doi: 10.18668/ng.2018.02.06 oil and gas institute ......din 51825 standard lubricants –...

121

NAFTA-GAZ, ROK LXXIV, Nr 2 / 2018

DOI: 10.18668/NG.2018.02.06

Elżbieta Trzaska, Agnieszka Skibińska

Oil and Gas Institute – National Research Institute

Determination of low-temperature properties of lubricating greases

The article presents the results of laboratory tests of low-temperature properties of lithium complex greases produced on base oils, characterized by a different chemical structure. Low-temperature properties of lubricating greases were determined according to the following test methods:• low-temperature cone penetration – PN-ISO 13737,• flowpressure–DIN51805-2,• apparentviscosity–PN-C-04146.Itwasfoundthatthelow-temperaturepropertiesoflubricatinggreasescanbemodifiedbyintroducingoilswithadifferentchemical structure into the oil base. The lowest temperature of application of the tested lithium complex greases was determined.

Key words: lubricating greases, low-temperature properties, base oils.

Badanie właściwości niskotemperaturowych smarów plastycznych Wartykuleprzedstawionowynikibadańlaboratoryjnychwłaściwościniskotemperaturowychsmarówlitowychkomplekso-wych,wytworzonychnawytypowanycholejachbazowychoróżnymcharakterzechemicznym.Właściwościniskotempera-turowesmarówplastycznychoznaczanowedługnastępującychmetodbadawczych:• penetracjawniskiejtemperaturze–PN-ISO13737,• ciśnieniepłynięcia–DIN51805-2,• lepkośćstrukturalna–PN-C-04146.Stwierdzono,żewłaściwościniskotemperaturowesmarówplastycznychmożnamodyfikować,poprzezwprowadzeniedobazyolejowejolejówoodmiennymcharakterzechemicznym.Ustalononajniższątemperaturęstosowaniabadanychpróbeksmarówkompleksowychlitowych.

Słowakluczowe:smaryplastyczne,właściwościniskotemperaturowe,olejebazowe.

Lubricatinggreasesaresolidtosemifluidsubstancesform-ing by dispersing a solid phase (thickener) in a liquid phase (baseoil).Theliquidphaseconstitutes70÷90%(m/m) and it is a basic component of the grease. The character of this phase determines, among others, the low-temperature properties, lubricating properties, oxidation stability, and changes in the propertiesdependingontemperature[3,7,9÷14].

A suitability of the oil for production of greases is evaluated based on the oil’s properties such as: viscosity and viscos-ityindex,rheologicalpropertiesatlowtemperatures,flashpoint, lubricating properties and the ability to protect from corrosion[15,16].

Selection of a proper base oil depends on the oil’s kinematic viscosity at the working temperature of the bearing being lubri-cated. Most favourably, as the base oil for grease production, the oil characterised by a viscosity close to that of the oil, with which a given friction pair should be lubricated if it had to be lubricatedwithanoil[7,8].

While selecting the base oil for production of a grease with a required range of the low-temperature limit of the grease application, the pour point of the base oil should be determined, value of which decides to the highest degree on thelow-temperaturepropertiesofgreases[2].Anadequatelylow pour point of the base oil ensures a good operation of

Introduction

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122 Nafta-Gaz, nr 2/2018

the bearing at low-temperature limit of the grease applica-tion[16].

Lithiumgreasespreparedonparaffinicbaseoilsdonotexhibit good low-temperature properties because of the level of the base oil’s pour point. Slightly better low-temperature properties are exhibited by greases prepared on naphthenic base oils.Useofasyntheticoil(e.g.,polyalphaolefinoil,PAO)intheoil base ensures better low-temperature properties. Introduction of a diester oil, characterised by an extremely low pour point and a good thermal oxidation stability, into the PAO, leads to a synergy of both oil bases and an improvement of the low-temperatureproperties[20].

Selection of the base oil used for the grease production, has asignificantimpactonthebehaviourofthegreaseduringflow,particularlyatlowtemperatures.Paraffinicbaseoilscontainsignificantamountsofsaturatedhydrocarbons,whichobstructthegrease’sflowwhilecrystallising.Depressantsaddedtothebase oil during the production of the grease, prevent aggrega-tionofparaffincrystalsandthusimprovethegrease’sflowatlowtemperatures.Unliketheparaffinicoils,naphthenicoilstypically do not contain large amounts of molecules which maycrystalliseatlowtemperature[4].

