fERROUS mETALS

Questions and Answers

Which type of strength measures a metal's ability to withstand stress in tension?

Compressive strength

Bending strength

Tensile strength (correct)

Shear strength

What is the maximum stress a material can withstand called?

Breaking strength

Yield strength

Ultimate strength (correct)

Fatigue strength

When the stress on a material leads to permanent deformation, what strength is being measured?

Yield strength (correct)

Breaking strength

Impact strength

Tensile strength

Which property describes a metal's ability to return to its original shape after deformation?

Elasticity Signup and view all the answers

What characteristic is defined by the metal's ability to resist fracture under sudden load?

Impact strength Signup and view all the answers

Which term is used to identify the stress coordinate on the stress-strain curve at rupture?

Breaking strength Signup and view all the answers

What effect does adding carbon to steel have on its properties?

Increases hardness Signup and view all the answers

Which of the following is NOT a type of metal strength?

Heat capacity Signup and view all the answers

What is the relationship between tensile strength and hardness in metals?

The tensile strength of steel relates directly to its hardness. Signup and view all the answers

Which property defines a metal's ability to resist repeated loading?

Fatigue strength Signup and view all the answers

Elasticity in metals is best described as the ability to:

Return to original shape after deformation. Signup and view all the answers

What is a characteristic of a brittle metal?

It tends to break or shatter under stress. Signup and view all the answers

How is fusibility defined in relation to metals?

The ability to be joined by heating and melting. Signup and view all the answers

Which of the following best describes conductivity in metals?

The ability to transmit heat or electricity. Signup and view all the answers

The region of a stress vs strain curve where a metal begins to deform plastically is known as:

Yield strength Signup and view all the answers

Which property is a good indicator of a metal's toughness?

The capability to absorb energy without breaking. Signup and view all the answers

Which statement regarding malleability and ductility is correct?

Malleability is the ability to be formed without cracking. Signup and view all the answers

Which of these properties is particularly important for aircraft structural materials?

Ductility and resistance to shock loads. Signup and view all the answers

How does annealing affect the properties of metals?

It enhances malleability by softening the metal. Signup and view all the answers

The coefficient of thermal expansion refers to:

The predictable amount of metal expansion with temperature changes. Signup and view all the answers

Ultimately, what distinguishes ferrous metals from non-ferrous metals?

The presence of iron as a chief constituent. Signup and view all the answers

In metalworking, what does work hardening refer to?

The development of internal stresses that make a metal harder. Signup and view all the answers

What is the primary purpose of heat treatment of steel?

To enhance physical and mechanical properties without changing shape Signup and view all the answers

Which element is most crucial in determining the mechanical properties of steel?

Carbon Signup and view all the answers

What effect does annealing have on steel?

Softens steel and relieves internal stress Signup and view all the answers

During the normalising process, what is the final cooling method for steel?

Cooling in air Signup and view all the answers

What is the consequence of quenching carbon steel too slowly?

Hardening of steel may not occur Signup and view all the answers

What does tempering primarily do to hardened steel?

Reduces brittleness and improves ductility Signup and view all the answers

Which process is best suited for creating hard, durable surfaces while maintaining toughness in the core of metal components?

Case hardening Signup and view all the answers

Which of the following is NOT a typical outcome of heat treatment processes for steel?

Transforming steel into pure iron Signup and view all the answers

In the context of heat treatment, which of the following statements about high-carbon steels is correct?

They are particularly suited for heat treatment processes. Signup and view all the answers

What is the role of quenching medium in the hardening process of carbon steel?

It controls the rate of temperature drop. Signup and view all the answers

What does the first digit in the SAE steel numbering system represent?

Principal alloying element Signup and view all the answers

How does increasing the carbon content in steel primarily affect its properties?

Makes it less ductile Signup and view all the answers

Which alloying element is primarily responsible for improving the machinability of steel when present in small amounts?

Sulphur Signup and view all the answers

What is the primary function of manganese in ferrous metals?

To reduce brittleness during forging Signup and view all the answers

Which pair of elements, when alloyed together, enhances both toughness and hardness in steel?

Nickel and Chromium Signup and view all the answers

Why is sulphur considered an undesirable impurity in steel?

It makes steel brittle when rolled or forged Signup and view all the answers

What characteristic does tungsten impart to steel when alloyed?

