Question 1

Foundry practice: purpose of the cupola furnace  A cupola is employed in foundries primarily to produce or melt which ferrous material for casting? Choose the correct option.

Accepted Answer

Concept The cupola furnace is a vertical shaft furnace used in foundries to melt cast iron (by remelting pig iron and scrap with coke and flux). Final Answer Cast iron

Question 2

Where is cast iron manufactured/melted for foundry use?  Select the most appropriate furnace commonly used to produce molten cast iron from pig iron and scrap for casting. Choose the correct option.

Accepted Answer

Concept Pig iron is produced in a blast furnace. For foundry casting, pig iron (with scrap and fluxes) is remelted in a cupola to produce molten cast iron. Open hearth and Bessemer are steelmaking processes. Final Answer Cupola

Question 3

Work-hardenable alloy steel for earthmoving equipment blades  Blades of bulldozers, bucket wheel excavators, and similar equipment use a work-hardenable alloy steel. Besides Fe and C, which alloying element characterizes this steel? Choose the corre…

Accepted Answer

Concept The steel is Hadfield manganese steel (~12–14% Mn), famous for extreme work hardening and high impact resistance, widely used for shovel/bulldozer blades, crusher liners, and track components. Final Answer Manganese

Question 4

Superalloys: nickel content comparison between Nimonic and Inconel  Complete the statement about Ni content: “Nimonic contains __________ percentage of nickel as compared to Inconel.” Choose the best completion.

Accepted Answer

Concept Nimonic grades are typically very high in Ni (often ~70–80% for classic grades like Nimonic 75), whereas common Inconel grades span ~50–72% Ni depending on type (e.g., 718 ~ 50–55%, 625 ~ ~60%, 600 ~ ~72%). Hence, in general wording, Nimonic contains a higher percentage of nickel than Inconel. Final Answer A higher

Question 5

Electric steelmaking: suitability for specialty steels  Electric furnace steelmaking is especially adopted for which categories of steels? Choose the correct option.

Accepted Answer

Concept Electric arc and induction furnaces provide precise composition control, low contamination, and high temperatures suited to high-grade alloy steels, including tool steels, magnet steels, and high-speed steels. Final Answer All of these

Question 6

Bessemer converter operation: interpreting the white flame  Statement to evaluate: “The dying down of the white flame during Bessemer blowing indicates that the air is burning out silicon and manganese.” Decide whether the statement is correct or in…

Accepted Answer

Concept In the Bessemer process, Si and Mn oxidize first, and then C is oxidized vigorously, producing the characteristic bright/white flame. The flame dying down signals that carbon has been largely removed, not that Si and Mn are being burned out (that occurs earlier). Final Answer Incorrect (False)

Question 7

General property of cast iron (as a class of ferrous alloys)  Cast iron, in general (ignoring special ductile/malleable grades), is best described as which type of material? Choose the correct option.

Accepted Answer

Concept Typical gray and white cast irons contain flake or combined carbon morphologies that make them brittle under tensile loading (low ductility). Special grades (malleable iron, ductile/nodular iron) are exceptions, but the general statement for “cast iron” is brittleness. Final Answer Brittle material

Question 8

Non-destructive testing (NDT): identify what type of flaws dye penetrant inspection can reveal  Given standard liquid penetrant testing conditions for metals and non-porous materials, determine the class of defects this method is best suited to dete…

Accepted Answer

Given Dye (liquid) penetrant method for defect detection. Concept/Approach Liquid penetrant testing relies on capillary action. A low-viscosity dye seeps into surface-breaking discontinuities and then bleeds out under developer to reveal indications. It cannot detect subsurface flaws because it requires an open-to-surface path. Elimination Core defects (a) are internal; not detectable unless they break the surface.Superficial (c) is vague and not an NDT category; meaningful targets are cracks, seams, laps, porosity that open to the surface.Temporary defects (d) is not an engineering category. Final Answer Surface defects (surface-breaking flaws)

Question 9

Metallurgical processing: choose the correct definition of smelting in iron extraction  Differentiate smelting from ore dressing (washing) and calcination/roasting by selecting the correct description used in ironmaking. Choose the correct option.

Accepted Answer

Given Select the statement that defines smelting. Concept Smelting = chemical reduction of metal oxides by carbon (or CO) at high temperature in the presence of a flux to form metal and slag.Ore washing (a) = physical beneficiation.Calcination/roasting (b) = thermal decomposition/oxidation to remove volatiles/impurities. Reasoning Only option (c) describes the reduction step of ironmaking. Therefore, (d) is incorrect because (a) and (b) are distinct, earlier steps. Final Answer Reducing the ore with carbon in the presence of a flux (smelting)

Question 10

Iron content in haematite (Fe₂O₃): select the closest percentage by mass  Haematite iron ore composition question for basic metallurgy and materials engineering. Choose the nearest iron percentage.

Accepted Answer

Given Haematite is Fe₂O₃. Step-by-Step calculation M(Fe₂O₃) ≈ 2 × 55.85 + 3 × 16.00 = 111.70 + 48.00 = 159.70 g/molMass of Fe in Fe₂O₃ = 111.70 g%Fe = (111.70 / 159.70) × 100 ≈ 69.9% ≈ 70% Concept Ideal haematite contains about 70% iron by mass; the rest is oxygen (ignoring gangue). Final Answer 70%

Question 11

Heat treatment: effects of normalising on steel properties  For plain carbon steels after normalising, identify the combined property changes relative to the annealed condition. Choose the correct set of effects.

