FUNDAMENTALS OF METAL FORMING  <ul><li>Overview of Metal Forming </li></ul><ul><li>Material Behavior in Metal Forming </li...
Metal Forming <ul><li>Large group of manufacturing processes in which plastic deformation is used to change the shape of m...
Stresses in Metal Forming <ul><li>Stresses to plastically deform the metal are usually  compressive </li></ul><ul><ul><li>...
Material Properties in Metal Forming <ul><li>Desirable material properties:  </li></ul><ul><ul><li>Low  yield strength  an...
Temperature in Metal Forming  <ul><li>Any deformation operation can be accomplished with lower forces and power at elevate...
Hot Working <ul><li>Deformation at temperatures above  recrystallization temperature   </li></ul><ul><li>Recrystallization...
Why Hot Working? <ul><li>Capability for substantial plastic deformation of the metal ‑ far more than possible with cold wo...
Warm Working <ul><li>Performed at temperatures above room temperature but below recrystallization temperature </li></ul><u...
Advantages of Warm Working <ul><li>Lower forces and power than in cold working </li></ul><ul><li>More intricate work geome...
Advantages of Hot Working vs. Cold Working <ul><li>Workpart shape can be significantly altered </li></ul><ul><li>Lower for...
Disadvantages of Hot Working <ul><li>Lower dimensional accuracy </li></ul><ul><li>Higher total energy required (due to the...
Cold Working <ul><li>Performed at room temperature or slightly above  </li></ul><ul><li>Many cold forming processes are im...
HOT WORKING OPERATIONS <ul><li>FORGING </li></ul><ul><li>ROLLING </li></ul><ul><li>WELDING </li></ul><ul><li>EXTRUSION </l...
COLD WORKING OPERATIONS <ul><li>COLD ROLLING </li></ul><ul><li>EXTRUSION </li></ul><ul><li>PRESSING  </li></ul><ul><li>DEE...
Figure 18.2 – Basic bulk deformation processes:  (a) rolling
Figure 18.2 – Basic bulk deformation processes:  (b) forging
Figure 18.2 – Basic bulk deformation processes: (c) extrusion
Figure 18.2 – Basic bulk deformation processes:  (d) drawing
Sheet Metalworking <ul><li>Forming and related operations performed on metal sheets, strips, and coils </li></ul><ul><li>H...
Figure 18.3 ‑ Basic sheet metalworking operations: (a) bending
Figure 18.3 ‑ Basic sheet metalworking operations: (b) drawing
Figure 18.3 ‑ Basic sheet metalworking operations: (c) shearing
S MITHY&FORGING <ul><li>DIFFERENCES BETWEEN SMITHY AND FORGING </li></ul><ul><li>SMITHY – HAND OPERATED  -METAL IS DEFORME...
FORGING AND SMITHY <ul><li>SMITHY  PROCESS IS CARRIED BY HAND OPERATED TOOLS </li></ul><ul><li>FORGING IS CARRIED BY POWER...
Black smith tools <ul><li>Anvil </li></ul><ul><li>Swage block </li></ul><ul><li>Hammers </li></ul><ul><li>Tongs </li></ul>...
BLACK SMITH FORGE <ul><li>Black Smith Forge  </li></ul><ul><li>Heating of metal is done in hearth or furnance </li></ul><u...
WORKING OF FURNANCE <ul><li>Air at pressure  for combustion of fuel. </li></ul><ul><li>Centrifugal fan is driven by electr...
ANVIL <ul><li>It is made of solid wrought iron or cast steel. </li></ul><ul><li>It is a supporting the hot metal pieces to...
SWAGE BLOCK <ul><li>Solid or rectangular block  cast steel or forged steel. </li></ul><ul><li>Used for swaging, bending,fi...
TONGS <ul><li>Tongs are used for gripping and turning hot metal workpieces during forging. </li></ul><ul><li>Tong length :...
HAMMER  <ul><li>Hammer used by smith for striking and to give required shape to hot metal work piece. </li></ul><ul><li>Ha...
Ball Peen hammer
Straight Peen hammer
CROSS PIN HAMMER
Pneumatic hammer <ul><li>Small parts by hand hammers </li></ul><ul><li>Heavy machine parts require great degree of deforma...
