)
Body-centered cubic (BCC) and face-centered cubic (FCC)
What distinguishes the face-centered cubic (FCC) structure from the body-centered cubic (BCC) structure?
FCC has atoms at the cube corners and the center of each face
What is the fundamental atomic motion involved in plasticity?
A. Atoms vibrating in place within the lattice
B. Atoms sliding across planes in the crystal structure
C. Atoms rearranging to form new unit cells
D. Atoms breaking free from the lattice
Atoms sliding across planes in the crystal structure
What causes certain metals, such as iron, to change their crystal structure?
A. Variations in temperature C. Application of mechanical stress
B. Exposure to chemical reactions D. Changes in pressure
Variations in temperature
What is the main difference in the atomic structure of plastics compared to metals?
A. Plastics lack a predictable atomic structure.
B. Plastics are formed by carbon-hydrogen chains (monomers to polymers).
C. Plastics have a crystalline atomic structure similar to ceramics.
D. Plastics have no molecular weight.
Plastics are formed by carbon-hydrogen chains (monomers to polymers)
What is a key limitation of plastics compared to metals in engineering applications?
A. Higher impact strength
B. Poor chemical, thermal, and aging stability
C. Greater strength per unit weight
D. Limited versatility in construction
Poor chemical, thermal, and aging stability
How do ceramic materials differ from metals in terms of atomic behavior?
A. Ceramics have random atomic arrangements like glasses.
B. Ceramics exhibit more plasticity than metals.
C. Ceramics have rigid, predictable atomic structures but lack plasticity.
D. Ceramics are composed entirely of polymers.
Ceramics have rigid, predictable atomic structures but lack plasticity
Into which three categories do the properties of engineering materials fall?
A. Chemical, mechanical, and physical
B. Atomic, structural, and electronic
C. Structural, mechanical, and electrical
D. Thermal, electronic, and physical
Chemical, mechanical, and physical
What is the process of adding secondary elements to metals to improve or modify their behavior called?
A. Alloying C. Quenching
B. Tempering D. Refining
Alloying
What are interstitial alloying elements?
A. Atoms that substitute parent metal atoms in the atomic matrix
B. Atoms smaller than the parent metal atoms that fit into spaces in the lattice
C. Atoms that improve ductility in the metal
D. Atoms larger than the parent metal atoms that replace the lattice structure
Atoms smaller than the parent metal atoms that fit into spaces in the lattice
What is the effect of adding alloying elements to a pure metal’s atomic matrix?
A. It reduces the strength and increases ductility.
B. It creates a smoother surface for better conductivity.
C. It increases the strength by straining the atomic lattice.
D. It lowers the melting point of the material.
It increases the strength by straining the atomic lattice
Which of the following is an example of substitutional alloying?
A. Carbon added to iron, creating steel
B. Zinc replacing copper atoms, creating brass
C. Oxygen atoms forming oxides with metals
D. Hydrogen atoms fitting into a metal lattice
Zinc replacing copper atoms, creating brass
What is one reason elements are added to metals during alloying?
A. To reduce the strength of the metal
B. To improve corrosion or oxidation resistance
C. To remove impurities from the material
D. To decrease the cost of production
To improve corrosion or oxidation resistance
What are the primary elements always present in carbon steels?
A. Carbon, manganese, phosphorous, sulfur, and silicon
B. Hydrogen, oxygen, nitrogen, and chromium
C. Nickel, copper, molybdenum, and tin
D. Carbon, chromium, silicon, and nickel
Carbon, manganese, phosphorous, sulfur, and silicon
What is the effect of adding significant amounts of carbon to steel?
A. Increased weldability and formability
B. Increased strength and hardness but reduced formability and weldability
C. Improved corrosion resistance and oxidation stability
D. Reduced manufacturing cost and increased machineability
Increased strength and hardness but reduced formability and weldability
What is the purpose of adhering to material specification limits in piping design?
A. To reduce the cost of raw materials
B. To ensure reliability, predictability, and repeatability of material behavior
C. To simplify the alloying process for manufacturers
D. To increase the flexibility of design specifications
To ensure reliability, predictability, and repeatability of material behavior
What is a ‘ladle analysis’ in the context of material testing?
A. A test of the metal’s behavior under heat treatment
B. A chemical analysis performed on a sample of molten metal
C. A test of the final product’s weldability and formability
D. A method of checking corrosion resistance in a finished product
A chemical analysis performed on a sample of molten metal
How are mechanical properties of metals defined?
A. By the chemical composition of the metal
B. By the material’s response to applied force
C. By the thermal behavior of the material
D. By the electrical conductivity of the metal
By the material’s response to applied force
What are the two general categories of mechanical properties?
A. Strength and thermal stability C. Strength and ductility
B. Ductility and corrosion resistance D. Toughness and conductivity
Strength and ductility
What does the modulus of elasticity (Young’s Modulus) measure?
A. The ratio of stress to strain in the elastic range
B. The toughness of the material
C. The resistance to chemical changes under stress
D. The maximum force a material can withstand
The ratio of stress to strain in the elastic range
In which range does Hooke’s law apply to material behavior?