Greases based on synthetic oils are used under circumstances, in which mineral oils cannot be used because of the conditions (e.g.,extremelyhighorlowtemperatures,highpressure)[20].

Technological progress requires that greases meet increas-ingly high operational requirements, among others, more and more broad range of the operating temperature, and a more perfectthermaloxidationstability.Usingnon-conventionalbase oils, complex high-temperature greases may be obtained, which meet these requirements, with good low-temperature properties, ensuring start-up and failure-free operation of machinesandinstallations[1,7,10,12÷14,20].

Lithium complex greases, currently constituting approx. 20%ofallgreasesproducedglobally,allowforincreasingtheoperational temperature of the grease in relation to ordinary lithium greases, while maintaining other favourable properties, such as: thermal and mechanical stability, and high resistance towater.Droppingpointofgreasesofsuchatypeisapprox.280°C,whilethatofordinarylithiumgreasesisapprox.190°C.Lithium complex greases found wide application for lubrica-tion of friction pairs in automotive vehicles and in various industrialequipment[3,5,6,8,11].

Operation of machines and installations at a low tempera-ture(below0°C)requiresuseoflubricatinggreaseswithgoodlow-temperature properties, ensuring start-up and failure-free operation[1,20].Specialistlubricatinggreasesareagroupof lubricants, which include greases with a lower applica-tionlimitbelow–35°C,resistanttotemperatureshigherthan

230°C,resistanttowaterandhighloads(400÷600kG,withafrequencyofrotation1200–1500rpm)[2].

To determine operating conditions of lubricating greases, it is necessarytocarryouttestsincludedinthePN-ISO6743-9stan-dard[24].Thetestresultsallowalsofordeterminingtheclas-sificationsymbolofthegrease,forinstanceISO-L-XCDFB 2, including: • theISO initials,• letter“L,”definingtheclassofthelubricants,• letter“X,”definingthefamilygrease,and four symbols characterising the properties of the grease: • 1st symbol – the lower operating temperature C(–30°C),• 2nd symbol – the upper operating temperature D(140°C),• 3rd symbol – level of the water resistance and protection

against corrosion F (water contamination and anti-rust protection),

• 4th symbol – the ability to lubricate under high loads B (extreme pressure (EP) properties),

and NLGI consistency number 2 (based on worked penetra-tion range).

The PN-ISO 12924 standardŚrodki smarowe, oleje przemysłowe i produkty podobne (Klasa L) – Grupa X (Smary) – Wymagania [Lubricants, industrial oils and related products (Class L) – Family X (Greases) – Specification]recommendscarrying out the following tests to determine the low-temper-ature properties of greases or the lower operating temperature (1stsymbolintheclassificationsymbolofthegreaseacc.toPN-ISO6743-9)[24,26]:• startingtorqueandrunningtorque–ASTMD1478orNFT

60-629[17,21],• flowpressure–DIN51805-2[18],• low-temperaturepenetrability–PN-ISO13737[25].

Dependingonthetesttypewhichhasbeenthebasefordetermination of the lower operating temperature of the grease, Symbol1iscompletedbyasuffixletterbetweenbrackets:• (L)–starting/runningtorque,• (F)–flowpressure,• (P)–low-temperaturepenetrability.

ThePN-C-96014standardŚrodki smarowe – Smary plas-tyczne klasy K – Klasyfikacja i wymagania, introducing the DIN51825standardLubricants – Lubricating greases K – Classification and requirements,todefinethelow-temperatureproperties necessary to determine the lower operating tempera-ture,recommendscarryingoutthefollowingtest[23]:• flowpressure,accordingtotheDIN51805-2standard[18],

requiredlowerthanorequalto1400hPa,• torque,accordingtotheIP186standard[19],requiredstatic

torquelowerthanorequalto1000mNmandrequireddynamictorquelowerthanorequalto100mNm[23].

artykuły

123Nafta-Gaz, nr 2/2018

Studies on the low-temperature properties of prepared samples of lithium complex greases were carried out according to the following test methods:• PN-ISO13737:2011Przetwory naftowe i środki smarowe

