1. COLD ROLLING OILS

2. Contents Our Lab Mill Trials at RDCIS Introduction
Emulsion Management
Popular Brands of Rolling Oils in India
Rolling Mills in India
Rolling Oil Potential
Introduction
Mechanism of Roll Lubrication
Requirements of a Rolling Oil
Trends (Past/Present/Future)
Evaluations of Rolling Oil

3. Cold Rolling Oil
An Oil / Emulsion introduced at the Roll-bite in the process of Cold Rolling to control Friction at the interface of Work Rolls and Strip

4. Various Processes in Steel Rolling

5. Type of Cold Rolling Mills

6. Why Cold Rolling? Limitation of HSM to produce thinner gauge with
Superior surface finish
desired mechanical & metallurgical properties
Potential application of the product in consumer goods industry
Newer cold rolled products are being continuously developed both in bare & coated variety

7. Type of Cold Rolling Mills
2 Hi Mill
Suitable for hot or cold rolling of ferrous and nonferrous metals.
Ideal for breakdown, run down, tempering and skin pass operations. 

8. Type of Cold Rolling Mills
4 Hi Mill
Undesirable contact area results in a bending force which causes edge drop.

9. Type of Cold Rolling Mills
4 Hi Mill
Used both as Non-reversing Mills for intermediate rolling and as Reversing Mills for finish rolling
Smaller rolls reduce thickness of metal being rolled more easily and with much less pressure than large rolls of a 2-High Mill 
This decreased pressure reduces roll bending and separating forces and permits rolling of wider and thinner materials with a more uniform gauge
4-hi mills are a cost-effective means for industry to product a wide range of sheet products . 90% of Mills are of this type.

10. Type of Cold Rolling Mills
Reversing Mills
Advantages
Less Capital Cost
Occupy less space
Any required gauge can be obtained
Disadvantages
Low output
High Roll Consumption
Continuous Mills
Advantages
Suitable for large outputs
Higher gauge accuracy
Disadvantages
High capital cost
Large production of one size product

11. Type of Cold Rolling Mills
4 Hi Tandem Mill

12. Type of Cold Rolling Mills
6 Hi Mill
Provide improved flatness due to their workroll bending mechanism and intermediate roll adjustment in an axial direction.
Main advantages are improved shape of rolled strip, increased reductions and greater rolling efficiency.
Drawbacks :
Complicated and hard to maintain roll cluster unit
Cooling problems resulting from the smaller circumferential area of their working rolls.

13. Type of Cold Rolling Mills
6 HI Mill
Undesirable contact area is virtually eliminated by shifting the intermediate rolls axially.
This can be done quickly and easily, making the HC-MILL the ideal solution for the real world.
Use of the HC-MILL not only significantly improves quality, but has significant ramifications for the system.

14. Type of Cold Rolling Mills
20 Hi Mill

15. Type of Cold Rolling Mills
20 Hi Mill

16. Tandem Mill – Continuous Mill
Modern Tandem Cold Mill consists upto 6 sets of independently driven pairs of Work rolls, each pair being supported by a large no. of back-up rolls
Cumulative Mill reduction could be in the range of 50% - 90%
Ensures high gauge accuracy and proper flatness
Roll separating force involved in rolling 1250 mm wide strip may be as high as 1000T

17. Mechanism of Roll Lubrication
Friction is a necessity as a transmitter of Deformation Energy
Optimization of friction
Adequately high to Ensure traction in the Roll bite
Low enough to optimize Mill Motor Power requirement

18. Mechanism of Roll Lubrication
Oil Pooling at the Bite
Positive Pressure gradient at the inlet zone
Viscous component of the oil diffuse more in the roll bite
Higher Strip temperature ( oC) evaporates water in emulsion
Fatty substance affinity to the strip/roll surface

19. Mechanism of Roll Lubrication
Vo>Vp>Vi
At neutral Point Vx=Vp
Contact angle is about 3-4 Degrees only
Pressure on the rolls buildup from entry to the neutral point and then declines till exit.

20. Mechanism of Roll Lubrication
Lubrication Regimes in
Pre-deformation Zone
Elasto Hydrodynamic
Deformation Zone
Plasto Hydrodynamic
Boundary
EP Lubrication

21. Some Important Formulae

22. Some Important Formulae
Pressure Distribution

23. Functions of a Cold Rolling Oil
Lubrication:
Control friction, wear and surface damage of rolls and strip
Scavenging:
Heat
Dirt
Wear Debris

24. Requirements of a Rolling Oil
Optimum lubricity, high film strength, shear stability, high plate-out characteristics
High heat transfer co-efficient
Optimum Emulsion stability/Good chemical stability
Long emulsion life
Easy maintenance
High cleanliness properties
Good Burn off characteristics
Good emulsion detergency
Minimum soap formation
Easy disposal
Environment friendliness
Bio-degradable

