128 Questions
What is the primary focus of the first part of this chapter?
Mechanical properties of metals
What is the minimum percentage of iron required for an alloy to be classified as ferrous?
50%
Which of the following is NOT a mechanical property of metals?
Conductivity
What is the term for a material specimen used to measure and quantify a mechanical property?
Coupon
Which of the following is a thermodynamic property of materials?
Boiling point
What is the ultimate criterion for choosing metals in power engineering?
Serviceability and safety
Which type of material provides little warning that it is about to fail?
Brittle material
What is the property of a material that enables it to be drawn out to a considerable extent before breaking?
Ductility
Which of the following materials is NOT ductile?
Cast iron
What is the property of a material that allows it to return to its original shape after a deforming force has been removed?
Elasticity
What is the term used to describe a material that is very soft and easily deformed?
Plastic
Which of the following is an example of a material with high plasticity?
Wax
What is the property of a material that allows it to be hammered or rolled into other sizes and shapes?
Malleability
Which of the following is a type of strength that is described as the maximum load a material can withstand before breaking?
Ultimate Strength
What is the term used to describe a material's ability to resist deformation under load?
Strength
What is the purpose of the Izod and Charpy tests?
To determine the toughness of a material
What is the primary purpose of a coupon in material testing?
To represent a sample of the metal and apply forces to it
What is the term for a metal that is hard only on the surface?
Case hardening
What is the primary method of measuring hardness in the Brinell Hardness Test?
Measuring the diameter of the circular indentation
What is the standard load used for steel in the Brinell Hardness Test?
3000 kg
What is the purpose of the 10 kg load in the Rockwell Hardness Test?
To flatten surface irregularities
What is the name of the method that measures the hardness of a material by dropping a hard steel object from a measured height?
Shore Hardness method
What is brittleness?
The tendency of a material to break rather than remain deformed
What is the term for the ability of a material to resist wear, abrasion, cutting, and indentation?
Hardness
What is the purpose of the masses in the Brinell Hardness Test?
To act as a pressure relief system
What is the term for the ability of a material to change shape under load without breaking?
Ductility
What is the primary advantage of nickel in alloy steel?
Prevents brittleness at low temperatures
What is the minimum percentage of chromium required for a steel to be classified as stainless steel?
12.0%
What is the effect of vanadium on alloy steel?
Produces a fine grain structure
What is the primary benefit of molybdenum in alloy steel?
Improves creep strength
What is the advantage of chrome molybdenum steel in high-temperature steam piping?
High creep strength and resistance to oxidation
What is the effect of tungsten on alloy steel?
Produces a fine grain structure
What is the first material produced by the iron ore refining process?
Pig iron
What is the purpose of limestone in the blast furnace process?
To combine with impurities and form a slag
What is the characteristic of pig iron that makes it hard, brittle, and almost impossible to machine?
High carbon content
What is the difference between white cast iron and grey cast iron?
The way carbon is combined with the iron
What is the process that produces wrought iron?
Puddling
What is the primary characteristic of grey cast iron?
Low compressive strength and easy machinability
Why is pig iron not directly useful?
It is hard, brittle, and almost impossible to machine
What is the primary difference between cast iron and steel?
The amount of carbon they contain
What is the purpose of annealing in the production of malleable cast iron?
To increase the toughness and ductility of the material
What is the former use of wrought iron that has been replaced by steel?
Boiler tubes and piping
What is the primary function of limestone in the basic oxygen furnace?
To neutralize the acidic oxides and prevent wear of the furnace lining
What is the result of the excess carbon in the pig iron being burned in the BOF?
Production of carbon monoxide
What is the purpose of the oxygen lance in the BOF?
To oxidize the carbon and other unwanted elements in the hot metal
What is the characteristic of low carbon steels?
They are easily formed and welded
What is the effect of increasing the carbon content in high and very high carbon steels?
It increases the hardness and strength of the steel
What is the purpose of annealing high carbon steel?
To soften the steel to allow machining
What is the advantage of alloy steels over carbon steels?
They can respond to heat treatment and have improved corrosion resistance
What is the result of the chemical processes in the BOF?
Production of a slag that floats on the surface of the metal
What is the purpose of the slag produced in the BOF?
It is used in the production of cement and as an aggregate in road building
What is the difference between high carbon steel and very high carbon steel?
The carbon content ranges from 0.45% to 0.75% and from 0.75% to 1.5%, respectively
Which of the following properties is NOT classified as a thermodynamic property?
Conductivity
What is the primary consideration in selecting metals for power engineering applications?
Serviceability and safety
Which of the following metals is classified as non-ferrous?
Copper
What is the purpose of applying force to a material specimen in material testing?
To measure its mechanical properties
Which of the following is a characteristic of ferrous metals?
They contain at least 50% iron
What is the term for the material specimen used in material testing?
Coupon
What is the primary function of the hydraulic pump in the Brinell Hardness Test?
To apply the load to the test specimen
What is the significance of the 10 kg load in the Rockwell Hardness Test?
It is used to flatten surface irregularities
What is the characteristic of a material that is brittle?
It breaks rather than remains deformed
What is the purpose of the masses in the Brinell Hardness Test?
To act as a pressure relief system
What is the difference between the Brinell Hardness Test and the Rockwell Hardness Test?
The method of measuring the hardness
What is the significance of the hardness of a material in engineering design?
It determines the material's weldability
What is the purpose of using a diamond indenter in the hardness test?
To test the hardness of very hard materials
What is the relationship between the load and the hardness number in the Brinell Hardness Test?
The hardness number is directly proportional to the load
What is the significance of the Shore Hardness method in material testing?
It is used to test the hardness of plastics and non-ferrous metals
What is the primary difference between the Rockwell B and Rockwell C readings?