– Pomiar penetracji smarów plastycznych w niskich tem-peraturach penetrometrem ze stożkiem [Petroleum products and lubricants – Determination of low-temperature cone penetration of lubricating greases],

• DIN51805-2:2016Prüfung von Schmierstoffen – Bestim-mung des Fließdruckes von Schmierfetten mit dem Verfahren nach Kesternich – Teil 2: Automatisches Verfahren [Testing of lubricants – Determination of flow pressure of lubricating greases according to Kesternich method – Part 2: Automatic method],

• PN-C-04146:1963Przetwory naftowe – Pomiar lepkości strukturalnej smarów stałych [Petroleum products – Meas-urement of apparent viscosity of lubricating greases].

Determination of low-temperature cone penetration acc. to PN-ISO 13737

The method for determination of low-temperature cone penetrationacc.tothePN-ISO13737standard[25]consistsin a measurement of grease penetration of a cooled sample underspecificconditionsasperthetesttemperature,usinga cone cooled to the same temperature. To carry out the test, two grease samples were prepared in full-scale grease cups, one for temperature control, the other for the penetration measure-ment. The grease sample for the penetration measurement was workedby60fulldoublestrokesoftheplunger,andthen,the

Table1.Testsfordeterminationoftheloweroperatingtemperature[26]

The lowest application temperature

[°C]

Startingtorque[mN·m]Flowpressure

[hPa]Penetrability[1/10mm]

valuerunning torque[mN·m]

1st symbol value value 1st symbol value 1st symbol

0

≤1000

A (L)

≤100 ≤1400

A(F) ≥140 A (P)–20 B (L) B(F) ≥120 B (P)–30 C (L) C(F) ≥120 C (P)–40 D(L) D(F) ≥100 D(P)<–40 E (L) E(F) ≥100 E (P)

– Test methods:ASTMD1478orNFT60-629

Test method:DIN51805-2

Test method:ISO 13737

Aim of the paper

Theaimofthepaperwastodeterminetheinfluenceofa base oil used in lithium complex greases on the properties of

these greases at a low temperature, namely their consistency, flowpressureandapparentviscosity.

Methodology of the studies

surface of the grease was evened. Both cups with the grease and the penetrometer cone were placed in a cooling chamber, at the testtemperature.Aftercoolingfor4hours,thecooledconewasinstalledinthepenetrometer(Figure1),andthen,theunworkedpenetration measurement of the grease was carried out.

Determination of flow pressure of lubricating greases acc. to DIN 51805-2

Acc.totheDIN51805-2standard[18],flowpressureisthepressure required to push a grease stream through a standardized nozzle,underconditionsdefinedinthestandard(Figure2).Astandardizedsteelnozzlewasfilledwiththegrease,sealedwithasiliconeo-ringthenplanedinanapparatus(Figure3)equipped with a thermostatic block. After reaching the given temperature,thepressureisincreasedautomaticallybyadefinedincrement(dependingontheflowpressureofthegrease)with

Fig.1.Penetrometerfordetermination of grease

penetration (photo: INiG – PIB)

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Determination of apparent viscosity of the greases acc. to PN-C-04146

The method for determination of apparent viscosity of solid greasesaccordingtothePN-C-04146standard[22]consistsinforcing the grease through a capillary tube under a decreasing pressure, obtained using a plunger with a known characteris-tics. The apparatus allows for carrying out the measurement in a wide temperature range due to the fact that the medium is supplied from the thermostatic chamber. The apparatus consistsofthreeglasscapillarytubesfixedintometalsocketswithglue(Figure4),havinglengthsofapprox.11.5cmanddiametersofapprox.0.02,0.05,and0.1mm.A proper capillary tube is selected depending on the test temperature, the type and NLGI consistency number of thegrease.TheAKW-2automaticcapillaryviscometerisshowninFigure5.Thecapillarytubewasfilledwiththegrease and installed in the apparatus. The given measure-ment temperature was obtained supplying coolant from a cryostat to the chamber with the capillary tube. After the test temperature was reached, the apparatus was started.Duringthemeasurement,theapparatusplottedcurves representing pressure change in the chamber

–thegreaseflowedthroughthecapillarytubedrivenbytheexpandingspring(Figure6).Basedontheobtainedcurvesand characteristic data of the apparatus, shear stress and de-formation rate gradient of the grease were calculated. After the calculation of these quantities, a graph was plotted being a basis for the determination of the apparent viscosity for any deformationrategradientofthegrease(Figure7).

