1. Heat treatment of ferrous metals

Question 1

Name some forms of heat treatment that can be applied to ferrous metals

Answer 1

1. annealing
2. normalising
3. hardening and tempering

Question 2

What is annealing?

Answer 2

is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and to make it more workable. It involves heating a material to above its glass transition temperature, maintaining a suitable temperature, and then cooling. Annealing can induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.

Question 3

In ferrous metals how are they cooled after annealing?

Answer 3

such as steel, which must be cooled slowly to anneal. In this fashion, the metal is softened and prepared for further work—such as shaping, stamping, or forming.

Question 4

What are the two basic types of annealing?

Answer 4

1. Process annnealing- heating to 550-650 degreees to relieve any stress from distorted grains caused by cold working or deformation.
2. Full annealing- heating into the austenite region and cooled very slowly (furnance) which gives a softer, coarser grained steel in the unstressed state.

Question 5

What is normaliing?

Answer 5

Normalising involves heating a steel up into the austentie region well above the UTC. When the structure is all austentie, iti is then cooled in still air. The process takes less time than full annealing and produces a finer grained structure and hence a stronger steel.

Cast-steel is often normalized rather than annealed, to decrease the amount of distortion that can occur. Tempering is often needed to reduce the hardness and increase the toughness of the steel.

Question 6

What is Hardening