1. Changing Properties Produced by Neil Liggett

2. Heat Treatments Heat Treatment is carried out to give a material the desirable properties, both mechanical and physical, to enable it to carry out its function when formed into engineering components. Image taken: http://www.jakejames.ca/classes.php

3. Heat Treatments. Hardening –  A material is hardened to be more resistant to wear & abrasion.  Heat treatment furnaces are used to induce the high temperatures.

4. Heat Treatments. Tempering –  To reduce brittleness in a hardened steel,  Relieve internal strains in material,  Colour schemes can be identified through the temperatures of the tempering process. View the link of tempering – www.technologystudent.com/images4/heatt4.gif

5. Heat Treatments. Annealing –  Exact opposite to hardening,  Relieves internal stresses,  Induces softness for machining, forming etc.

6. Heat Treatments. Steel changes its colour throughout heat treatment processes – Image Taken: http://members.optusnet.c om.au/terrybrown/HeatTe mperChartEtc.html

7. Heat Treatments. Normalising  This is similar to annealing, the main object being to relieve stresses set up by the previous heat treatment or cold working. Thus, restoring the metal to its normal condition. The procedure is the same as for annealing but the cooling rate should be slightly quicker preferably in still air.