Extraction of iron and steel Final Form  Molten steel to final form  Molten steel to Ingots to desired shape

Extraction of iron and steel Molten steel to direct final form  Coarsely Crystalline  Relatively brittle and weak

Extraction of iron and steel 1.Molten steel to Ingots 2.Ingots to desired shape Process Involved is rolling with heat treatment Improvement of properties Ductility Crystalline structure

Extraction of iron and steel Rolling

Extraction of iron and steel 1.Molten steel to Ingots 2.Ingots to desired shape Process Involved is forging Close small cavities Reduce the grain size Increase the density of the steel

Forging of steel Shaping the metal using compressive stresses

Extraction of iron and steel 1.Molten steel to Ingots 2.Ingots to desired shape Process Cold working : Any plastic deformation below the lowest critical temperature Introduction of Strain hardening Significant increase in tensile strength Significant decrease in ductility

Extraction of iron and steel Heat treatment for improvement of properties  Annealing  Hardening  Tempering

Annealing Process: 1.Heating at 800 o C 2.Maintaining heat at 800 o C 3.Gradual cooling Benefits 1.Production of softness 2.Relieving of internal strains 3.Refinement of the grain size 4.Weaker but ductile steel 5.Tougher

Annealing Process: 1.Heating at 800 o C 2.Maintaining heat at 800 o C 3.Rapid cooling Benefits 1.Normalized 2.Relieving of internal strains 3.Refinement of the grain size

Hardening Cooling by sudden immersion in quenching medium like 1.Oil 2.Water 3.Brine Due to quenching steel becomes brittle

Tempering Reheating at 200 to 500 o C Lower than preliminary heating Slow or rapid cooling Also know as drawing operation 1.Steel becomes softer 2.Steel becomes ductile 3.Tougher than all others