Steel making process
- 1. STEEL MAKING PROCESS PREPARED BY: TAIMOOR HASSAN PRESENTED BY (D-16-MME- 43,24,42,41,26) PRESENTED TO: IFTAKHAR MEMON
- 2. INTRODUCTION • Steelmaking is the process for producing steel from raw iron and scrap. • In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon are removed from the raw iron, and alloying elements such as manganese, nickel, chromium and vanadium are added to produce different grades of steel. • Limiting dissolved gases such as nitrogen and oxygen, and entrained impurities in the steel is also important to ensure the quality of the products cast from the liquid steel
- 3. PROCESS • Today there are two major commercial processes for making steel • basic oxygen steelmaking, • electric arc furnace
- 4. BASIC OXYGEN STEELMAKING • Around 71 % of steel is made by this process. • BOF process was developed in Austria in the early 1950s at the two Austrian steelworks at Linz and Donawitz and hence the BOF process is also called LD (first letters of the two cities) steel making. • basic oxygen steelmaking, which has liquid pig-iron from the blast furnace and scrap steel as the main feed materials • Modern furnaces, or ‘converters’ will take a charge of up to 350 tonnes and convert it into steel in around 15 minutes.
- 5. BASIC OXYGEN STEELMAKING • Blowing oxygen through molten pig iron lowers the carbon content of the alloy and changes it into low-carbon steel. The process is known as basic because fluxes of burnt lime or dolomite, which are chemical bases, are added to promote the removal of impurities and protect the lining of the converter. • The oxygen combines with carbon and other unwanted elements, eliminating them from the molten charge • These oxidation reactions produce heat, and the temperature of the metalis controlled by the quantity of added scrap. • The carbon leaves the converter as a gas, carbon monoxide, which can,after cleaning, be collected for re-use as a fuel.
- 6. ELECTRIC ARC FURNACE • electric-arc method, which uses high-current to melt steel scrap and convert it into liquid steel of a specified chemical composition. • The major charge material of electric-arc steelmaking is scrap steel, and its availability at low cost and proper quality is essential
- 7. ELECTRIC ARC FURNACE • Most scrap yards keep various grades of scrap separated. High- alloy shops, such as stainless-steel producers, accumulate. • The electric arc furnace consists of a circular bath with a movable roof, through which three graphite electrodes can be raised or lowered. • Lime and fluorspar are added as fluxes and oxygen is blown into the melt. As a result, impurities in the metal combine to form a liquid slag • electric-arc steels normally have carbon contents higher than
- 8. TYPES OF STEEL/PROPERTIES/APPLICATIONS • There are More Than 3,500 Different Grades of Steel • Different types of steel are produced according to the properties required for their application, • According to the American Iron and Steel Institute (AISI), steel can be broadly categorized into four groups based on their chemical compositions: 1. Carbon Steels 2. Alloy Steels 3. Stainless Steels 4. Tool Steels
- 9. CARBON STEEL • Carbon steels contain trace amounts of alloying elements and account for 90% of total steel production. Carbon steels can be further categorized into three groups depending on their carbon content: • Low Carbon Steels/Mild Steels contain up to 0.3% carbon • Medium Carbon Steels contain 0.3 – 0.6% carbon • High Carbon Steels contain more than 0.6% carbon • Uses in (Shafts and Gearing, Railway Applications, knives, pipe, etc
- 10. ALLOY STEELS Alloy steels contain alloying elements (e.g. manganese, silicon, nickel, titanium, copper, chromium, and aluminum) in varying proportions in order to manipulate the steel's properties, such as its hardenability, corrosion resistance, strength, formability, weldability or ductility. • Applications for alloys steel include pipelines, auto parts, transformers, power generators and electric motors
- 11. STAINLESS STEELS • Stainless steels generally contain between 10-20% chromium as the main alloying element and are valued for high corrosion resistance. With over 11% chromium, steel is about 200 times more resistant to corrosion than mild steel. These steels can be divided into three groups based on their crystalline structure: • Uses (Architecture and construction, Automotive, Medical)
- 12. TOOL STEELS • Tool steels contain tungsten, molybdenum, cobalt and vanadium in varying quantities to increase heat resistance and durability, making them ideal for cutting and drilling equipment.
- 13. REFERENCES • https://en.wikipedia.org/wiki/Steelmaking#Primary_steelmakin g • https://en.wikipedia.org/wiki/Electric_arc_furnace • https://en.wikipedia.org/wiki/Basic_oxygen_steelmaking • https://www.britannica.com/technology/steel/Electric-arc- steelmaking • https://sciencing.com/properties-uses-steel-7271721.html • https://www.thebalance.com/steel-grades-2340174 • https://www.metalsupermarkets.com/most-common-uses-of- stainless-steel/