A. Plastic range C. Yield range
B. Elastic range D. Failure range
Elastic range
What is the primary purpose of a tension test in material testing?
A. To measure a material’s thermal conductivity
B. To determine the modulus of elasticity and other strength properties
C. To assess the material’s corrosion resistance
D. To analyze the chemical composition of the material
To determine the modulus of elasticity and other strength properties
What happens to a material when it is loaded beyond the elastic behavior point?
A. The material fractures immediately.
B. The material begins to deform in a plastic manner.
C. The material’s modulus of elasticity increases.
D. The material’s cross-sectional area remains constant.
The material begins to deform in a plastic manner
What is the most common method used to determine yield strength according to ASTM?
A. Stress-strain curve analysis C. Elastic modulus calculation
B. 0.2 percent offset method D. Ultimate tensile strength method
0.2 percent offset method
How is yield strength calculated using the 0.2 percent offset method?
A. By dividing the maximum load by the final cross-sectional area
B. By finding the point where the material fractures
C. By dividing the load at the intersection point of the offset line by the original
cross-sectional area
D. By calculating the ratio of stress to strain in the elastic range
By dividing the load at the intersection point of the offset line by the original cross-sectional area
What is ultimate tensile strength?
A. The maximum stress a material can endure before plastic deformation
B. The maximum applied load divided by the original cross-sectional area
C. The point where elastic deformation stops
D. The load at which the specimen fractures
The maximum applied load divided by the original cross-sectional area
What causes the specimen to stop carrying additional load during the ultimate tensile strength test?
A. The material reaches its elastic limit.
B. Specimen thinning reduces the load-carrying cross-section.
C. The material transforms from plastic to elastic behavior.
D. The strain rate becomes constant.
Specimen thinning reduces the load-carrying cross-section
What does percent elongation measure in a test specimen?
A. The material’s resistance to deformation
B. The material’s ability to return to its original shape
C. The stretch of the specimen as a percentage of its original length
D. The change in hardness of the material
The stretch of the specimen as a percentage of its original length
What does the percent reduction of area indicate?
A. The decrease in material length during testing
B. The increase in cross-sectional area after deformation
C. The decrease in the cross-sectional area after deformation
D. The change in hardness of the material after testing
The decrease in the cross-sectional area after deformation
What do hardness tests primarily measure?
A. The ability of a material to resist tensile stress
B. The surface resistance of a material to indentation
C. The ductility of a material under strain
D. The material’s reduction of cross-sectional area
The surface resistance of a material to indentation
Which of the following is NOT a standard test for measuring hardness?
A. Rockwell Hardness Test C. Poisson’s Ratio Test
B. Brinell Hardness Test D. Vickers Hardness Test
Poisson’s Ratio Test
What is the primary measure of a material’s toughness?
A. Its ability to resist corrosion
B. Its resistance to brittle fracture when loaded rapidly
C. Its elongation during testing
D. Its hardness under compression
Its resistance to brittle fracture when loaded rapidly
What does the Charpy Impact test measure?
A. The tensile strength of the material
B. The toughness of a material by measuring energy loss during fracture
C. The elongation of a specimen under stress
D. The reduction in area of a specimen
The toughness of a material by measuring energy loss during fracture
What does fatigue resistance measure in a metal?
A. The ability of a metal to resist corrosion under repeated loading
B. The ability to resist crack initiation and propagation under cyclic loading
C. The material’s hardness under high temperatures
D. The strength of the material at low temperatures
The ability to resist crack initiation and propagation under cyclic loading
Which of the following is true about the endurance limit of ferritic steels?
A. They exhibit a finite number of cycles to failure with decreasing load
B. They exhibit no cycles to failure when exposed to constant stress
C. They exhibit an infinite number of cycles to failure without causing fracture at a
certain load range
D. They fail immediately after the first cycle under cyclic load
They exhibit an infinite number of cycles to failure without causing fracture at a certain load range
What is the main purpose of performing tensile tests at elevated temperatures?
A. To determine the material’s hardness at high temperatures
B. To characterize yield and ultimate tensile properties at temperatures above room
temperature
C. To measure the impact resistance of a material at elevated temperatures
D. To test the material’s resistance to corrosion at high temperatures
To characterize yield and ultimate tensile properties at temperatures above room temperature
What is the definition of creep in materials?
A. A material’s immediate deformation under load at room temperature
B. The time-dependent deformation of a material under load at elevated
temperatures
C. The resistance of a material to fracture under high stress
D. The increase in a material’s strength when exposed to high temperatures
The time-dependent deformation of a material under load at elevated temperatures
Which of the following is NOT a physical property of metals?
A. Density C. Ultimate tensile strength
B. Thermal conductivity D. Specific heat
Ultimate tensile strength
What does the coefficient of thermal conductivity (k) measure?
