Steel Plate and Sections GROUP D : Tarang Valecha Apurva Mali Dhananjay R Prateek Singh

Why is steel preferred as a basic ship building material? Refer to composition and properties in answering the above ?

An Introduction…. The ship of today is a large sturdy, self- Propelled vessels in which people transport Goods across,oceans,and lakes. It is the Productof countless centuries of Development. Among the first true boats was a fairly Simple frame of sticks, lashed together and Covered with sewn hides. Meanwhile iron gradually began to Supplement wood in ship construction. Although used experimentally by the British Before 1800,iron did not become a Significant shipbuilding material until after 1830.

An Introduction … Steel is the basic shipbuilding material in use today. Steel may be regarded as an iron- carbon alloy, usually containing other elements, the carbon content not usually exceeding 2%. Special steels of high tensile strength are used on certain highly stressed parts of the ship’s structure. Steel is readily available, of consistent Quality, and can be welded,forged and cast.

INGREDIENTS OF STEEL STEEL IRON ORECOKEFLUX MOLTEN IRON SCRAP STEEL ALLOYING MATERIALS

INGREDIENTS OF STEEL  IRON ORE Iron ore is a rock that contains iron combined with oxygen. It is sourced from mines around the world. Some of the world's highest quality iron ore comes from Australia  COKE Coke is made from coal. Once mined, the coal is crushed and washed. Coal is then baked in coke ovens for about 18 hours. During this process, by-products are removed and coke is produced.  FLUX Flux is a term which describes minerals used to collect impurities during iron and steelmaking. Fluxes include limestone and dolomite. The flux causes a chemical reaction and the elements not needed for steelmaking combine to form slag.

INGREDIENTS OF STEEL  MOLTEN IRON Iron is the main ingredient needed to make steel in the Basic Oxygen Steelmaking process. Molten iron is made from iron ore and other ingredients in a blast furnace.  SCRAP STEEL Scrap steel comes from many different sources because it is very easily recycled. Some scrap comes from within the Steelworks, where it might have been damaged or is at the end of a batch of one type of steel. It also comes from old car bodies, old ship containers and buildings that have been demolished.  ALLOYING MATERIALS Alloying materials are used to give the steel special properties and make different types of steel. Alloying materials can be added as elements, like manganese, aluminum and nickel, or as compounds of iron.

PROPERTIES OF STEEL LUSTRE It is a shiny metal with a very attractive finish (architecture, cutlery, appliances). CONDUCTIVITY It transfers heat and electricity. MALLEABILITY It can be rolled into thin sheets, rod, bar or beams (roofing, structural) or forged into different shapes (gears, tools). DUCTILITY It can be stretched and drawn out into thin wires (wire fences) or pressed into different shapes (auto body panels).

PROPERTIES OF STEEL STRENGTH It is very strong and resistant to fracture (building frames, security doors, trains, ships). DURABILITY It is a long lasting material (buildings, rail lines, bridges) and resistant to wear (machines and equipment). ALLOYING Adding other chemicals can change steel's properties. Stainless steel contains the elements chromium, nickel and molybdenum to make it rust resistant for use in kitchens. Manganese is added to increase toughness, while steel for rods has tungsten and cobalt to keep it hard, even when it gets hot. COATING As well as having various recipes, steel can also be coated with different substances, such as other metals like tin, or plastics or paint. ZINCALUME® steel has a protective coating of a zinc-aluminium alloy to protect it from the weather.

Production:  Acid or basic are terms often used when referring to steels.  The reference is to the production and the type of furnace fining eg: an alkaline or basic fining us used to produce basic steel.  The choice of furnace lining is dictated by the raw materials used in the manufacturing of the steel.  There are 3 particular processes currently used for the manufacture of carbon steel namely: - Open hearth process - Basic oxygen steel process - Electric furnace process  In all these processes the hot molten metal is exposed to air or oxygen, which oxidizes the impurities to refine the pig iron into high quality steel.

ADVANTAGES OF STEEL When you compare iron and steel with something like aluminum, you can see why it was so important historically. To refine aluminum, you must have access to huge amounts of electricity. To shape aluminum, you must either cast it or extrude it. Iron is much easier to deal with But right now, the economic equation gives inexpensive iron and steel a huge advantage over these much more expensive alternatives. Steel is iron that has most of the impurities removed. Steel also has a consistent concentration of carbon throughout (0.5 percent to 1.5 percent) The advantage of steel over iron is greatly improved strength. Most modern steel plants use what's called a basic oxygen furnace to create steel. The advantage is that it is a rapid process -- about 10 times faster than the open hearth furnace.basic oxygen furnace A variety of metals might be alloyed with the steel at this point to create different properties. For example, the addition of 10 percent to 30 percent chromium creates stainless steel, which is very resistant to rust. The addition of chromium and molybdenum creates chrome-moly steel, which is strong and light. The only real problem with iron and steel is rust. But you can control rust with paint, galvanizing, chrome plating or sacrificial anodes galvanizingsacrificial anodes

CONCLUSION  Owing to these advantages of steel they are a good structural material for ships. The various grades developed, constitute the best available material for ship building.  But right now, the economic equation gives inexpensive iron and steel a huge advantage over these much more expensive alternatives.  Advance in steel production and alloying methods have resulted in good higher strength steels for ship construction.  The basic raw material for steel is iron ore and huge availability of something as useful as iron ore is a big advantage. Also,the availability of vast quantities of oil and coal to power the production of iron.  Thus,steel is the basic ship building material in use today.