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Fluid technologies for a better world™

© 2004 The Lubrizol Corporation

Grease

02-12-04 GR100-001


Grease ApplicationsWhen to Lubricate with a Grease

• To reduce lubricant leakage, dripping and spattering• To reduce relubrication frequency• To help seal out contaminants• For equipment that runs intermittently or is kept in storage for

long time periods• For extreme operating conditions (high temperatures,

pressures, shock loads, low speeds)• For badly worn equipment (thicker grease films work well in

worn, increased clearances)• For noise reduction in badly worn equipment (grease acts as a

"cushion")• To suspend (act as a reservoir for) solid additives

GR101-002


Grease ApplicationsGrease Requirements

• High speed• Temperature extremes• Water tolerance• Corrosion protection• Pumpability• Oxidation inhibition• Impact, shock loading

GR101-008


Grease Applications

GR101-011

Thickener StructureDropping Point

°F/°CMax Service

Temperature °F/°C

Sodium soap Fibrous 350/177 200-275/93-136

Calcium soap simple Smooth 270-290/132-143 250/121

Complex Smooth, buttery >450/>232 300/149

Lithium soap simple Smooth 390/199 325/163

Complex Smooth, slightly stringy >450/>232 350/177

Aluminum complex Smooth gel >450/>232 300/149

Clay Smooth >500/>260 350/177

Polyurea Opaque, slightly mealy >450/>232 350/177


Grease ApplicationsSoap Thickened Greases

GR101-012

Type Thickener Characteristics Applications

Aluminum Smooth, gel-like appearanceLow dropping pointExcellent water resistanceSoftening/hardening tendenciesGreatly dependent on shear rate

Lubricate low speed bearingsWet applicationsUsage decreasing

Sodium Rough, fibrous appearanceModerately high dropping pointPoor water resistanceGood adhesive (cohesive) properties

Older industrial equipmentWhere relubrication is frequentRolling contact bearing

Calcium Smooth, buttery appearanceLow dropping pointsGood water resistance

Bearings in wet applicationsRailroad rail lubricant

Lithium Smooth, buttery to slightlyStringy appearanceHigh dropping pointResistant to softening and leakageModerate water resistance

Automotive chassis and wheel bearingsGeneral industrial greaseThread lubricants for oil drilling industry


Grease ApplicationsComplex Soap Thickened Greases

GR101-013

Type Thickener Characteristics ApplicationsAluminum complex Smooth, slight gel-like

appearanceDropping points above 450°FGood water resistanceShorter life at high temperature

Steel mill roll neckRolling and plain bearings

Calcium complex Smooth, buttery appearanceDropping points above 450°FGood water resistanceInherent EP/load-carrying capability

High-temperature industrial and automotive bearing applications

Lithium complex Smooth, buttery appearanceDropping points above 450°FResistant to softening and leakageModerate water resistance

Automotive wheel bearingHigh-temperature industrial service including various roller-element applications


Grease ApplicationsOther Thickened Greases

GR101-014

Type Thickener Characteristics Applications

Polyurea Smooth, slight opaque appearanceDropping points above 450°FGood water resistanceOxidation resistantLess resistant to softening and leakage

Industrial roller-element bearingsAutomotive constantVelocity joints

Organo-clay Smooth, buttery appearanceDropping point above 500°FResistant to leakageGood water resistance

High temperature bearings with frequent relubricationSteel mill roll neckSteel mill roll neck bearings


Grease ApplicationsWhen to Lubricate with a Grease

• Choice depends on:− Expected operating conditions− Lubrication system to be used− Properties of available lubricants

• Greases are frequently used to lubricate machine parts which are difficult to reach during operation

• Greases are especially suitable for severe or extreme operating conditions:− High operating temperatures− Heavy or shock loading− Low speed with high pressure− Intermittent operation

GR101-015


Grease ApplicationsOil versus Grease for Bearings - Advantages

GR101-016

Oil Grease

Excellent heat transfer Simplifies seal designActs as a sealant

Carries away dirt and moisture

Permits prepacking of bearings

Easily controlled lubrication

Requires less frequent lubrication


Grease ApplicationsCompatibility Chart

10-20-97 GR101-075

AluminumComplex Barium Calcium

Calcium12-Hydroxy

CalciumComplex Bentone Lithium

Lithium 12-Hydroxy

Lithium Complex Polyurea

AluminumComplex I I C I I I I C I

Barium I I C I I I I I I

Calcium I I C I C C B C I

Calcium12-Hydroxy C C C B C C C C I

CalciumComplex I I I B I I I C C

Bentone I I C C I I I I I

Lithium I I C C I I C C I

Lithium 12-Hydroxy I I B C I I C C I

Lithium Complex C I C C C I C C I

Polyurea I I I I C I I I I

B = Borderline compabilityC = CompatibleI = Incompatible


Grease ApplicationsReading the Specification Sheet

• Read worked penetration (P60)− Determine grade

• Read dropping point− Estimate heat resistance

• Read base oil viscosity− Estimate suitability for high or low speed application− Estimate suitability for high or low load application− Estimate pumpability