A. The ability of a material to resist heat flow
B. The energy required to raise the temperature of a material
C. The ability of a material to transfer heat energy from a high-temperature source
to a low-temperature point
D. The resistance of a material to mechanical stress
The ability of a material to transfer heat energy from a high-temperature source to a low-temperature point
How does the thermal conductivity of carbon steel change with increasing temperature?
A. It increases C. It remains constant
B. It decreases D. It fluctuates irregularly
It decreases
What is the definition of thermal expansion?
A. The increase in heat flow through a material with temperature
B. The ratio of mass to volume of a material
C. The ratio of change in length per degree of temperature to the original length at a
standard temperature
D. The measure of energy required to increase the material’s temperature
The ratio of change in length per degree of temperature to the original length at a standard temperature
Which physical property describes the heat required to raise the temperature of a unit weight of material by one degree?
A. Specific heat C. Thermal conductivity
B. Density D. Thermal expansion
Specific heat
What are the individual crystals formed during metal solidification called?
A. Atoms C. Nuclei
B. Grains D. Lattices
Grains
What is the process called when strained grains are replaced with unstrained grains during heat treatment?
A. Solidification C. Cold working
B. Recrystallization D. Grain refinement
Recrystallization
What happens to heavily strained materials at elevated temperatures sufficient to cause recrystallization?
A. They maintain their strain indefinitely
B. They develop distorted grains
C. They form new, small, unstrained grains
They form new, small, unstrained grains
What is the process called when strained grains are replaced with unstrained grains during heat treatment?
A. Solidification C. Cold working
B. Recrystallization D. Grain refinement
Recrystallization
Recrystallization is a key process in materials science that allows for the recovery of ductility in deformed metals.
What happens to heavily strained materials at elevated temperatures sufficient to cause recrystallization?
They form new, small, unstrained grains
This process helps restore ductility and mechanical properties to the material.
What property allows certain steels to be strengthened through heat treatment?
A. Ductility C. Toughness
B. Hardenability D. Grain refinement
Hardenability
Hardenability is a measure of a steel’s ability to harden in depth when subjected to heat treatment.
What is the name of the test used to evaluate the hardenability of steel?
A. Rockwell Hardness Test C. Jominy End Quench Test
B. Charpy Impact Test D. Creep-Rupture Test
Jominy End Quench Test
This test involves quenching a heated steel sample to determine its hardenability profile.
What is the primary component used to reduce iron ore in a blast furnace?
A. Limestone C. Slag
B. Coke D. Graphite
Coke
Coke serves as both a fuel and a reducing agent in the smelting process.
Which form of cast iron is known for its high hardness and brittleness due to the presence of iron carbide (Fe3C)?
A. Gray iron C. Ductile iron
B. White cast iron D. Malleable cast iron
White cast iron
White cast iron is characterized by its hard and brittle structure, making it suitable for specific applications.
How does gray cast iron derive its name?
A. Its fracture surface appears silvery
B. Its structure is made up of nodular graphite
C. Its fracture surface is gray due to graphite flakes
D. It contains no carbon
Its fracture surface is gray due to graphite flakes
The presence of graphite gives gray cast iron its distinctive appearance and properties.
Which property distinguishes ductile iron from gray cast iron?
A. High graphite flake content
B. Superior mechanical properties due to spheroidal graphite
C. Presence of cementite throughout the structure
D. Better fluidity in the molten state
Superior mechanical properties due to spheroidal graphite
Ductile iron, also known as nodular iron, has improved ductility and strength compared to gray iron.
Which process is primarily used to refine pig iron by oxidizing impurities and excess carbon to produce steel?
A. Basic Oxygen Process (BOP) C. Basic Open-Hearth Process
B. Electric Furnace Process D. Cupola Furnace Process
Basic Oxygen Process (BOP)
This process is widely used in modern steelmaking for its efficiency and effectiveness.
What is the primary difference between steel and cast iron in terms of carbon content?
A. Steel has more than 2.0 weight percent carbon, while cast iron has less.
B. Steel has less than 2.0 weight percent carbon, while cast iron has more.
C. Both have the same carbon content, but differ in other alloying elements.
D. Steel contains no carbon, while cast iron contains carbon.
Steel has less than 2.0 weight percent carbon, while cast iron has more
This difference in carbon content significantly affects their mechanical properties.
What is the crystal structure of alpha iron (ferrite) at room temperature?
A. Face-centered cubic (FCC) C. Hexagonal close-packed (HCP)
B. Body-centered cubic (BCC) D. Amorphous
Body-centered cubic (BCC)
The BCC structure of ferrite contributes to its properties, such as ductility.
What phase transformation occurs at 910°C in pure iron?
A. Alpha iron to delta iron C. Gamma iron to delta iron
B. Alpha iron to gamma iron D. Delta iron to liquid iron
Alpha iron to gamma iron
This transformation is critical in the iron-carbon phase diagram.
What is the term used for the changes in atomic structure during heating and cooling in pure iron?
A. Critical temperature shifts C. Allotropic changes
B. Phase transformations D. Thermal expansion
Allotropic changes
Allotropic changes are essential for understanding the behavior of iron during thermal treatments.
Which of the following is true about ferrite in steel?
