Rolling Mill Configuration

1. AARTI STEEL - TRAINING
Abhishek Singh

2. Agenda
• Overview
• Basics of grinding wheel
• LDCO wheel manufacturing
& it’s application
• Importance of safety

3. 3 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

4. 4 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Rough Grinding
 Bench/pedestal
 Swing frame
 Steel conditioning
 Cutting off
 Portable (DCD)
 Portable (cut-off)
Precision Grinding
• Cylindrical Centerless
• Internal Surface
• Tool/cutter Form
• Disc Honing
• Crankshaft Camshaft
• Roll Gear
Ultra Precision Grinding
• Silicon wafers in electronics
• Slicing of R/W heads
• Edging of hard discs
• Syringe/Needle
• Super Finishing

5. 5 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

6. 6 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Grinding Wheel constituents
• Thousands of sharp Abrasive grains
• Bond to hold the grains firmly together
• Structure or grain spacing
Abrasive
Structure
Pores
Bond
Grade
Abrasive
Grain

7. 7 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Abrasives
A, 32A, 38A, 86A, 37C, 39C,
SG, TG, NQ, NQG, NQK, NPG,
NZ,ZF,ZS
Grit Size
Coarse Med. Fine Very
Fine
10 30 70 220
12 36 80 240
14 40 90 280
16 46 100 320
20 54 120 400
24 60 150 500
180 600
Structure
The structure
number of a wheel
refers to the
relative spacing of
the grains of
abrasive; the
larger the number,
the wider the
grain spacing.
Bond Type
V = Vitrified
B = Resinoid
R = Rubber
Manufacturer Symbol
Letter or numeral or both to
designate a variation or
modification of bond or
other characteristic of the
wheel. Typical symbols are
“P”, “G”, “BE”.
Grade
Soft Med Hard
A E I M Q V
B F J N R W
C G K O S X
D H L P T Y
U Z
5ZFQ16-4SBF2

8. 8 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
• Abrasives are very hard materials … that can be used for removing / shaping / finishing other
( relatively ) softer materials … by a grinding or abrading action.
• Conventional abrasives are of 2 types
• Aluminum Oxide (AlO)  Used to grind ferrous material/alloys
• Silicon Carbide (SiC) Used to grind non-ferrous material/alloys
Brown White Purple
Monocryst. Pink Ceramic Black
SiC
Green
SiC
Zirconia
Alumina Norzon

9. 9 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
1. GRIT SIZE
Grit Size is the grain size measured in terms of the approximately number of
openings per linear inch in the final screen used to size the grain.
2. GRADE
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
SOFT MEDIUM HARD
Cuts cooler
Cuts faster
Wears less
Keeps its shape
MORE BOND

10. 10 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
3. STRUCTURE
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
More space between grains & less abrasive in the wheel
CLOSED MEDIUM OPEN
4. BOND
VITRIFIED (Glass)
• Rigid
• Low Std. speeds.
• Hold Form.
• Fragile
• Fired - 900 - 1200 °C
Lower Impact Resistivity.
No Shelf Life.
ORGANIC (Resin, Rubber, Shellac)
• Flexible
• High Speed
• Better Finish
• Impact Resistant
• Cured - 200 °C
– Reinforceable
Lower Heat Resistance
Less Chemically durable
Shelf Life – 1-2 year

11. 11
Hardness of Selected Materials Including Abrasives
Hardness, HK (kg/mm2)
7000
4700
2750
2500
2400
2100
1900
1800
1500
1360
1150
825
820
550
500
370
185
135
0 1000 2000 3000 4000 5000 6000 7000 8000
Diamond
CBN
Boron carbide
Vanadium carbide
Silicon carbide
Aluminum oxide
Tungsten carbide
Silicon nitride
Zirconium oxide
Garnet
Silicon
Hardened steel
Quartz
Ferrite
Glass
Magnesia
Soft steel
Calcite
Material
Conventional
Hardness is the property of a material
that enables it to resist plastic
deformation, penetration, indentation
and scratches.
Friability Ability of an abrasive to
fracture and expose new sharp points
within the same grain. Friable abrasives
fracture readily, maintain sharpness and
reduce chance of thermal metal damage.
Super-abrasive