High melting point and density Signup and view all the answers

Which steel classification in the SAE system is primarily associated with high-carbon content?

1xxx Signup and view all the answers

Which alloying agent is most crucial for improving atmospheric corrosion resistance in low-carbon steel?

Phosphorous Signup and view all the answers

What does the last two digits of the SAE steel numbering system signify?

Average carbon content in hundredths of a percent Signup and view all the answers

Which statement best describes medium-carbon steels?

They can accept heat treatment and are adaptable for machining or forging. Signup and view all the answers

Which element, when alloyed with steel, serves to provide a hard surface finish in antifriction bearings?

Chromium Signup and view all the answers

How does adding titanium to steel generally affect its properties?

Enhances corrosion resistance and strength Signup and view all the answers

Why is molybdenum considered a significant alloying element in aircraft structural steel?

It reduces grain size and increases fatigue strength. Signup and view all the answers

Study Notes

Metal Properties and Characteristics

Metal characteristics include strength, hardness, malleability, ductility, brittleness, conductivity, elasticity, toughness, and density, crucial for manufacturing and construction decisions.
Alloying metals, such as adding carbon to steel, can significantly change their properties, enhancing strength and hardness.

Strength Classification

Metals exhibit various strengths, categorized as tensile, compressive, shear, torsional, bending, fatigue, and impact strength (toughness).
Tensile strength has three definitions: yield strength (elastic to plastic deformation point), ultimate strength (maximum stress before rupture), and breaking strength (stress at point of rupture).
Compressive strength resists being pressed, shear strength withstands shear stress, and torsional strength resists rotational shear.

Hardness and Malleability

Hardness measures a metal's resistance to cutting, penetration, or abrasion, significantly related to tensile strength, but varies across metals.
Malleability refers to the ability to shape metal without breaking; ductile metals can be formed into wires or rods, crucial for applications like aircraft components.

Ductility and Brittleness

Ductility allows a metal to be drawn into wire, important for structural integrity under shock loads, preferred in aerospace materials.
Brittleness is the tendency to shatter under stress, making materials like cast iron unsuitable for structural applications.

Elasticity and Toughness

Elasticity enables metals to return to their original shape after deformation; spring steel is a prime example.
Toughness is the ability to resist tearing and breaking, essential for tools like hammers and wrenches.

Conductivity and Thermal Expansion

Conductivity refers to a metal's capacity to carry heat or electricity; it is key for applications in wiring and thermal management.
Thermal expansion is the predictable change in metal volume with temperature variations, vital in engineering applications.

Fusibility

Fusibility enables metals to be joined together through melting, utilized in processes like welding.

Ferrous Metals Overview

Ferrous metals contain iron as their main component, including steel, cast iron, and titanium alloys; commonly used in aircraft structures.
Cast iron contains over 2% carbon and is known for high porosity, making it suitable for specific engine components but not as a structural material due to weight concerns.

Steel Composition and Identification

Steel is primarily iron with carbon; differences in carbon content produce variations like low, medium, and high-carbon steels.
The Society of Automotive Engineers (SAE) provides a four-digit numbering system to classify steel based on composition and carbon content.

Alloying Agents and Their Effects

Important alloying elements include carbon (increases hardness and strength), silicon (improves ductility), manganese (enhances wear resistance), and nickel (increases strength).
Chromium augments strength and corrosion resistance, while molybdenum enhances impact strength and is vital for aerospace applications.

Heat Treatment of Steel

Heat treatment processes alter steel properties without altering its shape, including annealing (softening), normalizing (stress relief), hardening (maximizing hardness), and tempering (reducing brittleness).
Case hardening is used for components requiring a tough core but hard surface, suitable primarily for low-carbon steels.

Special Alloying Elements

Vanadium strengthens steel when alloyed with chromium, while tungsten enhances wear resistance and retains hardness at high temperatures.
Titanium alloys are lightweight with exceptional tensile strength and corrosion resistance, suitable for extreme conditions.

Stainless Steel

Stainless steel is defined by its high chromium and nickel content, offering corrosion resistance and strength, making it ideal for high-temperature applications like exhaust systems.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the various properties and characteristics of metals, including strength, hardness, and malleability. This quiz covers different strength classifications, such as tensile and compressive strength, and the impact of alloying on metal properties. Test your understanding of these essential concepts in materials science.