Object

To compare the tensile strengths, moduli of elasticity of cast irons and investigate their microstructure.

Method: Part One

 Measure the dimensions of the specimens and calculate the cross-sectional area. Specimens will be tested on the Tinius Olsen and Lloyds tensometers, which will produce graphs of load/extension. Calculate the ultimate tensile strengths and moduli of elasticity of the grey cast iron and Spheroidal graphite (SG) cast iron.

Method: Part Two

 Several cast iron specimens will be available for microscopic examination. Sketch the structures, noting any phases present or observations. Label each drawing.

Health & Safety

Follow normal laboratory rules.

Discussion & Further Reading

1. Compare the strengths of the materials. Also observe the failure in terms of brittleness and ductility.
2. Describe the presence of carbon in cast irons and the problems associated with its different forms.
3. What are the different categories of irons and what are their applications in today’s industries?

Conclusion

Comment on the differences between steels and irons, review their comparisons and justify why irons are just as important as other engineering alloys.