The size of the indenter
A material that is capable of being drawn out to a considerable extent before breaking exhibits which property?
Ductility
What is the primary characteristic of a material that is defined as brittle?
It provides little warning that it is about to fail
A material that is able to resist deformation under load exhibits which property?
Strength
What is the primary difference between the Izod and Charpy tests?
The way the specimen is supported
A material that is able to be hammered or rolled into other sizes and shapes exhibits which property?
Malleability
What is the term used to describe the ability of a material to change shape under load without breaking?
Plasticity
A material that is able to return to its original shape after a deforming force has been removed exhibits which property?
Elasticity
What is the term used to describe a material's ability to resist wear, abrasion, cutting, and indentation?
Hardness
Which of the following materials is an example of a ductile material?
Mild steel
What is the primary characteristic of a material that is defined as plastic?
It is very soft and easily deformed
Which of the following alloying elements in steel improves its corrosion resistance at high temperatures?
Nickel
Which of the following properties of steel is improved by the addition of chromium?
Corrosion resistance
What is the primary reason for heating alloy steels before, during, and after welding?
To avoid residual stresses
Which of the following alloying elements in steel produces a fine grain structure during heat treatment?
Vanadium
What is the primary benefit of using chrome molybdenum steel in high-temperature steam piping?
High creep strength
What is the primary purpose of the limestone in the blast furnace during the production of pig iron?
To remove impurities from the iron ore
What is the result of the carbon precipitating out of solution as flakes or nodules during the cooling of cast iron?
The formation of grey cast iron
Which of the following alloying elements in steel improves its machinability?
Lead
What is the term used to describe the process of heating and cooling white cast iron to increase its toughness and ductility?
Annealing
What is the primary difference between pig iron and cast iron?
Pig iron has a higher carbon content than cast iron
What is the purpose of the puddling process in the production of wrought iron?
To produce a plastic mass that can be formed into a ball
What is the characteristic of grey cast iron that makes it suitable for machinery bases and internal combustion engine components?
Its high compressive strength and softness
What is the primary difference between plain carbon steels and alloy steels?
The presence of additional elements in alloy steels
What is the result of the molten pig iron being tapped into ladles or cast into molds?
The production of pig iron that is ready for use
What is the primary characteristic of white cast iron that makes it suitable for machinery parts that are subjected to excessive wear?
Its high hardness and brittleness
What is the primary purpose of the cupola furnace in the production of cast iron?
To melt pig iron and scrap iron together
What is the primary reason why the furnace lining in the BOF is made of high pH refractory?
To prevent excessive wear of the furnace lining
What is the effect of increasing the carbon content in high and very high carbon steels?
The steel becomes more brittle and less weldable
What is the purpose of the fluxing agent in the BOF?
To remove impurities from the steel
What is the characteristic of alloy steels that allows them to respond to heat treatment?
Their ability to form compounds with carbon
What is the result of the chemical processes in the BOF?
A slag that floats on the surface of the metal
What is the primary advantage of producing special high alloy steels in electric furnaces?
The ability to produce steel with a more uniform composition
What is the effect of phosphorus and sulfur impurities on the properties of steel?
They decrease the ductility, malleability, and weldability of the steel
What is the purpose of the oxygen lance in the BOF?
To oxidize the carbon and other unwanted elements in the hot metal
What is the primary difference between high carbon steels and very high carbon steels?
Their carbon content
What is the purpose of the slag produced in the BOF?
To be used in the production of cement and as an aggregate in road building
What is the primary advantage of using aluminum in aircraft parts?
Low density
What is the primary purpose of adding phosphorus to bronze?
To produce bearing bronzes
What is the primary characteristic of white metal (babbitt) that makes it suitable for bearing materials?
Malleability and ductility
What is the primary difference between tin-based and lead-based babbitts?
Speed and load capacity
What is the primary advantage of lead-based babbitt over tin-based babbitt?
Lower cost
What is the primary reason why aluminum is alloyed with other materials?
To improve its properties in general
What is the primary reason copper is used in power plants?
Due to its high electrical conductivity and high corrosion resistance
What is the result of mixing molten copper with other metals?
A stronger and more corrosion-resistant material
What is the primary component of brass, besides copper?
Zinc
What is the purpose of using copper alloys in power plants?
For heat exchanger tubes, valves, and fittings due to its superior properties
What is the significance of copper's high ductility in power plant applications?
It allows copper to be drawn out to a considerable extent without breaking
What is the advantage of using copper alloys over pure copper in power plants?
They are easier to machine and have better corrosion resistance
What is the primary reason that copper alloys are used instead of pure copper in power plants?
easier to machine
What is the typical composition of brass alloys?
copper and zinc
What is the primary application of copper in power plants?
electrical equipment and piping
What is the process by which copper is refined from copper ore?
electrolysis
What is the property of copper that makes it suitable for use in electrical equipment?
high electrical conductivity
What is the result of mixing molten copper with other metals?
a alloy with superior properties to pure copper
What is the primary reason for adding zinc to bronze alloys?
To ensure non-porous castings and improve machining qualities
Which of the following properties of aluminum is responsible for its use in aircraft parts?
Its low density
What is the primary advantage of using tin-based babbitt over lead-based babbitt?
Its better performance at higher speeds and higher loads
What is the primary reason for alloying aluminum with other materials?
To improve its tensile strength
What is the primary characteristic of white metal (babbitt) that makes it suitable for bearing materials?
Its ability to absorb and retain a lubricant film on the surface
Which of the following is a characteristic of bronze alloys?
High resistance to corrosion and high tensile strength
Test your understanding of material properties, including chemical and physical properties, such as thermodynamic, electrical, and mechanical properties. Learn how to classify and identify different properties of materials. Evaluate your knowledge of material properties and their importance in engineering applications.
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