25. Additional Requirements of a Rolling Oil
Good rust/corrosion protection capacity
Good resistance to tramp oil contamination
Easy removability after rolling
Complete System Compatibility
Rolling Mill & Strip Components
Pickling Oil/acid traces carry over from pickling line
Economical

26. Constituents of Cold Rolling Oils
Lubricant Base (80% - 90%)
Natural Oils
Fats & their Derivatives
Mineral Oils
Synthetic Esters
Boundary Additives
Molecules with permanent dipole moment like Derivatives of Fatty Oils (acids, alcohols, amines)
Long chain acids are preferred
Neutral soaps of Esters

27. Constituents of Cold Rolling Oils
Emulsifiers
HLB Value
Emulsion stability
Oil Particle Size
Plate Out
Shear Stability
Dispersant / Surfactants
EP & AW Additives
Chlorinated Paraffins
Sulfurized Mineral Oils/Fats
Chloro-sulphides
Sulfur-phosphorus compounds
Nitrogen-phosphorus compounds

28. Properties of Rolling Oils
Viscosity
Higher Film thickness Viscosity
Saponification Value
Indicates amount of Esters present
Higher SAP value means better lubricity
Higher SAP may impair Cleanliness behavior of oil
Free Fatty Acid (FFA)
Help decreasing friction due to adsorption on strip & roll surface thus provide good boundary lubrication
Prone to oxidation, polymerization and formation of sticky deposits on storage.
Affects Cleanliness behavior of oil

29. Properties of Rolling Oils
Iodine No.
Indicates degree of un-saturation of fatty materials/esters
Pour Point
Lower value is desired
May help cooling efficiency
Too low pour oils using short chain compounds may possess poor lubricity & load bearing ability
pH Value
Vital for emulsifier’s effectiveness
Affected by
Carryovers from pickling lines
Water Quality
Tramp Oils
Degeneration/Oxidation of the Rolling Oil itself

30. Properties of Rolling Oils
Ash Content
Low ash formulations are preferred
Oil Particle Size
Greatly affects Lubricity, Plate-out, Iron Content of emulsion
Indication of shear stability of the oil
Parameters
Sheet Rolling
Tin Plate Rolling
Mean Particle Size, µ
2 - 5
ESI,%
Oil Plate-out, mg/m2
Iron Content, ppm

31. Trends Palm Oil High Mol. Wt. Polymers Synthetic Esters Natural Oil/
Fats/
Derivatives
High
Mol. Wt.
Polymers
Fatty Oils &
Mineral Oils
Synthetic
Esters

32. Evaluations of Rolling Oils
Laboratory Tests
Physico-chemical Tests
Functional Tests
Tribological Tests
Lab. Mill Trial
Industrial Trials

33. Laboratory Tests of Rolling Oils Physico-chemical Tests
Ash Content, % Wt
Carbon Residue, CCR, % Wt
Flash Point, COC, oC
Free Fatty Acid, Oleic %
Iodine Number
Kinematic 40 oC, cSt
pH of 2% Emulsion in Distilled Water
Pour Point, oC
Saponification Value, mg of KOH/gm

34. Laboratory Tests of Rolling Oils Functional Tests
Burn-Off Characteristics
Emulsion Stability Index
Mean Particle Size, µm
Plate-out Characteristics
Cleanability
Iron Corrosion
HLB Value
Staining Tendency

35. Tribological Test Rigs
Contact Configuration
Type of Contact
Soda Pendulum
Pin on Two Pairs of Balls
Point Contact
Amsler Wear Test
4 Pairs of Crowned Discs
Line Contact
SRV Test Rig
Ball or Roller on Disc
Point/Line Contact
LFW1 Rig
Ring on Block
Ring Compression Test
Ring on Platen
Surface Contact
Plint Tribometer
Pin on Sheet

36. Tribological Test Rigs LFW 1 Oscillating Test
Test Description
A steel block pressed against a lubricated oscillating ring.
Test Result
Static and dynamic friction coefficient µ, wear in mm, life time of lubricant
Standards
ASTM D 2714, ASTM D 2981, ASTM D 3704

37. Tribological Test Rigs LFW 1 Rotating Test
Test Description
A steel block pressed against a lubricated rotating ring.
Test Result
Static and dynamic friction coefficient µ, wear in mm, life time of lubricant
Standards
ASTM D 2714, ASTM D 2981, ASTM D 3705

38. Tribological Test Rigs Falex Pin & Vee Block Tester
Test Description
A lubricated, rotating steel shaft between two V-shaped steel blocks under specified load.
Test Result
Friction coefficient µ, wear in mm, endurance life in h, load carrying capacity N
Standards
ASTM D 2670, ASTM D 2625, ASTM D 3233, ASTM D 3704

39. Tribological Test Rigs Falex Pin & Vee Block Tester

40. Tribological Test Rigs Falex Pin & Vee Block Tester

41. Tribological Test Rigs SRV Tester

42. Tribological Test Rigs SRV Tester
Test Description
Measure friction and wear under oscillatory or rotational motion.
Test Result
Coefficient of friction µ, wear rate in mm  
Standards
DIN 51834, ASTM D , DIN 50324