• Read thickener type− Estimate water resistance− Estimate pumpability

01-27-98 GR101-076

Fluid technologies for a better world™


Function and Chemical Composition

01-30-04 GR103-001


Function and Chemical CompositionNLGI Definition

GR103-004

Grease:

“A solid to semisolid product of dispersion of a thickening agent in a liquid lubricant. Additives imparting special properties may be included.”


Function and Chemical Composition

Base Stock86%

Performance Additive

4%

Thickener10%

10-20-97 GR103-005


Function and Chemical CompositionProperties Contributed by Thickeners

GR103-011

Thickener TypeShear

StabilityWater

ResistanceHigh Temperature

Stability

Calcium (Hydrous) M G P (90)

Calcium (Anhydrous) G G M (140)

Lithium G M G (180)

Sodium M-G P G (200)

Calcium Complex M G G (300)

Lithium Complex G M-G G (250)

Polyurea M-G G G (240)

Bentonite Clay M M G (None)G = Good, M = Medium, P = Poor( ): Dropping Point °C


Function and Chemical CompositionProperties Determined by Thickener Alone

• Rheology• Water resistance

GR103-012


Function and Chemical CompositionRheology

• Describes behavior of flowing materials under stress• Shear rate

− Rate at which adjacent layers of a substance move against one another

• Shear stress− Force which must be applied to a substance in

order to cause shear

GR103-013


Function and Chemical CompositionGrease Properties Determined by Base Fluid Alone• Evaporation loss

GR103-018


Function and Chemical CompositionGrease Properties Determined Jointly by Thickener, Base Fluid, and Additives• Consistency• Oxidative and thermal stability• Corrosion resistance• Structure stability• Load carrying capability• Low temperature behavior• Dropping point• Elastomer compatibility

GR103-019


Function and Chemical CompositionThickener

• Solvency of fluid medium in thickener• Solvency of thickener in the fluid medium• Attractive forces between the thickener and the fluid• Capillary forces holding the fluid within the fiber

network• Mechanical interlocking of the fiber network

12-10-96 GR103-029


Function and Chemical CompositionNaphthenic Base Oils

• Soap tends to be smoother• Soap is more translucent• Oil has better affinity for soap• Pour point lower• Low temperature pumpability

12-10-96 GR103-030


Function and Chemical CompositionParaffinic Base Oils

• High temperature stability• Improved oxidation resistance• Soap formation more difficult• Higher soap content

12-10-96 GR103-031


Function and Chemical CompositionSynthetic Base Oils

• Performance at high and low temperatures• Specialty applications• Soap formation difficult• Soap content high

12-10-96 GR103-032


Function and Chemical CompositionVegetable Base Oils

• Biodegradability• Oxidation during heating cycle• Low temperature mobility• High temperature performance• Soap content high

12-10-96 GR103-033


Performance Additives for Grease

• Grease additives may be− Organic

• Chemically activeOr

• Chemically inert− Solid lubricants (inorganic)

GR105-00203-29-05


Performance Additives for GreaseChemically Inert Additives

• Affect a physical property such as structure, rheology, or water tolerance

GR105-003


Performance Additives for GreaseExamples of Chemically Inert Additives

• Viscosity modifiers• Pour Point depressants• Antifoam agents• Emulsifiers• Demulsifiers

GR105-004


Performance Additives for GreaseChemically Active Additives

• Produce their effect through chemical reaction either within the lubricant medium or on the metallic surface

GR105-005


Performance Additives for GreaseExamples of Chemically Active Additives

• Oxidation inhibitors• Rust and corrosion inhibitors• EP/antiwear agents

GR105-006


Performance Additives for GreaseCurrent Chemistry

• Antimony dithiocarbamate• Sulfurized olefin (combinations)• Chlorinated compounds• Barium sulfonate• Lead dithiocarbamate• Zinc dithiophosphates

