copyright prentice-hall chapter 13 rolling of metals
TRANSCRIPT
![Page 1: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/1.jpg)
Copyright Prentice-Hall
Chapter 13Rolling of Metals
![Page 2: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/2.jpg)
Flat-Rolling and Shape-Rolling
Processes
Schematic outline of various flat-rolling and shape-rolling processes. Source: After the American Iron and Steel Institute.
![Page 3: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/3.jpg)
Flat-Rolling Process
(a) Schematic illustration of the flat-rolling process. (b) Friction forces acting on strip surfaces. (c) Roll force, F, and the torque, T, acting on the rolls. The width of the strip, w, usually increases during rolling.
![Page 4: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/4.jpg)
Roll Arrangements
Schematic illustration of various roll arrangements: (a) four-high rolling mill showing various features. The stiffness of the housing, the rolls, and the roll bearings are all important in controlling and maintaining the thickness of the rolled strip; (b) two-hill mill; (c) three-high mill; and (d) cluster (or Sendzimir) mill.
![Page 5: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/5.jpg)
Bending of Rolls
(a) Bending of straight cylindrical rolls caused by roll forces. (b) Bending of rolls ground with camber, producing a strip with uniform thickness through the strip width. Deflections have been exaggerated for clarity.
![Page 6: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/6.jpg)
Spreading in Flat Rolling
Increase in strip width (spreading) in flat rolling. Note that similar spreading can be observed when dough is rolled with a rolling pin.
![Page 7: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/7.jpg)
Effects of Hot Rolling
Changes in the grain structure of cast or of large-grain wrought metals during hot rolling. Hot rolling is an effective way to reduce grain size in metals for improved strength and ductility. Cast structures of ingots or continuous castings are converted to a wrought structure by hot working.
![Page 8: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/8.jpg)
Roller Leveling
(a) A method of roller leveling to flatten rolled sheets. (b) Roller leveling to straighten drawn bars.
![Page 9: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/9.jpg)
Defects in Flat Rolling
Schematic illustration of typical defects in flat rolling: (a) wavy edges; (b) zipper cracks in the center of the strip; (c) edge cracks; and (d) alligatoring.
![Page 10: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/10.jpg)
Residual Stresses Developed in Rolling
(a) Residual stresses developed in rolling with small-diameter rolls or at small reductions in thickness per pass. (b) Residual stresses developed in rolling with large-diameter rolls or at high reductions per pass. Note the reversal of the residual stress patterns.
![Page 11: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/11.jpg)
Rolling Mill
A general view of a rolling mill. Source: Courtesy of Ispat Inland.
![Page 12: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/12.jpg)
Tandem-Rolling
An example of a tandem-rolling operation.
![Page 13: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/13.jpg)
Shape Rolling of an H-section part
Steps in the shape rolling of an H-section part. Various other structural sections, such as channels and I-beams, also are rolled by this kind of process.
![Page 14: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/14.jpg)
Roll-Forging
Two examples of the roll-forging operation, also known as cross-rolling. Tapered leaf springs and knives can be made by this process. Source: After J. Holub.
![Page 15: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/15.jpg)
Production of Steel Balls
(a) Production of steel balls by the skew-rolling process. (b) Production of steel balls by upsetting a cylindrical blank. Note the formation of flash. The balls made by these processes subsequently are ground and polished for use in ball bearings.
![Page 16: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/16.jpg)
Ring-Rolling
(a) Schematic illustration of a ring-rolling operation. Thickness reduction results in an increase in the part diameter. (b-d) Examples of cross-sections that can be formed by ring-rolling.
![Page 17: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/17.jpg)
Thread-Rolling Processes
Thread-rolling processes: (a) and (c) reciprocating flat dies; (b) two-roller dies. (d) Threaded fasteners, such as bolts, are made economically by these processes at high rates of production. Source: Courtesy of Central Rolled Thread Die Co.
![Page 18: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/18.jpg)
Machined and Rolled Threads
(a) Features of a machined or rolled thread. Grain flow in (b) machined and (c) rolled threads. Unlike machining, which cuts through the grains of the metal, the rolling of threads imparts improved strength because of cold working and favorable grain flow.
![Page 19: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/19.jpg)
Cavity Formation in Bar
Cavity formation in a solid, round bar and its utilization in the rotary tube-piercing process for making seamless pipe and tubing. (see also Fig. 2.9.)
![Page 20: Copyright Prentice-Hall Chapter 13 Rolling of Metals](https://reader035.vdocuments.mx/reader035/viewer/2022081508/56649f285503460f94c412cf/html5/thumbnails/20.jpg)
Various Tube-Rolling Processes
Schematic illustration of various tube-rolling processes: (a) with a fixed mandrel; (b) with a floating mandrel; (c) without a mandrel; and (d) pilger rolling over a mandrel and a pair of shaped rolls. Tube diameters and thicknesses also can be changed by other processes, such as drawing, extrusion, and spinning.