43. Tribological Test Rigs Four Ball Machine
Test Description
Wear properties and weld load of consistent lubricants in a four ball system (rotating ball on three fixed balls).
Test Result
Welding load in N, wear scare in mm
Standards
DIN 51350

44. Tribological Test Rigs Amsler Wear Test

45. Tribological Test Rigs Amsler Wear Test

46. PIN ON DISC TRIBO TESTER

47. Plint Tribometer

48. Emulsion Management Good emulsion management provides
Consistent performance of oil
Longer emulsion life

49. Emulsion Management What all to manage of an emulsion? Concentration
Temperature pH
Conductivity
Oil Particle Size (OPS)
Tramp Oil
Iron fines
Bacterial Count

50. Emulsion Concentration
Variations in actual production line may be high owing to:
Disproportionate Oil addition
Evaporation of Water
Change in emulsion characteristics of oil
Skimming of tramp oil
Online oil concentration measurement helps
The oil content directly relates to the velocity of sound in the fluid. A change of 1% oil content brings about an change of approx. 2 m/s.

51. Emulsion Temperature Higher emulsion temperature than desired
Brings down oil film thickness by decreasing viscosity
Declines Cooling Efficiency
Emulsifier’s behavior may get affected
Normally kept within 45 – 55oC

52. Emulsion pH Emulsifier system is pH sensitive
Causes of pH disturbances
Acid carry over from pickling line
Inferior feed water for emulsion
Tramp Oil mixing
Preferred pH range: 5.0 – 7.0
pH < 5.0
Increase Particle size
Corrosion Problem
Erratic Rolling
pH > 7.0
Reduce Particle size
More metallic soaps
Affects cleanliness

53. Emulsion Conductivity
Major contributors: H+, OH-, Cl-, SO42-
Minor Contributors: Ca2+, Mg2+, Na+, K+
Conductivity of Emulsion < 200 µS/cm
Should never exceed 500 µS/cm
Conductivity of
De-mineralized Water < 10 µS/cm
Industrial Hard Water < 500 µS/cm

54. Tramp Oil
Oil in emulsion that doesn't derive from the emulsion concentration itself is uncontrollable and therefore undesirable.
Sources of tramp oil
oil leaks from transmissions, hydraulic systems and other lubrication points

55. Negative effects of Tramp Oil
Loss of cooling & wetting properties
Deplete emulsifiers
Nullifying rust-inhibitors
Cuts off air and thereby provides an excellent base for growth of anaerobic bacteria
Reduce amount of sulfur additives
Drop in pH
Create bad smell
Low pH increases ionization of heavy metal in coolant and this in turn may create unhealthy working atmosphere.

56. Desired Values of Some Important Emulsion Parameters1
Chloride in Pickling Rinse Water
< 60 ppm 2
Chloride on Pickled Strips
< mg/ft2 3
Emulsion Conductivity
< 500 mS/cm2 4
Hardness of Water
< 250 ppm 5
Bacteria
< 5 x 106 counts/ml 6
Yeast
< 200 counts/ml 7
Tramp Oil
< % 8
Iron in Emulsion
< 200 ppm 9
pH Variation 10
Iron on CR Strip
< 100 mg/m2 11
Oil on CR Strip 12
Carbon on Annealed Strip
< 7 mg/m2

57. Emulsion Management FFA Analysis of Used Extracted Oil
Usually lower than Fresh Oil as some FFA are lost due to soap formation with Iron & hard water salts
Lowered due to Mineral Oil Contamination
May increase due to excessive bacterial activity

58. Emulsion Management Analysis of Used Extracted Oil SAP Value
Lowered with contamination of Tramp Oils
% drop Indicates reduction of the active oil in emulsion
Should not fall below 70%
IR Spectroscopy
Predicts Ester content & Fatty acid concentration
Identify contamination

59. Cold Rolling Mills in India
No. of units
Unit Capacity (TPA)
Width Range (mm)
Total capacity 20
up to 30,000
upto 450
240,000 16
up to 72,000
570,000 15
up to 300,000
1,420,000 5
1,310,000 2
> 1,000,000
> 1560
2,690,000
Total
6,230,000

60. Rolling Oil Potential in India
Specific Rolling Oil consumption in Cold Rolling:
1.2 kg/T of Rolled Sheet for Mineral Oils
0.6 kg/T of Rolled Sheet for Semi-synthetic/Synthetic Oils
Considering the above, Cold Rolling Oil potential would be about 3500 – 5000 KL per Annum

61. Popular Cold Rolling Oils
Manufacturer
Brand Name
D A Stuart
Rolkleen 1000, 2000, 3000
Quaker Chemicals
Quakerol CA 29
B&L
Balmerol Aquaroll 431, 432
Indian Oil
Servo Steerol C4, C6
HPCL
HP Cold Rolling Oil
Houghton
Houghto-Roll