A. It is a mixture of alternating plates of cementite and ferrite
B. It contains a small amount of carbon and is soft, ductile, and relatively weak
C. It forms only at elevated temperatures
D. It is hard and brittle
It contains a small amount of carbon and is soft, ductile, and relatively weak
Ferrite’s properties make it a valuable phase in steel for certain applications.
What is the effect of increasing the carbon content in steel?
A. Increases ductility and toughness
B. Decreases air-hardening tendencies
C. Increases ultimate strength and hardness, but may lower ductility and toughness
D. Increases electrical conductivity
Increases ultimate strength and hardness, but may lower ductility and toughness
The relationship between carbon content and mechanical properties is a fundamental concept in metallurgy.
What is the effect of phosphorus in steel?
A. Improves shock resistance and ductility
B. Improves machineability but lowers shock resistance and ductility
C. Increases the tensile strength without affecting brittleness
Improves machineability but lowers shock resistance and ductility
Phosphorus is often added to improve machinability, but care must be taken regarding its negative effects.
What role does silicon play in steel alloying?
A. Increases brittleness and reduces oxidation resistance
B. Decreases electrical resistivity and increases thermal conductivity
C. Acts as a deoxidizing agent, increasing tensile strength and resistance to
oxidation
D. Lowers creep rupture strength without affecting brittleness
Acts as a deoxidizing agent, increasing tensile strength and resistance to oxidation
Silicon is beneficial in controlling the quality of steel during production.
How does manganese affect steel properties?
A. Increases the critical cooling rate for hardening
B. Improves hot-working characteristics by combining with sulfur
C. Decreases the tensile strength and reduces hardness
D. Improves weldability by increasing thermal conductivity
Improves hot-working characteristics by combining with sulfur
Manganese is essential for enhancing the mechanical properties of steel.
What is the effect of adding nickel to alloy steels?
A. Decreases toughness and strength
B. Reduces the critical cooling rate, making steels harder
C. Increases the brittleness of the steel
D. Lowers impact and fatigue resistance
Reduces the critical cooling rate, making steels harder
Nickel is a valuable alloying element that enhances toughness and strength.
What is the role of molybdenum in steel?
A. Reduces hardness and increases brittleness
B. Forms stable carbides that contribute to matrix strengthening in long-term creep
service
C. Decreases oxidation resistance at elevated temperatures
D. Improves weldability but reduces strength
Forms stable carbides that contribute to matrix strengthening in long-term creep service
Molybdenum is often used in high-performance steel applications.
How does vanadium affect steel properties?
A. It reduces the grain structure and decreases strength
B. It dissolves in ferrite, providing strength and toughness, and results in a finer
grain structure
C. It improves electrical conductivity without affecting the strength
D. It weakens the steel by reducing hardness
It dissolves in ferrite, providing strength and toughness, and results in a finer grain structure
Vanadium is effective in refining the grain size of steel.
What is the primary use of aluminum in steel alloying?
A. Increases sulfur content for better machinability
B. Acts as a deoxidizer and controls grain size
C. Increases the carbon content for better hardenability
D. Reduces the melting point of steel
Acts as a deoxidizer and controls grain size
Aluminum is commonly used in steelmaking to improve quality and performance.
What is the effect of copper on steel alloys?
A. Improves resistance to atmospheric corrosion and increases yield strength, but excessive copper harms elevated temperature performance
B. Increases the hardness and reduces strength at elevated temperatures
C. Reduces corrosion resistance and decreases yield strength
D. Improves thermal conductivity but reduces yield strength
Improves resistance to atmospheric corrosion and increases yield strength, but excessive copper harms elevated temperature performance
Copper is beneficial in certain environments but can cause issues at high temperatures.
Which of the following defines low carbon steels?
A. Carbon content between 0.25 and 0.50 percent
B. Carbon content between 0.05 and 0.25 percent
C. Carbon content greater than 0.50 percent
D. Carbon content between 1.0 and 2.0 percent
Carbon content between 0.05 and 0.25 percent
Low carbon steels are characterized by their ductility and weldability.
What distinguishes alloy steels from plain carbon steels?
A. The addition of one or more alloying elements, other than carbon, to enhance
properties
B. Higher carbon content
C. Lower hardness and strength
D. A simpler chemical composition without additional elements
The addition of one or more alloying elements, other than carbon, to enhance properties
Alloy steels are tailored for specific applications through the addition of various elements.
What is the defining feature of ferritic and martensitic stainless steels?
A. They have less than 12 percent chromium content
B. They are characterized by a BCC crystal structure and good corrosion resistance
due to chromium
C. They possess an FCC crystal structure, which allows for easy hardening by
quenching
D. They have low resistance to corrosion
They are characterized by a BCC crystal structure and good corrosion resistance due to chromium
Ferritic and martensitic stainless steels have unique properties that make them suitable for different environments.
What is a key characteristic of austenitic stainless steels?
