(INDIRA) Call Girl Meerut Call Now 8617697112 Meerut Escorts 24x7
Rolling
1.
2. Theory of RollingTheory of Rolling
Rolling is a metallurgical process used toRolling is a metallurgical process used to
shape the metal to desired shape.shape the metal to desired shape.
- Here in VSP the application is for HotHere in VSP the application is for Hot
Rolling of Steel only.Rolling of Steel only.
- Rolling is very important process amongRolling is very important process among
the various methods as 90% of the metalthe various methods as 90% of the metal
products used are Rolled products only.products used are Rolled products only.
3. Theory of RollingTheory of Rolling
- Hot Rolling of metal involves heating ofHot Rolling of metal involves heating of
the metal above the recrystallizationthe metal above the recrystallization
temperature and is performed between thetemperature and is performed between the
temperatures of 1200 ‘C to 900 ‘ C.temperatures of 1200 ‘C to 900 ‘ C.
- Heating is done in the Furnaces.Heating is done in the Furnaces.
- Hot Rolling is done in the 2-High RollHot Rolling is done in the 2-High Roll
stands.stands.
4. Theory of RollingTheory of Rolling
Angle of BiteAngle of Bite
Top Roll
Bottom Roll
Input
H0
Output
H1
5. Theory of RollingTheory of Rolling
Angle of bite is 25-30 Degrees in case ofAngle of bite is 25-30 Degrees in case of
Continuos Mills and a max of 20 DegreesContinuos Mills and a max of 20 Degrees
in case of Cross-country Mills.in case of Cross-country Mills.
The picture also indicates that the moreThe picture also indicates that the more
the Roll Dia the more is the spread.the Roll Dia the more is the spread.
There is also a condition of Forward &There is also a condition of Forward &
Backward slip which effects the speed ofBackward slip which effects the speed of
the material to some extent.the material to some extent.
6. Theory of RollingTheory of Rolling
The important point considered for RollingThe important point considered for Rolling
process isprocess is
- The Volume is always constant- The Volume is always constant
i.e the input volume is equal to the outputi.e the input volume is equal to the output
volume.volume.
B0 X H0 X L0 = B1 X H1 X L1B0 X H0 X L0 = B1 X H1 X L1
or (B0/B1)x(H0/H1)x(L0/L1) = 1or (B0/B1)x(H0/H1)x(L0/L1) = 1
wherein B0/B1 is Spreadwherein B0/B1 is Spread
H0/H1 is DraftH0/H1 is Draft
L0/L1 is elongationL0/L1 is elongation
7. Rolling Process in VSPRolling Process in VSP
STEEL MELTING
SHOP
Bloom
320X250
Bloom
250X250
LMMM MMSM
BRM WRM
PRODUCTS- BARS & ROUNDS
Light STRUCTURALS
PRODUCTS- ROUNDS
and Medium
STRUCTURALS
8. Types of MillsTypes of Mills
Cross Country millsCross Country mills
- Low Production- Low Production
- More Manual- More Manual
involvementinvolvement
- 2-high or 3-high- 2-high or 3-high
RollingRolling
- High Section Change- High Section Change
timetime
Continuous MillsContinuous Mills
- High Production- High Production
- More Rolls & Guides.- More Rolls & Guides.
- 2-high Rolling- 2-high Rolling
- Less Manual- Less Manual
interventionintervention
- easy section changes- easy section changes
9. Theory of Rolling-Roll Pass designTheory of Rolling-Roll Pass design
It is a Rolling Technology which deals withIt is a Rolling Technology which deals with
production of desired shape withinproduction of desired shape within
permissible deviations with the requiredpermissible deviations with the required
surface finish free from any surfacesurface finish free from any surface
defects.It also has to ensure optimumdefects.It also has to ensure optimum
utilization of mill equipment,high rollingutilization of mill equipment,high rolling
rate and safe working conditions ofrate and safe working conditions of
operators.operators.
10. Theory of Rolling- Roll pass DesignTheory of Rolling- Roll pass Design
The following factors are considered forThe following factors are considered for
development of Roll pass design:-development of Roll pass design:-
Power Availability.Power Availability.
No. of Stands.No. of Stands.
Roll barrel length , roll material etcRoll barrel length , roll material etc
Input material.Input material.
11. Theory of Rolling- Roll pass DesignTheory of Rolling- Roll pass Design
Factors influencing the spread are:Factors influencing the spread are:
- Reduction in height or the Draft.- Reduction in height or the Draft.
- Roll Diameter.- Roll Diameter.
- Rolling Temperature.- Rolling Temperature.
- Friction between rolls and the rolled- Friction between rolls and the rolled
materialmaterial
- Steel Composition.- Steel Composition.
12. Theory of Rolling- Roll pass DesignTheory of Rolling- Roll pass Design
The degree of spread of a steel dependsThe degree of spread of a steel depends
on the steel composition:-on the steel composition:-
- Carbon:Increase in Carbon increases- Carbon:Increase in Carbon increases
spreadspread
- Chromium: same as above.- Chromium: same as above.
- Nickel : inversely proportional to spread.- Nickel : inversely proportional to spread.
- Manganese: Directly proportional to- Manganese: Directly proportional to
spread.spread.
13. TTheory of Rolling- Roll passDesignheory of Rolling- Roll passDesign
The Various Shapes of passes for roundThe Various Shapes of passes for round
rolling:rolling:
BOX Diamond
Square
Oval
Round
14. TTheory of Rolling- Roll passDesignheory of Rolling- Roll passDesign
The different Rolling Sequences used in RollThe different Rolling Sequences used in Roll
pass design as per requirement are:-pass design as per requirement are:-
- Box – Oval – Round.- Box – Oval – Round.
