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Rolling Process

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Roll Deformation

Courtesy: www.jfe-21st-cf.or.jp

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Types of Rolling mills

Schematic illustration of various roll arrangements:

(a) two high; (b) three high; (c) four high; (d) cluster;

(e) tandem rolling with three stands; (f) planetary

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Shape rolling

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Rolling Forming Process

Courtesy: www.commercialroll.com

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Courtesy: www.profilemetal-ray.com

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Courtesy: www.thefabricator.com

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Rolling of Threads

Thread-rolling processes: (a) flat dies and (b) two roller

dies. These processes are used extensively in

making threaded fasteners at high rates of

production.

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Thread Rolling Process

Courtesy: www.rpi.edu

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Rolled vs Machined Threads

(a) Schematic illustration of machined or rolled threads.

(b) Grain-flow lines in machined and rolled threads. Unlikemachined threads, which are cut through the grains of

the metal, rolled threads follow the grains and are

stronger, because of the cold working involved.

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Mannesman’s Process of Seam less tube

manufacturing by Rolling

Cavity formation by secondary tensile stresses in a solid round bar

and its use in the rotary-tube-piercing process. This procedure

uses the principle of the Mannesmann mill for seamless tube

making. The mandrel is held in place by the long rod, although

techniques have been developed in which the mandrel remains inplace without the rod.

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Tube Rolling (Piercing)

Courtesy: www.usstubular.comhttp://www.youtube.com/watch?v=a947wTtY5xc&feature=related

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Ring Rolling

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Defects in Rolling processes

Edge Cracking;

Due to excessive thickness redn.

Alligatoring:

Due to Ratio of slab thickness

to length of contact 1.4 to 1.7

Folds: Due to low reduction per pass

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Forging Process

Courtesy: www.doitpoms.ac.uk

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Forging Process


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Forging Process


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Impression Die Forging Process


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Swaging Process

Courtesy: www.torrington-machinery.com

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Coining

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Balls for bearings

Production of steel balls

by upsetting of acylindrical blank.

Note the formation of

flash. The balls are

subsequently groundand polished for use as

ball bearings and in

other mechanical

components.

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Upsetting

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Equipment for Forging work

(a) For few small object (Black Smithy) –

Hammers & Anvil

(b) For lot production of medium size

objects (drop forging)

(i) Mechanical power hammer (ii) Pneumatic power hammer

(ii i)Steam powered hammer

(c) For lot production of large jobs

(pressing)

(i) Hydraulic Press

(ii) Mechanical Press

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Schematic i llustration of various types of presses used in

metalworking.

The choice of the press is an important factors in the overall

operation.

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Forging Defects

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Effect of fi llet radius on defect formation in forgings. Small filletscause the defects.

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Extrusion Process


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Extrusion Process


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Extrusion Process


http://upload.wikimedia.org/wikipedia/commons/e/ef/Extruded_aluminium_section_x3.jpg

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Extrusion Process

Courtesy: www.roymech.co.uk

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Hydrostatic Extrusion Process

Courtesy: www.roymech.co.uk

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Drawing Process


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Drawing Process


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Drawing Process


How passes are decided (3 mm to 0.5 mm)

Maximum Possible Reduction = 0.632

3 mm to 1.9 mm (330 N)1.9 mm to 1.2 mm (132 N)

1.2 mm to 0.76 mm (53 N)

0.76 mm to 0.5 mm (21 N)

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Metal Forming Processes

Bulk Forming Processes Sheetmetal Forming Processes

Rolling Processes Shearing Processes

Forging Processes Bending Processes

Extrusion Processes Drawing Processes

Drawing Processes

Documents

me120_lect10