TYPES OF STEEL

Other Chapters

• Q1: Define Steel.
  Ans: Steel is an alloy of iron and carbon.
  It contains a small percentage of carbon and is stronger than iron.
• Q2: What is the percentage of Carbon in steel?
  Ans: Steel contains about 0.1% to 1.5% carbon.
• Q3: Write the composition of Steel.
  Ans: The composition of steel is:

  • ➔ Iron (Fe): 98% to 99%
  • ➔ Carbon (C): 0.1% to 1.5%
  • ➔ Small amounts of manganese, silicon, sulfur, and phosphorus
• Q4: State the properties of Steel.
  Ans: The properties are:

  • ➔ High strength
  • ➔ Good hardness
  • ➔ Ductile and malleable (depending on type)
  • ➔ Can be heat treated
  • ➔ Good machinability
• Q5: State the uses of Steel.
  Ans: The uses are:

  • ➔ Construction of buildings and bridges
  • ➔ Automobile industry
  • ➔ Machinery and tools
  • ➔ Railway tracks
• Q6: What is the annual production of steel in the world?
  Ans: The world annual steel production is approximately 1.8 to 2.0 billion tons.
• Q7: State the types of Steel.
  Ans: The types are:

  • ➔ Plain Carbon Steel
  • ➔ Alloy Steel
• Q8: What is Iron?
  Ans: Iron is a metallic element with symbol Fe.
  It is widely used in engineering due to its strength and availability.
• Q9: Write the composition of Iron.
  Ans: Pure iron is mainly composed of iron element only.
  It may contain small traces of carbon and other impurities depending on its form.
• Q10: State the properties of Iron.
  Ans: The properties are:

  • ➔ Magnetic in nature
  • ➔ High strength
  • ➔ Good ductility
  • ➔ Corrodes easily (rusting)
  • ➔ High melting point
• Q11: State the uses of Iron.
  Ans: The uses are:

  • ➔ Construction of buildings
  • ➔ Machinery parts
  • ➔ Automobile industry
  • ➔ Tools and equipment
• Q12: What is the annual production of Iron in the world?
  Ans: The world annual production of iron (mainly in steel form) is about 1.8 to 2.0 billion tons.
• Q13: State the types of Iron.
  Ans: The types of iron are:

  • ➔ Pig Iron
  • ➔ Cast Iron
  • ➔ Wrought Iron
• Q14: What is the percentage of Carbon in Iron?
  Ans: Pure iron contains almost 0% carbon.
  In industrial forms, carbon content varies depending on type of iron.
• Q15: What is Pig Iron? State its composition.
  Ans: Pig iron is the crude form of iron obtained from a blast furnace.
  Its composition is:

  • ➔ Iron (Fe): 92% to 95%
  • ➔ Carbon (C): 3% to 4%
  • ➔ Silicon, sulfur, phosphorus: small amounts
• Q16: State the uses of Pig Iron.
  Ans: The uses are:

  • ➔ Manufacturing cast iron
  • ➔ Steel production
  • ➔ Foundry work
• Q17: What is Cast Iron? State its composition.
  Ans: Cast iron is an alloy of iron and carbon with high carbon content.
  Its composition is:

  • ➔ Iron (Fe): 92% to 94%
  • ➔ Carbon (C): 2% to 4%
  • ➔ Silicon: 1% to 3%
• Q18: State the uses of Cast Iron.
  Ans: The uses are:

  • ➔ Machine beds
  • ➔ Pipes and fittings
  • ➔ Engine blocks
  • ➔ Manhole covers
• Q19: What is Wrought Iron? State its composition.
  Ans: Wrought iron is a very pure form of iron with very low carbon content.
  Its composition is:

  • ➔ Iron (Fe): about 99%
  • ➔ Carbon (C): less than 0.1%
  • ➔ Slag: small amount
• Q20: State the uses of Wrought Iron.
  Ans: The uses are:

  • ➔ Chains and hooks
  • ➔ Decorative items
  • ➔ Pipes and tubes
  • ➔ Agricultural tools
• Q21: State the difference between Steel and Iron.
  Ans: The differences are:

  • ➔ Steel contains carbon (0.1% to 1.5%), iron is pure or nearly pure
  • ➔ Steel is stronger than iron
  • ➔ Steel is more durable and corrosion resistant
  • ➔ Iron is softer and less strong
• Q22: What is Plain Carbon Steel?
  Ans: Plain carbon steel is a type of steel that contains only iron and carbon as main elements.
  It does not contain significant alloying elements.
• Q23: State the uses of Plain Carbon Steel.
  Ans: The uses are:

  • ➔ Construction work
  • ➔ Machine parts
  • ➔ Tools and equipment
  • ➔ Structural applications
• Q24: State the properties of Plain Carbon Steel.
  Ans: The properties are:

  • ➔ Strength depends on carbon content
  • ➔ Good machinability
  • ➔ Can be heat treated
  • ➔ Prone to corrosion
• Q25: State the types of Plain Carbon Steel.
  Ans: The types are:

  • ➔ Mild Steel
  • ➔ Medium Carbon Steel
  • ➔ High Carbon Steel
• Q26: What is Mild Steel? State the composition.
  Ans: Mild steel is a low carbon steel that is soft and easily workable.
  Its composition is:

  • ➔ Iron (Fe): 99%
  • ➔ Carbon (C): 0.05% to 0.25%
• Q27: Write the uses of Mild Steel.
  Ans: The uses are:

  • ➔ Structural work
  • ➔ Automobile bodies
  • ➔ Pipes and tubes
  • ➔ Nuts and bolts
• Q28: State the properties of Mild Steel.
  Ans: The properties are:

  • ➔ Highly ductile
  • ➔ Good weldability
  • ➔ Soft and tough
  • ➔ Low strength compared to other steels
• Q29: What is Dead Mild Steel? State the composition.
  Ans: Dead mild steel is the lowest carbon steel with very high ductility.
  Its composition is:

  • ➔ Iron (Fe): about 99.5%
  • ➔ Carbon (C): 0.05% or less
• Q30: State the uses of Dead Mild Steel.
  Ans: The uses are:

  • ➔ Deep drawing sheets
  • ➔ Automobile panels
  • ➔ Roofing sheets
• Q31: State the properties of Dead Mild Steel.
  Ans: The properties are:

  • ➔ Very high ductility
  • ➔ Excellent formability
  • ➔ Very soft
  • ➔ Low strength
• Q32: What is Medium Carbon Steel? State the composition.
  Ans: Medium carbon steel contains moderate carbon content.
  Its composition is:

  • ➔ Iron (Fe): balance
  • ➔ Carbon (C): 0.25% to 0.6%
• Q33: State the uses of Medium Carbon Steel.
  Ans: The uses are:

  • ➔ Gears
  • ➔ Shafts
  • ➔ Railway wheels
  • ➔ Machine parts
• Q34: State the properties of Medium Carbon Steel.
  Ans: The properties are:

  • ➔ Moderate strength
  • ➔ Good toughness
  • ➔ Can be heat treated
  • ➔ Less ductile than mild steel
• Q35: What is High Carbon Steel? State the composition.
  Ans: High carbon steel contains high percentage of carbon.
  Its composition is:

  • ➔ Iron (Fe): balance
  • ➔ Carbon (C): 0.6% to 1.5%
• Q36: State the uses of High Carbon Steel.
  Ans: The uses are:

  • ➔ Cutting tools
  • ➔ Knives and blades
  • ➔ Springs
  • ➔ High strength wires
• Q37: State the properties of High Carbon Steel.
  Ans: The properties are:

  • ➔ Very high hardness
  • ➔ High strength
  • ➔ Low ductility
  • ➔ Brittle in nature
• Q38: What are Alloy Steels?
  Ans: Alloy steels are steels that contain iron and carbon along with other alloying elements such as nickel, chromium, manganese, or tungsten.
  These elements improve the mechanical and chemical properties of steel.
• Q39: State the properties of Alloy Steels.
  Ans: The properties are:

  • ➔ High strength and hardness
  • ➔ Better corrosion resistance
  • ➔ Improved wear resistance
  • ➔ Can withstand high temperature
  • ➔ Good toughness
• Q40: State the uses of Alloy Steels.
  Ans: The uses are:

  • ➔ Aircraft and automobile parts
  • ➔ Cutting tools
  • ➔ Machine components
  • ➔ Construction of heavy structures
• Q41: State the types of Alloy Steels.
  Ans: The types are:

  • ➔ Nickel Steel
  • ➔ Chromium Steel
  • ➔ Nickel Chromium Steel
  • ➔ Manganese Steel
  • ➔ Tungsten Steel
• Q42: What is Nickel Steel?
  Ans: Nickel steel is an alloy steel in which nickel is the main alloying element added to iron and carbon.
  It improves strength and toughness.
• Q43: State the uses of Nickel Steel.
  Ans: The uses are:

  • ➔ Aircraft parts
  • ➔ Automobile components
  • ➔ Armor plates
• Q44: What is Chromium Steel?
  Ans: Chromium steel is an alloy steel that contains chromium as the main alloying element.
  It increases hardness and corrosion resistance.
• Q45: State the uses of Chromium Steel.
  Ans: The uses are:

  • ➔ Cutting tools
  • ➔ Bearings
  • ➔ Surgical instruments
• Q46: What is Nickel Chromium Steel?
  Ans: Nickel chromium steel is an alloy steel containing both nickel and chromium.
  It has excellent strength, toughness, and corrosion resistance.
• Q47: State the uses of Nickel Chromium Steel.
  Ans: The uses are:

  • ➔ Automobile parts
  • ➔ Aircraft components
  • ➔ High strength machine parts
• Q48: What is Manganese Steel?
  Ans: Manganese steel is an alloy steel containing high percentage of manganese.
  It is very tough and wear resistant.
• Q49: State the uses of Manganese Steel.
  Ans: The uses are:

  • ➔ Railway tracks
  • ➔ Rock crushers
  • ➔ Mining equipment
• Q50: What is Tungsten Steel?
  Ans: Tungsten steel is an alloy steel that contains tungsten as an alloying element.
  It maintains hardness at high temperatures.
• Q51: State the uses of Tungsten Steel.
  Ans: The uses are:

  • ➔ Cutting tools
  • ➔ Drills and bits
  • ➔ High-speed tools
• Q52: What is Molybdenum Steel?
  Ans: Molybdenum steel is an alloy steel in which molybdenum is added to iron and carbon.
  It increases strength, hardness, and heat resistance of steel.
• Q53: State the uses of Molybdenum Steel.
  Ans: The uses are:

  • ➔ Aircraft parts
  • ➔ Pressure vessels
  • ➔ Automotive components
  • ➔ High temperature tools
• Q54: What is Vanadium Steel?
  Ans: Vanadium steel is an alloy steel that contains vanadium as an important alloying element.
  It improves strength, toughness, and wear resistance.
• Q55: State the uses of Vanadium Steel.
  Ans: The uses are:

  • ➔ Automobile springs
  • ➔ Gears and shafts
  • ➔ Cutting tools
• Q56: What is Silicon Steel?
  Ans: Silicon steel is an alloy steel that contains silicon as a major alloying element.
  It improves electrical and magnetic properties of steel.
• Q57: State the uses of Silicon Steel.
  Ans: The uses are:

  • ➔ Transformer cores
  • ➔ Electric motors
  • ➔ Electrical generators
• Q58: What are High Speed Tool Steels?
  Ans: High speed tool steels are special alloy steels that can cut materials at high speeds without losing hardness.
  They retain hardness even at high temperatures.
• Q59: Name the types of High Speed Tool Steels.
  Ans: The types are:

  • ➔ Tungsten based HSS
  • ➔ Molybdenum based HSS
  • ➔ Cobalt (super) HSS
  • ➔ Vanadium HSS
• Q60: What is High Speed Steel?
  Ans: High speed steel is a tool steel that can cut at high cutting speeds without losing hardness due to heat.
  It contains elements like tungsten, chromium, and vanadium.
• Q61: State the uses of High Speed Steel
  Ans: The uses are:

  • ➔ Drills
  • ➔ Milling cutters
  • ➔ Lathe tools
  • ➔ Saw blades
• Q62: What is Molybdenum High Speed Steel?
  Ans: Molybdenum high speed steel is a type of HSS in which molybdenum replaces part of tungsten.
  It provides similar hardness with lower cost.
• Q63: State the uses of Molybdenum High Speed Steel
  Ans: The uses are:

  • ➔ Cutting tools
  • ➔ Drills and taps
  • ➔ Machine tools
• Q64: What is Super High Speed Steel?
  Ans: Super high speed steel is an advanced tool steel containing cobalt.
  It has higher heat resistance and cutting ability than normal HSS.
• Q65: State the uses of Super High Speed Steel.
  Ans: The uses are:

  • ➔ High-speed cutting tools
  • ➔ Heavy-duty machining tools
  • ➔ Aerospace tools
• Q66: What is Vanadium High Speed Steel?
  Ans: Vanadium high speed steel is a type of HSS that contains vanadium as an important alloying element.
  It improves wear resistance and grain structure.
• Q67: State the uses of Vanadium High Speed Steel.
  Ans: The uses are:

  • ➔ Cutting tools
  • ➔ Drills and reamers
  • ➔ Precision machining tools
• Q68: What is Stainless Steel?
  Ans: Stainless steel is an alloy steel that contains iron, carbon, and a high percentage of chromium.
  It is known for its corrosion resistance.
• Q69: State the uses of Stainless Steel.
  Ans: The uses are:

  • ➔ Kitchen utensils
  • ➔ Medical instruments
  • ➔ Construction work
  • ➔ Chemical equipment
• Q70: State the properties of Stainless Steel.
  Ans: The properties are:

  • ➔ High corrosion resistance
  • ➔ High strength
  • ➔ Good appearance (shiny surface)
  • ➔ Heat resistance
• Q71: State the types of Stainless Steel
  Ans: The types are:

  • ➔ Austenitic Stainless Steel
  • ➔ Ferritic Stainless Steel
  • ➔ Martensitic Stainless Steel
• Q72: What is Austenitic Stainless Steel?
  Ans: Austenitic stainless steel contains high chromium and nickel.
  It has excellent corrosion resistance and non-magnetic nature.
• Q73: State the uses of Austenitic Stainless Steel.
  Ans: The uses are:

  • ➔ Food processing equipment
  • ➔ Chemical industry equipment
  • ➔ Kitchen appliances
• Q74: What is Ferritic Stainless Steel?
  Ans: Ferritic stainless steel contains high chromium and low carbon.
  It has magnetic properties and good corrosion resistance.
• Q75: State the uses of Ferritic Stainless Steel
  Ans: The uses are:

  • ➔ Automotive parts
  • ➔ Industrial equipment
  • ➔ Kitchen appliances
• Q76: What is Martensitic Stainless Steel?
  Ans: Martensitic stainless steel contains higher carbon content.
  It is hard and can be heat treated.
• Q77: State the uses of Martensitic Stainless Steel.
  Ans: The uses are:

  • ➔ Cutting tools
  • ➔ Surgical instruments
  • ➔ Turbine blades
• Q78: What are Alloying elements?
  Ans: Alloying elements are elements added to steel to improve its properties such as strength, hardness, and corrosion resistance.
  Examples include chromium, nickel, and manganese.
• Q79: State the effects of Alloying elements on Steel.
  Ans: The effects are:

  • ➔ Increase strength and hardness
  • ➔ Improve corrosion resistance
  • ➔ Improve heat resistance
  • ➔ Improve wear resistance
• Q80: State some Alloying elements.
  Ans: The alloying elements are:

  • ➔ Chromium
  • ➔ Nickel
  • ➔ Manganese
  • ➔ Tungsten
  • ➔ Vanadium
• Q81: State the uses of Tungsten.
  Ans: The uses are:

  • ➔ High speed cutting tools
  • ➔ Filaments in bulbs
  • ➔ Drilling tools
• Q82: State the uses of Cobalt.
  Ans: The uses are:

  • ➔ Super alloys
  • ➔ Cutting tools
  • ➔ Magnetic materials
• Q83: What is Eutectoid Steel?
  Ans: Eutectoid steel is steel that contains about 0.8% carbon.
  It transforms completely into pearlite on cooling.
• Q84: State the uses of Eutectoid Steel.
  Ans: The uses are:

  • ➔ Springs
  • ➔ Cutting tools
  • ➔ Wires
• Q85: What is Cementite?
  Ans: Cementite is iron carbide (Fe₃C).
  It is very hard and brittle.
• Q86: What is Pearlite?
  Ans: Pearlite is a mixture of ferrite and cementite.
  It has a layered structure and medium hardness.
• Q87: What is Austenite?
  Ans: Austenite is a solid solution of carbon in gamma iron.
  It is non-magnetic and stable at high temperatures.
• Q88: What are Intermetallic Compounds? Name some.
  Ans: Intermetallic compounds are compounds formed between two or more metals with a definite structure.
  Examples include:

  • ➔ FeAl
  • ➔ Ni₃Al
  • ➔ CuZn
• Q89: What is AISI Code?
  Ans: AISI code is a classification system used by the American Iron and Steel Institute.
  It identifies different types of steels using numerical codes.
• Q90: State the Code Numbers of Steels.
  Ans: The AISI steel code numbers are:

  • ➔ 10xx: Plain carbon steel
  • ➔ 41xx: Chromium-molybdenum steel
  • ➔ 43xx: Nickel-chromium-molybdenum steel
  • ➔ 52xx: Bearing steel