A. They cannot be hardened by heat treatment due to the absence of nickel
B. They possess an FCC structure and offer an excellent combination of strength,
ductility, and corrosion resistance
C. They are hardened by quenching due to their BCC crystal structure
D. They have high carbon content
They possess an FCC structure and offer an excellent combination of strength, ductility, and corrosion resistance
Austenitic stainless steels are widely used in various industries due to their favorable properties.
What is the function of precipitation-hardenable stainless steels?
A. They retain their properties only in the annealed condition
B. They are strengthened through precipitation reactions within the metal matrix,
often with elements like aluminum, titanium, copper, and nitrogen
C. They are easy to form but cannot be hardened
D. They rely on carbon content for their strength
They are strengthened through precipitation reactions within the metal matrix, often with elements like aluminum, titanium, copper, and nitrogen
This type of steel is engineered for high strength and specific performance characteristics.
What is the primary purpose of full annealing in steel heat treatment?
A. To increase hardness and strength
B. To improve machinability and reduce internal stresses
C. To soften the steel and increase ductility
D. To form a martensitic structure
To improve machinability and reduce internal stresses
Full annealing is a crucial process for enhancing the workability of steel.
Which heat treatment process is used to soften steel and improve its machinability by creating spheroidal iron carbide?
A. Normalizing C. Spheroidizing annealing
B. Process annealing D. Hardening (quenching)
Spheroidizing annealing
This process helps to achieve a desirable microstructure for machining applications.
What is the main concern when annealing austenitic stainless steels at temperatures between 850 and 1500°F?
A. The formation of martensite
B. The formation of carbides at grain boundaries, leading to sensitization and
intergranular corrosion
C. The increase of ductility and toughness
D. The reduction in hardness and strength
The formation of carbides at grain boundaries, leading to sensitization and intergranular corrosion
Sensitization can significantly affect the performance of stainless steels in service.
How does process annealing differ from full annealing?
A. It is done at a higher temperature
B. It is used to reduce ductility and improve hardness
C. It is performed below the lower critical temperature to improve ductility and
relieve stresses
D. It is used to increase the strength and hardness of the steel
It is performed below the lower critical temperature to improve ductility and relieve stresses
Process annealing is a critical step in the fabrication of steel products.
What happens to ferritic and martensitic stainless steels when slowly cooled from annealing temperatures?
A. They become more ductile and corrosion-resistant
B. They embrittle when held in the temperature range of 750 to 950°F
C. They become more heat-resistant and form a stronger microstructure
D. They exhibit an increase in hardness and strength
They embrittle when held in the temperature range of 750 to 950°F
This embrittlement can lead to failures in applications if not managed properly.
What is the main difference between normalizing and annealing in steel heat treatment?
A. Normalizing uses a slower cooling rate than annealing
B. Normalizing cools the steel in air, while annealing cools it in the furnace
C. Normalizing results in softer steel with lower tensile strength than annealing
D. Annealing produces harder steel than normalizing
Normalizing cools the steel in air, while annealing cools it in the furnace
Normalizing typically results in a finer grain structure compared to annealing.
What happens to steel during the hardening (quenching) process?
A. The steel transforms into pearlite, which improves ductility
B. The steel transforms into martensite, which increases hardness and abrasion
resistance
C. The steel becomes softer and more machinable
D. The steel retains its original microstructure
The steel transforms into martensite, which increases hardness and abrasion resistance
The transformation to martensite is crucial for achieving high hardness in steel.
What is a potential problem associated with tempering steel at certain temperatures?
A. The steel may become too soft for industrial applications
B. The steel may become brittle and prone to cracking
C. The steel may be prone to excessive oxidation
D. The steel may retain excessive internal stresses
The steel may become brittle and prone to cracking
Tempering is a delicate balance between reducing hardness and maintaining toughness.
Which of the following is true about martensitic steels?
A. They are very tough and easy to machine
B. They have high impact strength and low hardness
C. They are the hardest form of heat-treated steel with high strength and resistance
to abrasion
D. They are easily quenched and require no further heat treatments
They are the hardest form of heat-treated steel with high strength and resistance to abrasion
Martensitic steels are used in applications requiring high wear resistance.
What does the term ‘aging’ refer to in the context of material degradation in steels?
A. A heat treatment process that increases material strength
B. The slow metallurgical reaction that occurs when materials are exposed to
elevated temperatures for extended periods
C. The intentional use of aging to improve material properties
D. A process where materials degrade due to rapid cooling
The slow metallurgical reaction that occurs when materials are exposed to elevated temperatures for extended periods
Aging can lead to significant changes in mechanical properties over time.
Which of the following materials is most likely to experience aging due to prolonged exposure to elevated temperatures?
A. Ferritic steels above 900°F (482°C)
B. Martensitic steels at room temperature
C. Low-carbon steels at low temperatures
D. Austenitic stainless steels at or above 1000°F (538°C)
Austenitic stainless steels at or above 1000°F (538°C)
These steels are particularly sensitive to aging effects.
What is the main effect of aging on ferritic and austenitic steels?