GR105-011


Performance Additives for GreaseFuture Chemistry

• No lead• No antimony• No zinc• No barium• No chlorine• No sodium nitrite

GR105-012


Performance Additives for GreaseFactors Influencing Additive Selection

• Performance requirements− Product application

• Compatibility− Synergistic/antagonistic reactions

• Environmental considerations− Product application− Odor− Disposal− Biodegradability

• Color• Cost

GR105-015


Performance Additives for GreaseTypes of EP Agents Used in Grease Formulations• Ashless dithiocarbamates• Borates• Calcium acetate• Chlorinated paraffins• Lead naphthenates and carboxylates• Metal dithiocarbamates• Phosphate and thiophosphate esters• Sulfurized olefins and esters• Zinc dialkyldithiophosphates

04-01-98 GR105-018


Performance Additives for GreaseAntiwear Agents

• Borates• Metallic dialkyldithiophosphates• Phosphate and thiophosphate esters• Various molybdenum compounds

04-01-98 GR105-019


Performance Additives for GreaseZinc Dialkyl Dithiophosphates

GR105-020

Antiwear AntioxidantHydrolytic Stability

Thermal Stability

Aromatic Poor Poor Poor Best

Primary Moderate Moderate Moderate Moderate

Secondary Best Best Best Poor


Performance Additives for GreaseOxidation Resistance Factors

• Type of thickener• Relative acidity or basicity• Nature of base oil component

GR105-023


Performance Additives for GreaseResults of Oxidation

• Increase in penetration• Lowering of dropping point• Drying and cracking• Increased uptake of oxygen• Increased acid number• Deposits on bearing surfaces

GR105-024


Performance Additives for GreaseTypes of Oxidation Inhibitors

• Hindered phenols• Aromatic amines• Heterocyclic nitrogen compounds• Metal dialkyldithiophosphates• Metal dialkyldithiocarbamates

GR105-025


Performance Additives for GreaseOxidation Inhibitors

• Aromatic amines− Effective at high temperatures; offer little inhibition

at low temperatures• Alkylated phenols

− Function well at low temperatures; less effective at high temperatures because of volatility

• Metal dithiocarbamates− Effective oxidation inhibitors because of their

ability to scavenge hydroperoxides− Dual functionality as oxidation inhibitors and EP

agents

GR105-026


Performance Additives for GreaseRust Inhibitors

• Usually highly polar oil soluble compounds• Function by adsorption on metal surface to form

protective film• Function by adsorption on metal surface• Form thin protective film which excludes air and

moisture

GR105-027


Performance Additives for GreaseTypes of Rust Inhibitors

• Fatty amines• Fatty amides• Carboxylic acids• Sodium and calcium sulfonates• Barium sulfonates• Sodium nitrite

GR105-028


Performance Additives for GreaseMetal Deactivators Triazole and Thiazole Derivatives• Passivate nonferrous metal surfaces• Compete with sulfur for metal surface to prevent

formation of dark sulfide stains

GR105-029


Performance Additives for GreaseTackiness Agents

Impart surface adhesion• Polymers• Polyisobutylene• Polymethacrylate• OCP (olefin copolymer)• Styrene/diene copolymers

GR105-03007-12-05


Performance Additives for GreaseSolid Additives - Function

• May impart durability as well as EP protection• Most useful in protecting heavily loaded bearings

from fretting wear galling and seizing• Function at the metal surface under boundary

conditions• Provide method for product recognition

GR105-031


Performance Additives for GreaseSolid Additives - Example

• Molybdenum disulfide• Graphite• Powdered zinc• Zinc oxide• Titanium dioxide• Cerium fluoride

01-27-98 GR105-032


Performance Additives for GreaseMultipurpose EP Grease: Typical Additive Package

GR105-034

%

Extreme pressure 2.00Friction modifier 0.50Antiwear agent 0.50Rust inhibitor 0.50Oxidation inhibitor 0.25Metal deactivator 0.25Total 4.00


Performance Additives for GreaseMultipurpose EP Grease: Typical Performance

06-05-05 GR105-035

Additive

Test Method No Yes

Timken OK load D 2509 8 lb. 45 lb.

Four ball wear D 2266 .68 mm .45 mm

Four ball EP D 2596

LWIWeld

20.0160 kg

50315 kg

Rust D 1743 Fail Pass

Oxidation D 942 --- <5.0 psi Lossat 100 hrs.

Copper corrosion D 4048 1A 1B

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