Steam hammer
swages <ul><li>They are used in pairs. </li></ul><ul><li>Employed to reduce and finish the job to size or shape, round or ...
FULLERS <ul><li>It is set of two tools </li></ul><ul><li>Top tool is provided with handle and bottom has a square shank. F...
FORGING OPERATIONS <ul><li>Upsetting </li></ul><ul><li>Drawing </li></ul><ul><li>Cutting </li></ul><ul><li>Bending </li></...
UPSETTING OPERATION <ul><li>It is carried out to increase the thickness of bar and reduce its length. </li></ul><ul><li>Ex...
UPSETTING
DRAWING OPERATION <ul><li>To reduce thickness and increase its thickness. </li></ul><ul><li>It is carried out by working t...
PUNCHING <ul><li>The punch is driven part way through the workpiece with hammer blows. </li></ul><ul><li>The Work is turne...
BENDING OPERATION <ul><li>Bending is a common forging operation. </li></ul><ul><li>Simple process is  the bending a piece ...
Flatting and Setting Down <ul><li>Flattening leaves the a corrugated surface on  the job. </li></ul><ul><li>The marks of t...
FORGE WELDING <ul><li>Low carbon and wrought steel can satisfactorily forge welded. </li></ul><ul><li>Welding possible abo...
IMPORTANT QUESTIONS <ul><li>Define metal forming operations? </li></ul><ul><li>What is difference between Hot working and ...
IMPORTANT QUESTIONS <ul><li>What is the significance of hammers in forging? </li></ul><ul><li>Explain the major tools used...
Upcoming SlideShare
Loading in...5
×

Lecture 1 metal_forming

4,485

Published on

Published in: Business
2 Comments
2 Likes
Statistics
Notes
No Downloads
Views
Total Views
4,485
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
420
Comments
2
Likes
2
Embeds 0
No embeds

No notes for slide

Lecture 1 metal_forming

  1. 1. FUNDAMENTALS OF METAL FORMING <ul><li>Overview of Metal Forming </li></ul><ul><li>Material Behavior in Metal Forming </li></ul><ul><li>Temperature in Metal Forming. </li></ul><ul><li>Hot working and cold working operations. </li></ul><ul><li>Smithy, Smithy Tools, forging operations </li></ul>
  2. 2. Metal Forming <ul><li>Large group of manufacturing processes in which plastic deformation is used to change the shape of metal workpieces </li></ul><ul><li>The tool, usually called a die , applies stresses that exceed yield strength of metal </li></ul><ul><li>The metal takes a shape determined by the geometry of the die </li></ul>
  3. 3. Stresses in Metal Forming <ul><li>Stresses to plastically deform the metal are usually compressive </li></ul><ul><ul><li>Examples: rolling, forging, extrusion </li></ul></ul><ul><li>However, some forming processes </li></ul><ul><ul><li>Stretch the metal ( tensile stresses) </li></ul></ul><ul><ul><li>Others bend the metal ( tensile and compressive) </li></ul></ul><ul><ul><li>Still others apply shear stresses </li></ul></ul>
  4. 4. Material Properties in Metal Forming <ul><li>Desirable material properties: </li></ul><ul><ul><li>Low yield strength and high ductility </li></ul></ul><ul><li>These properties are affected by temperature : </li></ul><ul><ul><li>Ductility increases and yield strength decreases when work temperature is raised </li></ul></ul><ul><li>Other factors: </li></ul><ul><ul><li>Strain rate and friction </li></ul></ul>
  5. 5. Temperature in Metal Forming <ul><li>Any deformation operation can be accomplished with lower forces and power at elevated temperature </li></ul><ul><li>Three temperature ranges in metal forming: </li></ul><ul><ul><li>Cold working </li></ul></ul><ul><ul><li>Warm working </li></ul></ul><ul><ul><li>Hot working </li></ul></ul>
