1. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Continuous Cross Section Rolling Extrusion Drawing

2. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Rolling ( 압연 ) Metal stock is passed through a pair of rolls to reduce thickness. Hot rolling ( 열간압연 ) > recrystallization temperature > Cold rolling ( 냉간압연 ) (Roll bending) (Roll forming) Flat rolling Ring rolling Structural shape rolling http://www.youtube.com/watch?v=6xnKmt_gsLs&p=9B6D9EAE75875D9Dhttp://www.youtube.com/watch?v=6xnKmt_gsLs&p=9B6D9EAE75875D9D Rolling 3m

3. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Flat Rolling ( 평판 압연 ) Rectangular cross-section (sheet, plate) Force: F ≈ σ y lw Draft: t 0 - t f < μ 2 R t0t0 tftf R w l F

4. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Ex) Flat Rolling Force Power Ductile plate (width: 0.1 m, thickness: 10 mm, strength: 400 MPa) is rolled by flat rollers (radius: 0.1 m). The friction coefficient of roller and plate is 0.2 and production rate is 1 m/s. How many times should the plate pass the roller to get 5 mm thickness plate? Please predict approximate rolling Force (kN) and Power (kW).

5. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Ring rolling ( 링압연 ) Driven and idle roll presses the ring to decrease thickness and increase diameter. Driven roll Idler roll Side roll http://www.youtube.com/watch?v=GDyWyDP3cvshttp://www.youtube.com/watch?v=GDyWyDP3cvs Ring rolling

6. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Structural shape rolling ( 형압연 ) Structural shape rolling uses profile rolling techniques where the workpiece is passed through a series of rollers that match the workpieces' cross-section.

7. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Thread rolling ( 나사 전조 ) Bolt: http://www.youtube.com/watch?v=7ORomNNCSUQ&p=9B6D9EAE75875D9D Bolt Nut 5mhttp://www.youtube.com/watch?v=7ORomNNCSUQ&p=9B6D9EAE75875D9D www.horstengineering.com Threads are formed by pressing a blank with the former(shaped die). Thread Rolling Die Blank

8. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Extrusion ( 압출 ) Hot extrusion profiles of steel A round billet is placed in a chamber and forced through a die opening by a ram. It creates complex fixed cross-sectionals. Pressure: p≈σ y (0.8+1.4ln(A o /A f )) Die Ram F Billet Container http://www.youtube.com/watch?v=7qiDJ5U4uRchttp://www.youtube.com/watch?v=7qiDJ5U4uRc Extrusion 1m AfAf AoAo

9. © 2012 Su-Jin Kim GNU Bulk Deforming Manufacturing Processes Drawing ( 인발 ) Reduce the cross-section of a road, wire or tube by pulling it through a drawing die Lubrication is essential for good surface finish and long die life Die A0A0 AfAf F