Application of steels

Question 1

What are low-carbon steels?

Answer 1

Steels that contain less than 0.3% C.

Question 2

What are some mechanical properties of low-carbon steels (structural steels) and their applications?

Answer 2

Mechanical properties: soft, weak, ductile, and tough.
Applications: automobile body components, structural shapes, pipelines.

Question 3

How can low-carbon steels (structural steels) be strengthed?

Answer 3

Because low-carbon steels are soft and weak a good strengthening mechanism would be normalization as tempering is used mainly for very hard materials.

Question 4

What are medium-carbon steels (machine steels)?

Answer 4

Steels that contain between 0.3-0.6% carbon content.

Question 5

What are some mechanical properties of medium-carbon steels (machine steels) and their applications?

Answer 5

Mechanical properties: moderate ductility and machinability, higher hardness and strength than low-carbon steels.
Application: railway wheels, crankshafts.

Question 6

How to improve the mechanical properties of medium-carbon alloys (machine steels)?

Answer 6

Quenching and tempering to achieve higher hardness and strength levels.

Question 7

What are high-carbon steels (tool steel)?

Answer 7

Steel with carbon concentration between 0.6-1.5%.

Question 8

What are some mechanical properties of high-carbon steels (tool steel) and their applications?

Answer 8

Mechanical properties: hard, wear-resistant, and brittle, least ductile.
Applications: cutting tools, knives, dies etc.

Question 9

What is a surface treatment machine steels and tool steels require?

Answer 9

Carburizing and nitriding to form harder outer shells while maintaining a ductile core.