  6. 6. Hot Working <ul><li>Deformation at temperatures above recrystallization temperature </li></ul><ul><li>Recrystallization temperature = about one‑half of melting point on absolute scale </li></ul><ul><ul><li>In practice, hot working usually performed somewhat above 0.5 T m </li></ul></ul><ul><ul><li>Metal continues to soften as temperature increases above 0.5 T m , enhancing advantage of hot working above this level </li></ul></ul>
  7. 7. Why Hot Working? <ul><li>Capability for substantial plastic deformation of the metal ‑ far more than possible with cold working or warm working </li></ul><ul><li>Why? </li></ul><ul><ul><li>Strength coefficient is substantially less than at room temperature </li></ul></ul><ul><ul><li>Strain hardening exponent is zero (theoretically) </li></ul></ul><ul><ul><li>Ductility is significantly increased </li></ul></ul>
  8. 8. Warm Working <ul><li>Performed at temperatures above room temperature but below recrystallization temperature </li></ul><ul><li>Dividing line between cold working and warm working often expressed in terms of melting point: </li></ul><ul><ul><li>0.3 T m , where T m = melting point (absolute temperature) for metal </li></ul></ul>
  9. 9. Advantages of Warm Working <ul><li>Lower forces and power than in cold working </li></ul><ul><li>More intricate work geometries possible </li></ul><ul><li>Need for annealing may be reduced or eliminated </li></ul>
  10. 10. Advantages of Hot Working vs. Cold Working <ul><li>Workpart shape can be significantly altered </li></ul><ul><li>Lower forces and power required </li></ul><ul><li>Metals that usually fracture in cold working can be hot formed </li></ul><ul><li>Strength properties of product are generally isotropic </li></ul><ul><li>No strengthening of part occurs from work hardening </li></ul><ul><ul><li>Advantageous in cases when part is to be subsequently processed by cold forming </li></ul></ul>
  11. 11. Disadvantages of Hot Working <ul><li>Lower dimensional accuracy </li></ul><ul><li>Higher total energy required (due to the thermal energy to heat the workpiece) </li></ul><ul><li>Work surface oxidation (scale), poorer surface finish </li></ul><ul><li>Shorter tool life </li></ul>
  12. 12. Cold Working <ul><li>Performed at room temperature or slightly above </li></ul><ul><li>Many cold forming processes are important mass production operations </li></ul><ul><li>Minimum or no machining usually required </li></ul><ul><ul><li>These operations are near net shape or net shape processes </li></ul></ul>
  13. 13. HOT WORKING OPERATIONS <ul><li>FORGING </li></ul><ul><li>ROLLING </li></ul><ul><li>WELDING </li></ul><ul><li>EXTRUSION </li></ul><ul><li>SPINNING </li></ul><ul><li>HOT PIERCING AND ROLLING </li></ul>
  14. 14. COLD WORKING OPERATIONS <ul><li>COLD ROLLING </li></ul><ul><li>EXTRUSION </li></ul><ul><li>PRESSING </li></ul><ul><li>DEEP DRAWING </li></ul><ul><li>SQUEEZING </li></ul><ul><li>BENDING </li></ul><ul><li>SHEARING </li></ul>
  15. 15. Figure 18.2 – Basic bulk deformation processes: (a) rolling
  16. 16. Figure 18.2 – Basic bulk deformation processes: (b) forging
  17. 17. Figure 18.2 – Basic bulk deformation processes: (c) extrusion
  18. 18. Figure 18.2 – Basic bulk deformation processes: (d) drawing
  19. 19. Sheet Metalworking <ul><li>Forming and related operations performed on metal sheets, strips, and coils </li></ul><ul><li>High surface area‑to‑volume ratio of starting metal, which distinguishes these from bulk deformation </li></ul><ul><li>Often called pressworking because presses perform these operations </li></ul><ul><ul><li>Parts are called stampings </li></ul></ul><ul><ul><li>Usual tooling: punch and die </li></ul></ul>
  20. 20. Figure 18.3 ‑ Basic sheet metalworking operations: (a) bending
  21. 21. Figure 18.3 ‑ Basic sheet metalworking operations: (b) drawing
  22. 22. Figure 18.3 ‑ Basic sheet metalworking operations: (c) shearing