A. Increased ultimate tensile strength
B. Increased ductility
C. Decreased yield strength after long exposure times
D. Enhanced resistance to corrosion
Decreased yield strength after long exposure times
The reduction in yield strength can impact the performance of components in service.
In the ASME Boiler and Pressure Vessel Code, which factor is used to determine the allowable design stress for a material exposed to elevated temperatures?
A. 100 percent of the material’s tensile strength
B. 2/3 of the specified minimum yield strength at room temperature
C. 80 percent of the minimum stress to cause rupture in 10,000 hours
D. 67 percent of the average stress to cause rupture in 100 hours
2/3 of the specified minimum yield strength at room temperature
This guideline ensures safety under varying temperature conditions.
How does the reduction in yield strength due to aging affect fatigue in materials?
A. It makes the material more resilient to operational transients
B. It increases the number of cycles before failure occurs
C. It causes more plastic strain from a given stress, leading to earlier failure
D. It has no significant effect on the material’s fatigue resistance
It causes more plastic strain from a given stress, leading to earlier failure
Aging can significantly impact the fatigue life of materials.
What property is most significantly affected by temper embrittlement in carbon and alloy steels?
A. Hardness C. Ductility
B. Toughness D. Corrosion resistance
Toughness
Loss of toughness can lead to brittle failures in structural applications.
Which elements are primarily responsible for making steel susceptible to temper embrittlement?
A. Chromium, molybdenum, and aluminum
B. Antimony (Sb), phosphorus (P), tin (Sn), and arsenic (As)
C. Silicon, manganese, and copper
D. Nickel, zinc, and magnesium
Antimony (Sb), phosphorus (P), tin (Sn), and arsenic (As)
These elements can adversely affect the performance of steels during service.
Which of the following factors is part of the embrittlement factor (X) formula developed by Bruscato?
A. The percentage of chromium in the steel
B. The concentration of antimony (Sb), phosphorus (P), tin (Sn), and arsenic (As)
C. The heat treatment temperature
D. The grain size of the material
The concentration of antimony (Sb), phosphorus (P), tin (Sn), and arsenic (As)
The formula helps predict susceptibility to embrittlement in various steels.
How does increasing the austenitizing temperature affect a steel’s susceptibility to temper embrittlement?
A. It decreases susceptibility to temper embrittlement
B. It increases susceptibility to temper embrittlement
C. It has no effect on susceptibility to temper embrittlement
D. It makes the steel more ductile
It increases susceptibility to temper embrittlement
Higher austenitizing temperatures can exacerbate embrittlement issues.
What effect does austenitizing temperature have on a steel’s susceptibility to temper embrittlement?
A. It decreases susceptibility to temper embrittlement
B. It increases susceptibility to temper embrittlement
C. It has no effect on susceptibility to temper embrittlement
D. It makes the steel more ductile
It increases susceptibility to temper embrittlement
This refers to the relationship between heat treatment and embrittlement in steels.
What is the effect of tempering the steel before the embrittling treatment?
A. It increases susceptibility to temper embrittlement
B. It makes the material stronger but less ductile
C. It decreases the degree of embrittlement and improves toughness
D. It has no effect on the material’s susceptibility to embrittlement
It decreases the degree of embrittlement and improves toughness
Tempering is a heat treatment process that enhances toughness.
What is the main cause of hydrogen attack in carbon and low-alloy steels?
A. Hydrogen atoms reacting with carbon to form methane
B. Excessive heat treatment during welding
C. High residual stresses in the material
D. The presence of high levels of chromium and molybdenum
Hydrogen atoms reacting with carbon to form methane
This reaction weakens the steel structure.
Why are weld regions more susceptible to hydrogen attack?
A. They have lower carbon content compared to the base material
B. They possess less stable carbides
C. They are resistant to high temperatures
D. They are enriched with chromium and molybdenum
They possess less stable carbides
The instability of carbides in weld regions contributes to hydrogen attack.
Which element is known to improve hydrogen-attack resistance in steels?
A. Nickel C. Chromium
B. Copper D. Silicon
Chromium
Chromium is added to enhance the resistance of steels to hydrogen attack.
What temperature range is associated with ‘885°F’ (474°C) embrittlement in ferritic stainless steels?
A. 320 to 538°F (160 to 280°C) C. 1020 to 1500°F (550 to 815°C)
B. 610 to 1000°F (320 to 538°C) D. 400 to 600°F (204 to 316°C)
610 to 1000°F (320 to 538°C)
This range highlights the critical temperatures for embrittlement.
Why are austenitic stainless steels essentially immune to hydrogen attack?
A. They have a low carbon content
B. Their FCC lattice accommodates hydrogen atoms without damage
C. They are free from chromium and molybdenum
D. They have a higher hardness, which prevents hydrogen infiltration
Their FCC lattice accommodates hydrogen atoms without damage
The face-centered cubic (FCC) structure is significant for hydrogen accommodation.
What is the result of graphitization in steels?
A. Increased mechanical strength at room temperature
B. Formation of graphite nodules, weakening the material
C. Improved creep rupture strength at elevated temperatures
D. Elimination of weld heat-affected zone weaknesses
Formation of graphite nodules, weakening the material
Graphitization typically leads to a decrease in mechanical strength.
