1. MECHANICAL ENGINEERING MATERIALS
(1625304)
UNIT-2: Ferrous Metals and Alloys
Alloy steel, Effects of Alloying Element in Steel,
Application of some alloys
Er. Prakash Kumar
Lecturer
Department of Mechanical Engineering
Government Polytechnic Katihar
Department of Science and Technology
Patna, Bihar
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2. MECHANICAL ENGINEERING MATERIALS (1625304)
• UNIT-1 : Engineering Materials and their Properties
• UNIT-2 : Ferrous Metals and Alloys
• UNIT-3 : Non Ferrous Metals and Alloys
• UNIT-4 : Heat Treatment of Steels
• UNIT-5 : Non Metallic Materials
• UNIT-6 : Powder Metallurgy & Nondestructive Testing
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3. MECHANICAL ENGINEERING MATERIALS (1625304)
UNIT-2 : Ferrous Metals and Alloys
18 Marks
• Module-1 : Characteristics and application of ferrous metals
• Module-2 : Phase equilibrium diagram for Iron and Iron Carbide.
• Module-3 : Flow diagram for production of Iron and Steel, Classification, composition
and uses of cast iron, effect of sulphur, silicon and phosphorous.
• Module-4 : Classification, composition and application of low carbon steel, medium
carbon steel and high carbon steel with their chemical composition.
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4. MECHANICAL ENGINEERING MATERIALS (1625304)
UNIT-2 : Ferrous Metals and Alloys
18 Marks
• Module-5 : Alloy Steels: - Low alloy steel, high alloy steel, tools steel & stainless steel.
Effect of various alloying elements such as – Chromium, nickel, manganese,
molybdenum, tungsten, vanadium.
• Module-6 : Tool Steels: - High speed Steels (HSS), Hot & cold Working dies, shear,
punches etc., properties & applications.
• Module-7 : Magnetic materials: - Properties & Applications of commonly used
magnetic materials (Permanent magnets and temporary magnets).
• Module-8 : Special Cutting Tool Materials – Diamond, Stelites & Tungsten Carbide.
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High Strength Structural Steel (HSLA)
• Example - HSLA (high strength low alloy) steels
• They can be strengthened by heat treatment
• Ductile and formable.
• Alloying addition Cu, V, W, Ni. Cr. Mo,etc.
• Typical applications: support columns pressure vessels, bridge beams.
Tool Steels
• General properties are: Wear and abrasion resistance, toughness, red hardness,
non-deforming property and minimum cost.
Alloy Steel
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Stainless steels
• They typical consists min 12% Cr along with other alloying elements, thus
highly corrosion resistant owing to presence of chromium oxide.
• Typical applications cutlery, surgical knives, storage tanks, domestic items.
• Ferritic steels are principally Fe-Cr-C alloys with 12-14% Cr. And small
additions of Mo. V. Nb, Ni.
• Ferritic and austenitic steels are hardened and strengthened by cold work
because they are not heat treatable .
• Austenitic steels are non-magnetic as against ferritic and martensitic steels,
which are magnetic
Alloy Steel Contd….
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Effects of Alloying Element in Steel
• Sulphur: Machinability
• Molybdenum: Forms abrasion resisting particles/Improves creep properties
• Phosphorous: Improves machinability in free cutting steel.
• Cobalt: Contributes to red hardness by hardening ferrite.
• Chromium: Corrosion resistance/Increase hardness.
• Nickel: Hardenability
• Tungsten: Heat resistance, hot hardness
• Silicon: Magnetic permeability/Increase resistance to high temperature oxidation,
increases oxidation resistance
• Vanadium: Hardenability/Increases strength.
• Manganese: Hardness.
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Alloys Application
Monel metal [Ni (70%)+ Cu (30%)] Marine bearing
Invar (Nickel) [Ni (36%)+ Fe (64%)] Thermal expansion
Gun metal [Cu (88%), Sn (10%),Zn (2%)] Journal Bearing
German Silver (Cu, Zn, Ni, Pb, Sn) Electronics Industries
Babbit alloy (Cu, Sn, Pb) Bearing
Low carbon steel (Mild Steel) Wire nails, crane hooks
Medium carbon steel Screw. shaft and axes
High carbon steel Commercial beams, springs,cold chisels
Application of some alloys
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Alloys Application
Hadfield Mn steel Buldozer rolls
Constantan (Cu,Ni) Thermocouple
Chromal Thermocouple wire
Nimonic alloy Gas turbine blades
High speed steel (HSS) T-series [W(18%), Cr (4%), V(1%)] Cutting tool, Milling cutter
High speed steel (HSS) M-series [Mo(18%), Cr (4%), V(1%)] Cutting tool, Milling cutter
Tool Steel Making dies, ballbearing
Silicon steel Transformer lamination
Red brass Radiator
Application of some alloys Contd…