  23. 23. S MITHY&FORGING <ul><li>DIFFERENCES BETWEEN SMITHY AND FORGING </li></ul><ul><li>SMITHY – HAND OPERATED -METAL IS DEFORMED INTO THE DESIRED SHAPE BY HAMMERING, PRESSING AND BENDING USING HAND OPERATED TOOLS. </li></ul><ul><li>FORGING– MACHINE OPERATED – METAL IS DEFORMED INTO THE DESIRED SHAPE BY HAMMERING , PRESSING AND BENDING USING POWER OPERATED MACHINES. </li></ul>
  24. 24. FORGING AND SMITHY <ul><li>SMITHY PROCESS IS CARRIED BY HAND OPERATED TOOLS </li></ul><ul><li>FORGING IS CARRIED BY POWER OPERATED TOOLS. </li></ul><ul><li>SMITHY IS CARRIED FOR SMALL JOBS AND FORGING IS FOR HEAVY WORK AND MASS PRODUCTION </li></ul><ul><li>FOR FORGING, SHAPES ARE ALSO PRE DEFINED IN FORM OF DIES, WHERE AS FOR SMITHY, REQUISTE SHAPES ARE GENERATED BY THE REPETITVE PROCESS REPETITIVE USE OF HAND TOOLS. </li></ul>
  25. 25. Black smith tools <ul><li>Anvil </li></ul><ul><li>Swage block </li></ul><ul><li>Hammers </li></ul><ul><li>Tongs </li></ul><ul><li>Chisels </li></ul><ul><li>Swages </li></ul><ul><li>Fullers </li></ul><ul><li>Flatters </li></ul><ul><li>Punches </li></ul>
  26. 26. BLACK SMITH FORGE <ul><li>Black Smith Forge </li></ul><ul><li>Heating of metal is done in hearth or furnance </li></ul><ul><li>It is shallow dish or tray of Mild steel with lining of fire clay or refractory material to withstand heat during combustion of fuel. </li></ul><ul><li>Open hearth and closed hearth (open fire &stock fire) </li></ul><ul><li>Smoke or gas are escaped through hood or chimney </li></ul>
  27. 27. WORKING OF FURNANCE <ul><li>Air at pressure for combustion of fuel. </li></ul><ul><li>Centrifugal fan is driven by electrical motor. </li></ul><ul><li>It draws air from atmiosphere and delivers at high pressure to furnance </li></ul><ul><li>It is mainly used for maintaining combustion of fuel in furnance,. </li></ul>Standard coal forge
  28. 28. ANVIL <ul><li>It is made of solid wrought iron or cast steel. </li></ul><ul><li>It is a supporting the hot metal pieces to be forged. </li></ul><ul><li>Tools like swages or fullers are inserted into the holes </li></ul><ul><li>Bick or horn of the anvil is used for bending </li></ul><ul><li>Forging operations are carried out on the face of the anvil </li></ul>
  29. 29. SWAGE BLOCK <ul><li>Solid or rectangular block cast steel or forged steel. </li></ul><ul><li>Used for swaging, bending,finishing various workpieces. </li></ul><ul><li>Workpiece is given rough shape on anvil , reheated placed in a similar shaped recess in the side of the swage block. </li></ul>
  30. 30. TONGS <ul><li>Tongs are used for gripping and turning hot metal workpieces during forging. </li></ul><ul><li>Tong length : 475 – 600 mm length </li></ul><ul><li>Bit length - 75-120 mm </li></ul><ul><li>Material : 0.4% carbon. </li></ul><ul><li>Types: Pick up tong, square tong, round tong flat tong, 16 types of tongs used to accomdate different sized and shaped workpieces. </li></ul>
  31. 31. HAMMER <ul><li>Hammer used by smith for striking and to give required shape to hot metal work piece. </li></ul><ul><li>Hand hammer – small and light components. </li></ul><ul><li>Types : </li></ul><ul><li>Ball pein hand hammer : Face : general striking, ball pien is used for riveting or burring over work. </li></ul><ul><li>Cross pein hammer: cross : hammmering streching, bending into inside shape of component . </li></ul><ul><li>Straight peen hammer: : It is used for stretching the metal </li></ul><ul><li>Sledge hammer.: Heavier hammer, used for flattening. </li></ul>
  32. 32. Ball Peen hammer
  33. 33. Straight Peen hammer
  34. 34. CROSS PIN HAMMER
