1. ZUBAIR AHMAD UNITED GULF STEEL ZUBAIR AHMAD UNITED GULF STEEL

2. Rolling (Hot/Cold) Mechanical Working = Permanent Deformation = Mechanical Working Is a permanent deformation to which metal is subjected to change its shape and/or properties.

3. Reheating Roughing Finishing Cooling Coiling Grain Refinement Recrystallization Grain Refinement Precipitation Austenite Decomposition Accelerated Cooling Precipitation Phase transformation > 1200 °C Austenitizing Slab Chemistry Thickness & Temperature Reduction Chemistry (C, Mn, Ni, Cu, MAE)

4. Strength Ductility Toughness Weldability Sour Resistance …etc Steel Mechanical Properties CVN DWTT PSL2: YS (min/max) UTS (min/max) YS/UTS CE Pcm HIC SSCC

5. 5 Steel Mechanical Properties Chemistry Processing Parameters

6. وَأَنْزَلْنَا الْحَدِيدَ فِيهِ بَأْسٌ شَدِيدٌ وَمَنَافِعُ لِلنَّاسِ Basic Metallurgy 1- Meteoric Iron (5 – 30 % nickel) Limited Rare (Grains or nodules of Iron in basalt that erupted through beds of coal) (Use charcoal to reduce iron from its oxides) 3- Man-made Ferrous Metals. 2- Telluric (Native) Iron Fe 2 O 3 + 3CO → 2Fe + 3 CO 2

7. Iron is so important that primitive societies are measured by the point at which they learn how to refine iron and enter the iron age! Gold is for the mistress …. silver for the maid Copper for the craftsman cunning at his trade. Iron "But Iron … Cold Iron … is master of them all !“ Rudyard Kipling, 1910 Basic Metallurgy

8. Strong materialStrong material Easy to shapeEasy to shape Conduct heat and electricityConduct heat and electricity Unique magnetic propertiesUnique magnetic properties Iron is plentiful (5% of the Earth's crust)Iron is plentiful (5% of the Earth's crust) Relatively easy to refineRelatively easy to refine Iron Basic Metallurgy

9. Iron ores Iron ores are rocks that contain a high concentration of iron Hematite - Fe 2 O 3 - 70 % iron Magnetite - Fe 3 O 4 - 72 % iron Limonite - Fe 2 O 3 + H 2 O - 50 % to 66 % iron Siderite - FeCO 3 - 48 % iron Hematite Basic Metallurgy

10. Grains Crystal Structure Basic Metallurgy

11. X Y Z Space Lattice: A collection of points that divided space into smaller sized segments. Unit Cell: A subdivision of the lattice that still retains the overall characteristics of the entire lattice. Crystal Structure (Atomic Arrangement) Basic Metallurgy Atom

12. Formation of Polycrystalline Material Liquid ab c d Solid (Unit Cell) Grain Boundaries a) Small crystalline nuclei b) Growth of Crystals c) Irregular grain shapes formed upon completion of solidification d) Final grain structure Grain Boundary: The zone of crystalline mismatch between adjacent grains. The lattice has different orientation on either side of the grain boundary Basic Metallurgy

13. Grain Boundary

14. BCC - Delta Iron (  ) FCC - Gamma Iron (  ) BCC - Alpha Iron (  ) Temperature 1540 o C 1400 o C 910 o C Atomic Packing in Iron (Allotropic) Basic Metallurgy

15. Body Centered Cubic (BCC) Alpha & Delta Iron ( ,  ) Total 2 Atoms/Unit Cell α Lattice Parameter (a) = 0.287 nm δ Lattice Parameter (a) = 0.293 nm a Squared Packed Layer Basic Metallurgy

16. Face Centered Cubic (FCC) Gamma Iron (  ) Total 4 Atoms/Unit Cell  Lattice Parameter (a) = 0.359 nm a Close Packed Layer Basic Metallurgy

17. High Dense Atomic Packing Slip Distance Effect of the Atomic Packing in Deformation Behavior Displacement Slip Distance Displacement Low Dense Atomic Packing Slip occurs easily on closest packed plane (high atomic packing density) along the closest packed direction where the slip distance is minimum. Basic Metallurgy

18. Smooth Surface Easy to slip with minimum power Example of closed Packed planes Uneven Surface Relatively high energy is required for limited slip Example of squared packed plans Rough Surface Extremely hard to slip Example of squared packed plans with high inter-atom spaces Basic Metallurgy Effect of the Atomic Packing in Deformation Behavior

19. STEEL = IRON + Alloying Elements ( C + Mn, Si, Ni, …) IRON + < 2 % Carbon = STEEL IRON + > 2 % Carbon = CAST IRON What is the difference between “STEEL” and “CAST IRON” ? Basic Metallurgy

20. Solid Solution Solid Homogenous Mixture of Elements with at least One Metal –Solute Dissolves in Base Metal No Visible Signs of Presence –Structure & Metallic Characteristics as those of Base Metal –Hardness Increases with Solution Distortion of Lattice Structure Basic Metallurgy