12. 12 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
• LDCOW wheel made at the following locations :
• North America  Worcester Plant
• Europe  AMI Italy

13. 13 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

14. 14 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

15. 15 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Pre dressing inspection
• Sand Blast Penetration (Assures specification &
Hardness)
• E-Mod (Assures wheel integrity & hardness)
• Density (Assures specification)
Final Inspection
• Speed testing (Assures wheel integrity)
• Imbalance (Assures proper use)
• Dimensional testing

16. 16 STEEL INDUSTRY - TRAINING HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Square Bar
Pipe
Round Bar
shaft Bearing Military Pipe Sheet metal Slab

17. 17 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

18. 18 STEEL INDUSTRY - TRAINING HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Primary
NZ Premium Zirconia
ZF Sharpened Zirconia Aluminium
Q Doped Aluminium Oxide
O Sintered Bauxite
K Premium aluminium oxide
Conventional
A Fused aluminium oxide
U Blocky aluminium oxide
D Semi-friable aluminium oxide
R Friable pink aluminium oxide
C Black Silicon Oxide
TOROS
A Aluminium Oxide (including SG,XG & NQ)
C Silicon Carbide
ZF Zirconia (Zf & NZ)
AZ Aluminium Oxide & Zirconia Blend
Abrasive Nomenclature

19. 19 STEEL INDUSTRY - TRAINING HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

20. 20 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
The diagram below shows an example of a traverse cutting-off application with main operating parameters highlighted.
PROFILE CHARACTERISTICS
Wheel profile is influenced by internal fiberglass, layer & working par.
• Square/Light Convex: most common for correct application
• Concave: most common when mild specifications are used with light pressure on the work-piece.
Helps to maintain straight cutting.
• Pointed: wheel is too hard cutting or feed rate is too slow

21. 21 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Cross section Size range cutting speed (m/s) Feed rate (mm/s) (range)
Round 40-50 90 -95 22-20
Round 50-60 90 -95 20-18
Round 60-70 90 -95 18-17
Round 70-80 90 -95 17-16
Round 80-90 90 -95 16-14
Round 90-110 90 -95 14-12
Round 110-130 90 -95 12-10
Round 130-150 90 -95 10-8
Square 40-50 90 -95 20-18
Square 50-60 90 -95 18-17
Square 60-70 90 -95 17-16
Square 70-80 90 -95 16-15
Square 80-90 90 -95 15-13
Square 90-110 90 -95 13-11
Square 110-130 90 -95 11-9
Square 130-150 90 -95 9-7

22. 22 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

23. 23 STEEL INDUSTRY - TRAINING HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS

24. GRINDING SAFETY

25. 25 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
Application
Wheel
Breakage
Handling,
Storage
Machine
Maint.
The
Creative
Mind
Speed
Mounting
IMPROPER SPEED
Excessive speed can be a result of
various causes:
• Mounting oversize wheels
• Excessive power (electrical or
pneumatic)
• Wrong mechanical configuration
(gear or pulley ratio)

26. 26 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
PROPER IMPROPER

27. 27 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
• Method of detecting a cracked wheel
• Primarily applies to vitrified grinding wheels
• An undamaged wheel will produce a clear,
ringing tone
• A cracked wheel will produce a dull, dead
tone

28. 28 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
• Your best protection against a broken grinding wheel
• Also protects against contact with rotating grinding
wheel
• Guards prevent over-size wheels being mounted
• Important to position the guard correctly to protect
the operator
• Rule of Thumb – if it doesn’t have a guard, it is the
wrong tool! (very few exceptions)

29. 29 HIGH PERFORMANCE SOLUTIONS • ABRASIVES & COMPOSITE SYSTEMS
• Wear eye (safety glasses)
and face protection (face
shield where applicable)!
• Wear gloves, apron, arm
guards, safety shoes, etc.
• Airborne particulates
control

30. 30
THANK YOU