Which type of steel is most susceptible to graphitization?
A. High-carbon steel
B. Carbon steel and carbon-molybdenum grades
C. Stainless steel
D. Alloy steels with high chromium content
Carbon steel and carbon-molybdenum grades
These steels are particularly prone to graphitization under certain conditions.
What is the effect of adding chromium to steel in terms of graphitization?
A. It increases susceptibility to graphitization
B. It completely prevents graphitization
C. It accelerates the graphitization process
D. It reduces creep strength
It accelerates the graphitization process
Chromium can enhance the susceptibility of steels to graphitization.
At what temperature range are carbon and carbon-molybdenum steels susceptible to graphitization according to ASME Code?
A. 300°F to 400°F C. 800°F to 875°F
B. 400°F to 500°F D. 1000°F to 1200°F
800°F to 875°F
This range is critical for understanding graphitization risks.
Which material is recommended for high-temperature applications to prevent graphitization?
A. Carbon steel
B. Carbon-molybdenum steel
C. Chromium-containing steel grades like P22 and P91
Chromium-containing steel grades like P22 and P91
These grades are specifically designed to withstand high temperatures and resist graphitization.
What causes intergranular attack (IGA) in unstabilized austenitic stainless steels?
A. Rapid cooling from annealing
B. Formation of chromium carbides at grain boundaries
C. High tensile stresses in the material
D. Excessive exposure to oxidizing media
Formation of chromium carbides at grain boundaries
This process can significantly compromise corrosion resistance.
What is the result of sensitization in austenitic stainless steels?
A. Enhanced corrosion resistance
B. Formation of sigma phase
C. Increased susceptibility to intergranular attack
D. Improved toughness
Increased susceptibility to intergranular attack
Sensitization occurs when chromium carbides form at grain boundaries.
Which area of piping components is most often affected by intergranular attack (IGA)?
A. Weld regions
B. Surface coating
C. Low-temperature zones
D. Heat-affected zones away from the weld
Weld regions
Weld regions are particularly vulnerable to IGA due to thermal effects.
What is the primary consequence of sigma phase formation in high-alloy Fe-Cr and Fe-Ni-Cr alloys?
A. Increased corrosion resistance
B. Increased toughness at high temperatures
C. Reduced toughness at room temperature
D. Improved fatigue resistance
Reduced toughness at room temperature
Sigma phase can lead to embrittlement in certain alloys.
How can the formation of sigma phase be reversed in materials exposed to prolonged temperatures?
A. Cooling rapidly from the heat treatment
B. Exposing the material to an acidic environment
C. Subjecting the material to an annealing heat treatment
D. Increasing the alloy content
Subjecting the material to an annealing heat treatment
Annealing can help restore toughness by dissolving sigma phase.
What is the primary indication of severe creep damage in components operating at high temperatures and high stress?
A. Elongation or swelling of the component
B. Visible cracks on the surface
C. Increase in mechanical strength
Elongation or swelling of the component
This is a typical sign of damage due to prolonged high-temperature exposure.
Which method is commonly used for assessing microstructural damage in creep-damaged components?
A. Visual inspection with the naked eye
B. Destructive sampling and metallographic procedures
C. Liquid penetrant examination
D. Radiographic inspection
Destructive sampling and metallographic procedures
These methods provide detailed insights into microstructural changes.
In which component of the power piping industry has metallographic examination been most extensively applied?
A. Superheater piping C. Condenser tubes
B. Steam turbines D. Pressure relief valves
Superheater piping
Superheater piping is critical for ensuring performance under high temperatures.
What is the disadvantage of using the replication method for evaluating creep damage?
A. It can only examine the surface, leaving subsurface damage undetected
B. It is more costly than other methods
C. It requires destructive sampling
D. It can cause severe metallurgical alterations
It can only examine the surface, leaving subsurface damage undetected
This limitation can lead to an incomplete assessment of material integrity.
How is the expected rate of creep crack growth typically estimated?
A. Through direct observation of cracks over time
B. By analyzing baseline creep data of a given alloy
C. By using ultrasonic testing
D. Through visual inspection of surface features
By analyzing baseline creep data of a given alloy
Baseline data provides a reference for predicting creep behavior.
What is the main purpose of measuring oxide thickness in high-temperature tubing and piping components?
A. To estimate the remaining creep life of the component
B. To determine the tube’s oxidation rate
C. To calculate the hoop stress
D. To evaluate the alloy’s tensile strength
To estimate the remaining creep life of the component
Oxide thickness can indicate degradation due to high-temperature exposure.
Which tools are necessary for estimating remaining creep life using the oxide measurement technique?
A. Fatigue strength data for the alloy
B. Steam oxidation data and uniaxial creep-rupture data
C. Stress-corrosion data
D. Impact resistance data
Steam oxidation data and uniaxial creep-rupture data
These data sets are critical for accurate predictions.
What does the effective temperature represent in the context of oxide measurement?