- Box – Diamond – Square.- Box – Diamond – Square.
- Square – Oval – Round.- Square – Oval – Round.
- Box – Box - Box- Box – Box - Box
- Butterfly pass is used in Angle Rolling.- Butterfly pass is used in Angle Rolling.
- Edger pass is used in Flat Rolling.- Edger pass is used in Flat Rolling.
- Closed passes are used in Chanel & Beam- Closed passes are used in Chanel & Beam
RollingRolling
15. Theory of Rolling-Rolling PracticeTheory of Rolling-Rolling Practice
The most important points to noted forThe most important points to noted for
efficient Rolling practice are:-efficient Rolling practice are:-
-Proper Mill Settings-Proper Mill Settings
-Roll Pass & Guide alignment.-Roll Pass & Guide alignment.
- Roll wear compensation.- Roll wear compensation.
- Timely Pass Changes.- Timely Pass Changes.
- Material Temperature.- Material Temperature.
- Speed adjustments.- Speed adjustments.
17. TOTAL ROLLS REQUIRED BY VSP
TONNAGE : 1200-1500 T/Year
No of rolls/year : 400-500
VSP : ROLLS REQUIREMENT
TYPES OF ROLLS USED IN VSP
CAST IRON
CAST STEEL
FORGED
18. Strand
No
Roll Size (mm)
(Dia x B.L)
Roll Material
BILLET MILL – WORK ROLLSBILLET MILL – WORK ROLLS
1& 2 850 x 1200 AFS 40-45 SHC
UTS 85-100 Kgf/mm2
3 730 x 1000 AFS 40-45 SHC
UTS 85-100 Kgf/mm2
4 730 x 1000 SGCI 50-55 SHC
5 650 x 1000 SGCI 50-55 SHC
6 650 x 1000 SGCI 55-60 SHC
7 630 x 1000 SGCI 55-60 SHC
TYPE OF ROLLS USED
19. Strand No Roll Size (mm)
(Dia x B.L)
Roll Material
WIRE ROD MILL- WORK ROLLSWIRE ROD MILL- WORK ROLLS
H1& H2 610 x 1000 SGCI 48-53 SHC
H3 TO H5 610 x 1000 SGCI 52-57 SHC
H6 490 x 960 SGCI 52-57 SHC
H7 490 x 960 SGCI 52-57 SHC
H8 TO H10 480 x 840 SGCI 68-72 SHC
H11 TOH13 375 x 740 SG(AC) 70-75 SHC
TYPE OF ROLLS USED
20. Strand No Roll Size (mm)
(Dia x B.L)
Roll Material
MMSM- WORK ROLLS -1MMSM- WORK ROLLS -1
1 TO 10
(Rounds & squares)
680 x 1000 ACS 40-45 SHC &
UTS 740-960 N/mm2
1 TO 14
(Structurals)
660 x 825 ACS 40-45 SHC &
UTS 740-960 N/mm2
11 TO 14
(Rounds & squares)
680 x 1000 SGCI 50-55 SHC
15 TO 20
(Rounds, squares,
flats & beams)
555 x 630 SGCI 58-63 SHC
15 TO 20
(Angles & channels)
555 to 670 SGCI 58-63 SHC
375 x 740 SG(AC) 70-75 SHC
TYPE OF ROLLS USED
21. Strand No Roll Size (mm)
(Dia x B.L)
Roll Material
MMSM- WORK ROLLS-2MMSM- WORK ROLLS-2
11 & 13 U-H 1070 x 180 SGCI 58-63 SHC
15,16,18 &20
U-H
900 X 180 SGCI 58-63 SHC
11 & 13 U-V 710 x 170 HICRCI 63-68 SHC
15,16,18 & 20
U-V
600 x 170 HICRCI 63-68 SHC
TYPE OF ROLLS USED
22. Strand No Roll Size (mm)
(Dia x B.L)
Roll Material
BAR MILL- WORK ROLLS -1BAR MILL- WORK ROLLS -1
H1 610 x 1244 AFS 40-45 SHC
UTS 85-100
Kgf/mm2
H2 TO H4 610 X 1244 ACS 40-45 SHC &
UTS 85-100 N/mm2
H5 TO H8 460 x 1084 SGCI 50-55 SHC
H6 TO H8
(angles&channels)
430 TO 495 x
850
SGCI 50-55 SHC
H9 TO H 18 380 TO 495 x
850
SGCI 50-55 SHC
TYPE OF ROLLS USED
23. Strand No Roll Size (mm)
(Dia x B.L)
Roll Material
BAR MILL- WORK ROLLS -2BAR MILL- WORK ROLLS -2
V11 & V16 360 x 600 SGCI 58-63 SHC
V 19 –V21 360 X 600 SG(AC) 70-755 SHC
H-20 –H22
(round upto 20mm)
360 x 600 DPCI 72-77 SHC
H 22(all rebars) 360 x 600 SGCI 68-73 SHC
H 20 – H22
(round TO 36 mm)
360 x 600 SG(AC)68-73 SHC
H 20 – H22
(angles)
340 TO 450 x
600
SGCI 56-60 SHC
H20 TO H 22 340 TO 450 x
600
SGCI 56-60 SHC
TYPE OF ROLLS USED