Accepted Answer

Given Normalising heat treatment of steel. Concept Normalising refines grain size and produces a more uniform pearlitic/ferritic structure than annealing. This typically raises strength (UTS), raises yield point, and reduces ductility compared with the annealed state. Final Answer All of these

Question 12

Atomic arrangement classification: material with order in some directions only  Identify the correct term for a material whose atoms are regularly arranged in some directions but not in others (partially ordered structure). Choose the correct classi…

Accepted Answer

Concept Crystalline: long-range periodic order in three dimensions. Amorphous: no long-range order. Mesomorphous (mesophase): partial/anisotropic order (e.g., liquid crystals) — ordered in some directions, disordered in others. Reasoning The description matches a mesomorphic state (partial long-range orientation), not fully crystalline or fully amorphous. Final Answer Mesomorphous material (e.g., liquid crystalline)

Question 13

Steel at the eutectoid composition: identify the resulting room-temperature microstructure  Consider plain carbon steel of eutectoid composition cooled appropriately. Choose the correct phase constitution.

Accepted Answer

Concept Eutectoid composition (≈ 0.76–0.80% C) transforms at 723°C (A₁) to 100% pearlite (lamellae of ferrite + cementite). Elimination Below A₁ at room temperature, austenite (b) cannot persist in plain carbon steel.Hypoeutectoid steels contain ferrite + pearlite; hypereutectoid contain pearlite + cementite. Exactly eutectoid is 100% pearlite. Final Answer Wholly pearlite

Question 14

Cast irons: evaluate the statement about white cast iron's tensile and compressive strengths  White cast iron has a high tensile strength and a low compressive strength. Decide whether this statement is correct or incorrect and select the best optio…

Accepted Answer

Concept Cast irons, including white cast iron, characteristically have high compressive strength and low tensile strength. White cast iron has cementite networks that make it hard and brittle, leading to very poor tensile ductility and strength but good compressive capacity. Therefore The statement reverses the usual trend and is incorrect. Final Answer False

Question 15

Iron–carbon diagram: select the lower critical temperature (A₁) common to all steels  Identify the standard lower critical point for steels on heating/cooling (eutectoid temperature). Choose the correct temperature.

Accepted Answer

Concept The lower critical temperature A₁, i.e., eutectoid transformation temperature for plain carbon steels, is approximately 723°C. 913°C corresponds to A₃ for pure iron (α→γ transition), not the universal lower critical for steels.

Question 16

Iron ore occurrence: usual chemical form in nature  Considering common commercial iron ores, identify the chemical class in which iron is usually found. Choose the correct option.

Accepted Answer

Concept Commercial iron ores are predominantly oxides/hydroxides: haematite (Fe₂O₃), magnetite (Fe₃O₄), limonite/goethite (hydrated oxides). Carbonate (siderite, FeCO₃) exists but is less common as a primary commercial ore; sulphides (e.g., pyrite) are not typical iron ores due to sulphur problems. Final Answer Oxides

Question 17

Mechanical property definition: energy absorption in the plastic range  Identify the property of a material that measures its ability to absorb energy by plastic deformation before fracture. Choose the correct term.

Accepted Answer

Concept Toughness = area under the entire stress–strain curve up to fracture; energy absorbed in the plastic range (and elastic range). Resilience = energy absorbed within the elastic range only. Creep = time-dependent deformation under constant load. Fatigue strength = stress amplitude causing failure after many cycles. Final Answer Toughness

Question 18

Magnetic steels: alloying element that raises residual magnetism and coercive force  Identify the alloying element most effective for increasing both remanence (residual magnetism) and coercivity in steels used for permanent magnets. Choose the corr…

Accepted Answer

Given Selection of an alloying element for steel magnets that increases both residual magnetism (remanence) and coercive force. Concept / Approach Cobalt additions in magnetic steels (e.g., Alnico-type alloys) increase saturation magnetization, improve remanence, and raise coercivity, making the steel suitable for permanent magnets. Nickel typically improves permeability but not coercivity to the same extent; chromium and vanadium have other primary roles (hardenability, grain refinement, secondary hardening). Option analysis • Chromium: more for corrosion resistance/hardenability; not the best for coercivity + remanence together. • Nickel: improves toughness/permeability; not the strongest effect on coercivity. • Vanadium: strong carbide former; improves wear resistance and secondary hardening. • Cobalt: boosts remanence and coercivity. Final Answer Cobalt

Question 19

Crystal structure of γ-iron (austenite)  Identify the space lattice of gamma iron (the high-temperature phase of iron known as austenite). Choose the correct option.

Accepted Answer

Concept Gamma iron (austenite) has a face centred cubic (FCC) structure. Alpha iron (ferrite) is BCC at room temperature, while HCP does not occur in pure iron under normal conditions. Final Answer Face centred cubic (FCC) space lattice

Question 20

Microstructure and properties: ferrite + pearlite  Evaluate the statement about plain carbon steels: “Ferrite and pearlite make the steel soft and ductile.” Choose the correct option.

Accepted Answer

Concept In plain carbon steels, a matrix of ferrite (very soft, ductile) with pearlite (lamellar ferrite + cementite) yields an overall soft and ductile behavior (typical of low-carbon and mild steels). Increasing pearlite content raises strength but maintains useful ductility. Final Answer Correct (True)

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