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.