  35. 35. Pneumatic hammer <ul><li>Small parts by hand hammers </li></ul><ul><li>Heavy machine parts require great degree of deformation </li></ul><ul><li>Hand forging lengthy process </li></ul><ul><li>Machines which works on the principle of repeated blows - power or forging hammers. </li></ul><ul><li>Spring Hammer </li></ul><ul><li>Air Hammer </li></ul><ul><li>Steam hammer </li></ul><ul><li>Drop hammer </li></ul>
  36. 36. Steam hammer
  37. 37. swages <ul><li>They are used in pairs. </li></ul><ul><li>Employed to reduce and finish the job to size or shape, round or heaxgonal. </li></ul><ul><li>Small jobs , swages are used, large work, swage blocks are used. </li></ul><ul><li>During swaging, hot metal is rotated between the swages . </li></ul>
  38. 38. FULLERS <ul><li>It is set of two tools </li></ul><ul><li>Top tool is provided with handle and bottom has a square shank. Fits into square hole. </li></ul><ul><li>Fullers are used to form grooves, stretch or draw the metal and reduce the thickness of the workpiece . </li></ul>
  39. 39. FORGING OPERATIONS <ul><li>Upsetting </li></ul><ul><li>Drawing </li></ul><ul><li>Cutting </li></ul><ul><li>Bending </li></ul><ul><li>Punching </li></ul><ul><li>Welding </li></ul><ul><li>Setting down </li></ul>
  40. 40. UPSETTING OPERATION <ul><li>It is carried out to increase the thickness of bar and reduce its length. </li></ul><ul><li>Ex: Bolt Head </li></ul><ul><li>Blow of the hammer must be in line with the bar to prvent bending of the bar. </li></ul><ul><li>Hot bar must be in line with the bar to prevent bending of the bar. </li></ul>
  41. 41. UPSETTING
  42. 42. DRAWING OPERATION <ul><li>To reduce thickness and increase its thickness. </li></ul><ul><li>It is carried out by working the metal over the horn of the anvil then hammering on the anvil face. </li></ul><ul><li>For heavy work, fullers are used </li></ul>
  43. 43. PUNCHING <ul><li>The punch is driven part way through the workpiece with hammer blows. </li></ul><ul><li>The Work is turned over and the hole is completed from the other side. </li></ul><ul><li>PUNCHING OPERATION </li></ul>
  44. 44. BENDING OPERATION <ul><li>Bending is a common forging operation. </li></ul><ul><li>Simple process is the bending a piece of metal, is to support it on the anvil/Die and to strike its free end with a hammer. </li></ul><ul><li>When bent , workpiece thins out round bend causing weakness. </li></ul>
  45. 45. Flatting and Setting Down <ul><li>Flattening leaves the a corrugated surface on the job. </li></ul><ul><li>The marks of the hammer remains on the surface , and the removal of its is called flatter. </li></ul><ul><li>Flatting and setting down used to finish off to a good smooth surface. </li></ul><ul><li>Flatter is used for smoothening flat surfaces, </li></ul><ul><li>Set hammer is used in restricted areas, such as corners and bends. </li></ul>
  46. 46. FORGE WELDING <ul><li>Low carbon and wrought steel can satisfactorily forge welded. </li></ul><ul><li>Welding possible above 30mm thickness. </li></ul><ul><li>Parts are heated to stage of plastic and placed ebd to end and hammered manually or by power hammer </li></ul>
  47. 47. IMPORTANT QUESTIONS <ul><li>Define metal forming operations? </li></ul><ul><li>What is difference between Hot working and cold working operations? </li></ul><ul><li>Name the various processes of metal forming operations. </li></ul><ul><li>What is the difference between smithy and forging? </li></ul>
  48. 48. IMPORTANT QUESTIONS <ul><li>What is the significance of hammers in forging? </li></ul><ul><li>Explain the major tools used in smithy? </li></ul><ul><li>What is the application difference between fuller and swage? </li></ul><ul><li>What are the major forging operations? </li></ul><ul><li>What is the difference between Upsetting and drawing operations ? </li></ul>
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×