A. The average temperature over the service life of the component
B. The temperature that would have resulted in the measured oxide thickness after
the known service time
C. The temperature at which the alloy reaches its maximum strength
D. The temperature at which the component experiences the highest stress
The temperature that would have resulted in the measured oxide thickness after the known service time
This helps correlate oxide growth with service conditions.
What does the Larsen-Miller Parameter (LMP) represent?
A. The temperature-dependent behavior of the alloy at various stress levels
B. A factor representing the actual condition of the operating component
C. The stress distribution in the tube or pipe over time
D. The oxide scale thickness at a given temperature
A factor representing the actual condition of the operating component
LMP is useful for assessing material performance over time.
Which industry has found the method for estimating remaining creep life most useful?
A. Aerospace C. Automotive
B. Fossil power boiler industry D. Chemical processing
Fossil power boiler industry
This industry relies heavily on maintaining component integrity under high stress.
What do the first two digits of the AISI/SAE four-digit number represent in carbon and low-alloy steels?
A. The grade of steel
B. The major alloying elements of the steel
C. The carbon content of the steel
D. The tensile strength of the steel
The major alloying elements of the steel
This classification aids in identifying steel compositions.
In the AISI/SAE system, what do the final two digits of a four-digit number represent for carbon and low-alloy steels?
A. The grade of steel
B. The nominal carbon content of the alloy
C. The percentage of alloying elements
D. The tensile strength of the alloy
The nominal carbon content of the alloy
This helps in specifying the carbon levels in the steel.
Which identification corresponds to chromium-nickel austenitic stainless steels in the AISI/SAE numbering system?
A. 2XX C. 4XX
B. 3XX D. 5XX
3XX
This classification is essential for identifying stainless steel types.
Which organizations have generated comprehensive material specifications for properties, heat treatment, and inspections?
A. AISI and SAE C. UNS and ASTM
B. ASTM, ASME, and API D. AISI, SAE, and UNS
ASTM, ASME, and API
These organizations set standards for material quality and performance.
What is the primary limitation for the use of copper and copper alloys?
A. They can only be used in low-pressure systems.
B. They are limited to temperatures below the lower recrystallization temperature of
the alloy.
They are limited to temperatures below the lower recrystallization temperature of the alloy
This restriction affects the applications of copper alloys.
Which brass alloy can be used successfully at temperatures up to 400°F (200°C)?
A. Brass containing 60 percent copper
B. Brass containing 70 percent or more copper
C. Brass containing 80 percent copper
D. Brass containing 90 percent copper
Brass containing 70 percent or more copper
This composition is suitable for higher temperature applications.
Which material is known for its resistance to oxidation and corrosion in turbine blading and power plant accessories?
A. Brass C. Nickel and Monel alloys
B. Aluminum D. Copper alloys
Nickel and Monel alloys
These materials are preferred for their durability in harsh environments.
What effect does alloying aluminum with Cu, Mg, and Si have on its properties?
A. It increases thermal and electrical conductivity
B. It makes the material age-hardenable and heat-treatable
C. It increases its susceptibility to galvanic attack
D. It lowers the material’s melting point without affecting strength
It makes the material age-hardenable and heat-treatable
These alloying elements enhance the performance characteristics of aluminum.
What is the purpose of tempering in steel heat treatment?
A. To increase the hardness and strength
of the steel
C. To create a martensitic structure
B. To reduce the brittleness of the steel
and increase its toughness
D. To remove all alloying elements from
the steel
To reduce the brittleness of the steel and increase its toughness
Tempering is crucial for improving the mechanical properties of steel.
What is the primary function of chromium when added to steel?
A. Increases corrosion resistance at room
temperature
C. Increases ductility and toughness at
low temperatures
B. Acts as a hardening element and
improves strength at higher
temperatures
D. Reduces the tensile strength of steel
Acts as a hardening element and improves strength at higher temperatures
Chromium is a key alloying element that enhances steel performance.
What is the purpose of tempering in steel heat treatment?
A. To increase the hardness and strength
of the steel
C. To create a martensitic structure
B. To reduce the brittleness of the steel
and increase its toughness
D. To remove all alloying elements from
the steel
To reduce the brittleness of the steel
What is the purpose of tempering in steel heat treatment?
A. To increase the hardness and strength
of the steel
C. To create a martensitic structure
B. To reduce the brittleness of the steel
and increase its toughness
D. To remove all alloying elements from
the steel
To reduce the brittleness of the steel
What is the primary function of chromium when added to steel?
A. Increases corrosion resistance at room
temperature
C. Increases ductility and toughness at
low temperatures
B. Acts as a hardening element and
improves strength at higher
temperatures
D. Reduces the tensile strength of steel
Acts as a hardening element and
improves strength at higher
temperatures
What is the primary function of chromium when added to steel?
A. Increases corrosion resistance at room
temperature
C. Increases ductility and toughness at
low temperatures
B. Acts as a hardening element and
improves strength at higher
temperatures
D. Reduces the tensile strength of steel
Acts as a hardening element and
improves strength at higher
temperatures
