Annealing Metals

Answer each question in your jotter then look at the next slide to check your answer.

• 1) What is Work Hardening?

When a metal is worked (hammered or rolled) the structure of the metal changes and work hardening occurs. Effectively the metal becomes harder to shape. Annealing reverses this process and makes the metal easier to work

Annealing is a heat treatment of a metal designed to produce a soft, ductile condition. Typically the metal is heated and allowed to cool slowly.

Work HardeningBossing Mallet

Sand Bag

The Forge

• 2) When using the forge what safety precautions should you take?

Annealing Metals

When annealing metals the following safety equipment should be worn.

Leather Apron

Goggles

Leather Gloves

The Forge

Hearth

Canopy

Fire Bricks

On / Off Switch

Isolating Switch

Ceramic ChipsSpark Ignition

switch

Brazing Torch

Spark

Blacksmiths Tongs

1. Care should be taken when carrying hot metals (particularly metals at black heat that may not appear hot)

2. Clay bricks should not be heated as they can disintegrate violently.

3. Ceramic chips remain hot for a considerable time after the heat source has been removed.

4. Foreign materials present in the forge can cause fumes. Stones can explode.

5. Quenching of hot materials, particularly tubular components can cause risk of scalding.

6. Fuel combustion can produce dangerous gasses.

Pupils should be aware of the following hazards

Conditions of use.Appropriate safety equipment must be worn: Goggles, Leather gloves. (Leather apron where appropriate)

The Forge

• 3) How do you anneal Aluminium?

Due to aluminium's low melting temperature aluminium tends to melt before it turns red hot.

Annealing Aluminium

To overcome this when annealing aluminium you must follow this process(As you work the metal this process may need repeated a number of times)

1) Mark Aluminium with soap

2) Heat Aluminium until soap turns black

3) Quench

• 4) How do you anneal Copper?

Annealing Copper

To Anneal copper the metal is heated to a cherry red colour then quenched

(As you work the metal this process may need repeated a number of times)

Blacksmiths Tongs

• 5) How do you anneal Steel?

Annealing Steel

To Anneal Steel the metal is heated to a cherry red colour then allowed to cool slowly

(As you work the metal this process may need repeated a number of times)

The End