30-secondintervals,untilthegreasestreamispushedthroughthe nozzle – this pressure constitutes the measurement result andiscalledflowpressureoflubricatinggreases.

Fig.2.Nozzlewiththegreasefortheflowpressureof lubricating greases test

(photo: INiG – PIB)

Fig.3.Apparatusfortheflowpressureoflubricatinggreasestest (photo: INiG – PIB)

Fig.7.Graphforthedeterminationofapparentviscosityatanydeformationrategradientofthegrease(e.g.:10s–1,thenlgD=1)

Fig.6.Curvesrepresentingthepressurechangesinthechamberduringthemeasurement[23]

Fig.5.AKW-2automaticcapillaryviscometer (photo: INiG – PIB)

Fig.4.Capillarytubefordeterminationofapparentviscosity of the greases (photo: INiG – PIB)

3,0

3,1

3,2

3,3

3,4

3,5

3,6

3,7

3,8

3,9

4,0

4,1

4,2

4,3

4,4

4,5

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8 1,9 2,0 2,1 2,2 2,3

Logarithm

of she

ar stress [lg τ]

Logarithm of deformation rate gradient of the greases [lg Ď]

artykuły


Lithium complex greases were obtained by a standard production procedure, including the following operations:• preparationofasoapconcentrateinabaseoil–approx.

50%ofthebaseoilwasheatedtoatemperatureof80÷90°C;bothacids,12-hydroxystearicacidandsebacicacid,weredosed;afterthedissolutionoftheacids,lithiumhydroxideinawatersuspension(1:1)wasaddedin4portionsduringapprox.2hours;thesaponificationprocesswascarriedoutinareactoratatemperatureof90±5°Cfor1hour,

• dewateringofthesoaps–thewaterwasevaporatedat100÷120°C,

• dispersingofthesoapsinthebaseoil–theremainingamount of the oil was added and the reaction mixture was heatedgraduallytoatemperatureof170±5°C,whichwasmaintainedforapprox.0.5hour,

• greasecooling–thegreasewascooleddynamically,• finaltreatmentofthegrease–thegreasewascooledto

atemperatureof60°C,andhomogenisedinacorundumFryma-typemill,usingaslitof0.2mm.GreasesNLGIconsistencynumber2workedpenetration

range–60doublestrokes–265to295[mm/10]anddroppointofapprox.280°Cwereobtained.

Samples for the tests

Base oils commonly used by lubricants manufacturers for production of lithium complex greases were selected: • aparaffinicoil(denotedwithP), of group I acc. to API, • anaphthenicoil(denotedwithN), of group V acc. to API,

• syntheticpolyalphaolefinoil(denotedwithS), of group IV acc. to API.The determined properties of the base oils and their com-

positionsareshowninTable2.

Table2:Thedeterminedpropertiesofthebaseoilsandtheircompositions

Sample No. 1 2 3 4 5 6 7 8 9

Oil base composition [%(m/m)]

P P:N N P:S S

100 70:30 50:50 30:70 100 70:30 50:50 30:70 100

PropertiesKinematic viscosity:–at40°C[mm2/s]–at100°C[mm2/s]

100.70010.960

101.20010.230

103.1009.904

105.6009.535

75.4009.661

107.2008.927

64.4009.049

56.9308.608

46.9307.891

Viscosity index 92 77 66 52 106 28 117 125 138Pourpoint[°C] –12 –15 –21 –30 –18 –30 –24 –33 –57Flashpoint(COC)[°C] 220 216 214 214 227 214 234 240 260

Method for preparation of the grease samples for the tests

Studies on low-temperature properties

Penetration of the greases at low temperature acc. to PN-ISO 13737

Samples of lithium complex greases, prepared using the base oils from selected API groups on compositions of these oilsweresubjectedtopenetrationtestsatlowtemperature,inthetemperaturerangeof0°Cto–30°C.ThetestresultsareshowninTables3–4andinFigs.8–9.

