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To get a grade D: you will state the properties of iron and steel and give some simple uses To get a grade C: you should explain the properties of iron and steel and give advantages for steel over iron To get a grade B: you should give some uses of low-alloy and high-alloy steel as well as stainless steels and relate their properties to their uses To get a grade A/A*: you should give a process for turning iron into steel uses carbon atoms as an example

MAKING IRON Iron is made by the reduction of iron ore (Haematite) Fe 2 O 3. The equation is IRON OXIDE + CARBON MONOXIDE = IRON + CARBON DIOXIDE Iron is made in a blast furnace. Iron ore, coke (carbon) and limestone are fed in at the top, and hot air is blasted in to ignite the mixture.

Cast iron straight from the blast furnace is very hard and brittle. It is used for engine blocks, man-hole covers, cooking pans etc. It contains about 4% carbon which makes it brittle, IRON AND STEEL

Wrought iron is iron that has had all the carbon taken out of it. It is quite soft and malleable, and suitable for ornamental purposes WROUGHT IRON

STEEL Steel contains a small amout (around 1%) carbon. This makes it tough and suitable for many purposes

Iron Pure iron is soft and easily shaped. This is because its atoms are arranged in a regular way that lets layers of atoms slide over each other. Pure iron is too soft for many uses.

Alloys The properties of a metal are changed by including other elements, such as carbon. A mixture of two or more elements, where at least one element is a metal, is called an alloy. Alloys contain atoms of different sizes, which distort the regular arrangements of atoms. This makes it more difficult for the layers to slide over each other, so alloys are harder than the pure metal. It is more difficult for layers of atoms to slide over each other in alloys

iron + small amounts of carbon (0.03% - 1.5%) Cheapest type of steel Used for: car bodies, knives, ships, containers, machinery

High amount of carbon – very strong and brittle so likely to shatter Low amount of carbon – very soft and easily shaped so less likely to shatter

More expensive because they contain nickel, chromium, manganese, vanadium, titanium and tungsten… Long-span bridges… Bicycle chains… Military armour-plating… Very resistant to stretching forces…

REALLY expensive! This is because they contain lots of other metals. 12 – 15% chromium in chromium steels, as well as some nickel. So these are very strong and chemically stable. They don’t rust!

Complete the cut and stick activity for the different types of steel Type of steel Iron alloyed with: PropertiesTypical use low carbon steel about 0.25 per cent carbon easily shaped car body panels high carbon steel up to 2.5 per cent carbon hardcutting tools stainless steel chromium and nickel resistant to corrosion cutlery and sinks