21. Interstitial Atoms Small solute atoms (e.g. Carbon in Iron) that sit in the space between parent atoms. Substitutional Atoms Large solute atoms (e.g. Tin in Iron) that occupy the same sit as the parent atoms. Be Si Sn Al Ni Zn Alloying Elements % 100 - 300 - 200 - 10 3020 Yield Strength (MPa) Solid Solution Hardening Basic Metallurgy

22. Liquid (L) (  +  Fe 3 C  ) (  +  L  ) Austenite (  ) 1540 1495 1150 °C 727 °C 910 0.5% 0.18% 0.1% Cementite (Fe 3 C)+ Pearlite (  +  ) ( +L) ( +L) Steel Cast Iron 4.3% 2.1% Eutectic Ferrite + Pearlite Ferrite (  ) Weight Percentage Carbon Temperature ( o C) 1000 - 1200 - 1400 - 1600 - 1.0 800 - 4.0 3.0 2.0 6.67 400 - 600 - 200 - 0 - Hypoeutectoid Hypereutectoid Hypereutectic Hypoeutectic 0.8% Eutectoid Delta Ferrite (  ) (  ) Peritectic Iron Carbon Phase Diagram

23. Atomic Packing in Iron (Allotropic) BCC - Delta Iron (  ) FCC - Gamma Iron (  ) BCC - Alpha Iron (  ) Basic Metallurgy

24. Weight Percentage Carbon Temperature ( o C) (  +  Fe 3 C  ) (  +  L  ) Austenite (  ) Liquid (L) 1540 1495 727 °C 910 Cementite (Fe 3 C)+ Pearlite (  +  ) Ferrite + Pearlite Ferrite (  ) 1000 - 1200 - 1400 - 1600 - 1.0 800 - 2.0 400 - 600 - 200 - 0 - 0.8% Eutectoid Delta Ferrite (  ) (  ) Peritectic ( +L) ( +L) 1150 °C Ferrite Cementite ~0% C 0.2% C 0.35% C 0. 5% C 0. 7% C 0. 8% C 1.2% C

25. Strength: Ability to withstand loads (Tensile & Compressive Strength) Ductility: Ability to deform under tensile loads without rupture Bending Ability Ability to bend without Fracture Toughness Ability to absorb energy in shock loading (Impact Strength) Hardness Resistance to penetration Weldability Ability to be welded without cracking Fundamental Mechanical Properties Basic Metallurgy

26. Carbon (C):  Strength & Hardness  Ductility, Malleability & Weldability Silicon (Si): Manganese (Mn): De-oxidizer,  Strength, Hardenability & Impact Strength De-oxidizer,  Strength & Toughness  Hardenability Aluminum (Al): Strong De-oxidizer,  Grain Refinement   Strength & Toughness MAE (V, Ti & Nb): Sulfur (S): Harmful  Ductility, Weldability Strength & Impact Strength  Grain Refinement   Strength, Hardenability & Toughness Basic Metallurgy Effect of Alloying Elements

27. Stress – Vs - Strain L1L1 F L1L1 Force (F) LoLo  = F/A o Stress: Force per unit area Measuring the internal resistance of the body. Strain: Unit deformation Measuring the change in dimensions of the body  = (L 1 – L o )/L o Basic Metallurgy

28. Elastic Def. Plastic Deformation O P Strain Stress P: Elastic Limit Y: Yield Point S: Max. Load Value B: Breaking Point P: Elastic Limit Y: Yield Point S: Max. Load Value B: Breaking Point Y S B Basic Metallurgy Stress – Vs - Strain

29. Elastic & Plastic Deformation Elastic Deformation: Deformation of a material that recovered when the applied load is removed. This type of deformation involves stretching of the bonds without permanent atomic displacement. Plastic Deformation: Permanent deformation of a material that is not recovered when the applied load is removed. This Type of deformation involves breaking of a limited number of atomic bonds. Basic Metallurgy

30. Microstructural Defects Theoretical yield strength predicted for perfect crystals is much greater than the measured strength. The existence of defects explains the difference. Which is easier to cut? Basic Metallurgy

31. Braking all atomic bonds at once requires grater energy in perfect crystal Basic Metallurgy

32. 1) Point defects: a) vacancies, b) interstitial atoms, c) small substitional atoms, d) large substitional atoms, … etc. 2) Surface defects: Imperfections, such as grain boundaries, that form a two- dimensional plane within the crystal. Microstructural Defects Basic Metallurgy

33. 3) Line defects: dislocations (edge, screw, mixed) Dislocation: A line imperfection in the lattice or crystalline material Movement of dislocations helps to explain how materials deform. Interface with movement of dislocations helps explain how materials are strengthened. They are typically introduced into the lattice during solidification of the material or when the material is deformed. Microstructural Defects Basic Metallurgy

34. Motion of Dislocation When a shear stress is applied to the dislocation in (a), the atoms displaced, causing the dislocation to move one step (Burger’s vector) in the slip (b). Continued movement of the dislocation eventually creates a step (deformation) direction (C) Basic Metallurgy

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