Material Technology

What is metal? In chemistry, a metal is an element that readily forms positive ions (cations) and has

metallic bonds.

Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons.

The metals are one of the three groups of elements as distinguished by their ionization and bonding properties, along with the metalloids and nonmetals

or Metals are generally defined as being solid elements which share certain

physical, chemical and mechanical properties that differentiate them. Apart from their shine, malleability, ductility, hardness, resilience and elasticity, they are good conductors of heat and electricity, and have a high light reflection capacity.

Ferrous Metals

The following are ferrous metals and the kind of uses to which they are usually put:

Mild Steel – Carbon content of 0.1 to 0.3% and Iron content of 99.7 – 99.9%. Used for engineering purposes and in general, none specialised metal products.

Carbon steel – Carbon content of 0.6 to 1.4% and Iron content of 98.6 to 99.4 %. Used to make cutting tools such as drill bits.

Stainless Steel – Made up of Iron, nickel and chromium. Resists staining and corrosion and is therefore used for the likes of cutlery and surgical instrumentation. See our infographic celebrating 100 years of stainless steel usage in buildings or the different types of stainless steel.

Cast Iron – carbon 2 – 6% and Iron at 94 to 98%. Very strong but brittle. Used to manufacture items such as engine blocks and manhole covers.

Wrought Iron – Composed of almost 100% iron. Used to make items such as ornamental gates and fencing. Has fallen out of use somewhat

Non Ferrous Metals

These are the non ferrous metals and their uses:

Aluminium – An alloy of aluminium, copper and manganese. Very lightweight and easily worked. Used in aircraft manufacture, window frames and some kitchen ware.

Copper – Copper is a natural occurring substance. The fact that it conducts heat and electricity means that it is used for wiring, tubing and pipe work.

Brass – A combination of copper and zinc, usually in the proportions of 65% to 35% respectively. Is used for ornamental purposes and within electrical fittings.

Silver – Mainly a natural substance, but mixing with copper creates sterling silver. Used for decorative impact in jewellery and ornaments, and also to solder different metals together.

Lead – Lead is a naturally occurring substance. It is heavy and very soft and is often used in roofing, in batteries and to make pipes.

What is iron? Iron is a chemical element with the symbol (Fe) and atomic number 26. It is a

metal in the first transition series. It by mass is the most common element on Earth, forming much of Earth's outer and inner core.

Iron, one of the most abundant metals on Earth, is essential to most life forms and to normal human physiology. Iron is an integral part of many proteins and enzymes that maintain good health. In humans, iron is an essential component of proteins involved in oxygen transport. It is also essential for the regulation of cell growth and differentiation

What is steel? Steel is an alloy of iron, with carbon being the primary alloying element. The carbon content of steel is between 0.002% and 2.1% by weight. Too little carbon content leaves (pure) iron quite soft, ductile, and weak. Carbon contents higher than those of steel make an alloy commonly called pig iron that is brittle and not malleable.

Additional elements may be present in steel: manganese, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen and aluminium.

Alloy steel is steel to which additional alloying elements have been intentionally added to modify the characteristics of steel. Common alloying elements include: manganese, nickel, chromium, molybdenum, boron, titanium, vanadium and niobium

IRON & STEELIron making in the Blast Furnace Plant

Hearth Refractories

Tuyeres

Bustle Main

Refractory Lining

Throat Armour

Top Bins

Top Gas Mains

Above Burden Probe

Temperature Probe

Sub Burden Probe

Blast Furnace

(c) Coláiste L

orcain

10

6: Layers of sinter, iron oxide pellets, ore,7: Hot air (around 1200°C)8: Slag9: Liquid pig iron10: Mixers11: Tap for pig iron12: Dust cyclon for removing dust from exhaust gasses before burning them in 1313: air heater14: Smoke outlet (can be redirected to carbon capture & storage (CCS) tank)15: feed air for Cowper air heaters16: Powdered coal17: cokes oven18: cokes bin19: pipes for blast furnace gas

1: Iron ore + Calcareous sinter2: coke3: conveyor belt4: feeding opening, with a valve that prevents direct contact with the internal parts of the furnace5: Layer of coke

How is Steel made?

Steel products

Semi-finished products(continuous cast steel)

Finished products (rolled steel)

Iron-carbon Phase Diagram Iron-carbon phase diagram describes the iron-carbon system of alloys containing up to 6.67% of carbon, discloses the phases compositions and their transformations occurring with the alloys during their cooling or heating.

Carbon content 6.67% corresponds to the fixed composition of the iron carbide Fe3C.