Based on the obtained results, it was found that among the greases produced on P, N and S oils, the grease on the S oil is characterised by the smallest consistency change with a decrease in temperature, and it exhibits the highest penetra-tionvalueatatemperatureof–30°C.

Among the greases produced on the P:N and P:S, oil com-positions,thesampleswitharatioof70:30exhibitthelargest

penetration change with a decrease in the test temperature, andthesampleswitharatioof30:70exhibitthesmallestpenetration change.

The greases produced on the P:N and P:S oil composi-tions are characterised by the following dependence: an increase in the share of the N and S oil is accompanied by a decrease in the dependence of the greases’ consistency on the temperature.

While comparing the greases produced on the P:N oil compositions with analogous greases produced on the P:S oil compositions, it was found that higher penetration values (a softer grease) at negative temperatures are obtained for the compositions with the S oil, which is connected with its lower flowtemperature.

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Flow pressure of the greases acc. to DIN 51805-2Fortheobtainedsamplesoflithiumcomplexgreases,flow

pressurewasdeterminedinthetemperaturerangeof30°Cto–40°C.ThetestresultsareshowninTables5–6andinFigs.10–11.

Atatemperatureof–30°C,thegreasesontheP oil and on the P:Ncompositionwitharatioof70:30werecharacterisedbyaflowpressureexceedingthedetectionlimitoftheapparatus.

ThelowestflowpressurewasexhibitedbythegreaseontheN oilanditamountedtoapprox.1400mbar.

Atatemperatureof–40°C,thegreasesontheP and N oils, and on the P:Scompositionwitharatioof70:30exhibitedaflowpressureexceedingthedetectionlimitoftheapparatus.ThelowestflowpressurewasexhibitedbythegreaseontheSoilanditamountedtoapprox.700mbar.

Fig.8:Low-temperatureconepenetrationofgreasesamples–depending on the share of the naphthenic oil in the oil base

Fig.9:Low-temperatureconepenetrationofgreasesamples–depending on the share of a synthetic oil in the oil base

Fig.10:Flowpressureofgreasesamples–depending on the share of the naphthenic oil in the oil base composition

Table 3. Low-temperature cone penetration of grease samples – depending on the share of the naphthenic oil in the oil base

Sample No. 1 2 3 4 5

P:N oils share [%(m/m)] 100 70:30 50:50 30:70 100

PropertyWorked penetration at 25°C[mm/10] 280 277 279 273 273

Penetration[mm/10]:–at0°C–at–10°C–at–20°C–at–30°C

207186152107

238209179119

223205151129

201179161133

201189173145

Table4.Low-temperatureconepenetrationofgreasesamples–depending on the share of a synthetic oil in the oil base


P:S oils share [%(m/m)] 100 70:30 50:50 30:70 100

PropertiesWorked penetration at 25°C[mm/10] 280 255 278 285 273

Penetration[mm/10]:–at0°C–at–10°C–at–20°C–at–30°C–at–40°C

207186152107–

217205175145–

231199177165–

229211195175143

219213173169161

Table5.Flowpressureofgreasesamples–dependingon the share of the naphthenic oil in the oil base


P:Noilsshare[%(m/m)] 100 70:30 50:50 30:70 100

PropertiesFlowpressure[mbar]:–at30°C–at20°C–at10°C–at0°C–at–10°C–at–20°C–at–30°C–at–40°C

102120153203415851–*

–*

8090128164319550–*

–*

1031111341663024241541

–*

1111281612974086141488

–*

1021221613124537501400

–*

*Flowpressureexceedsthedetectionlimitoftheapparatus.

0

50

100

150

200

250

‐30‐20‐10

0

Pene

tration[m

m/10]

Temperature [°C] sample 1 sample 2 sample 3 sample 4 sample 5

0

50

100

150

200

‐30‐20‐10

0

Pene

tration[m

m/10]

Temperature [°C] sample 1 sample 6 sample 7 sample 8 sample 9

0

200

400

600

800

1000

1200

1400

‐30‐20

‐100

1020

30

Flow

pressure [m

bar]

sample 1 sample 2 sample 3 sample 4 sample 5

artykuły


Based on the obtained results, it was found that the lower the testtemperature,thehighertheflowpressure.Atatemperatureabove0°C,theflowpressurevaluesforalltestedgreasesamplesare similar, they do not depend on the character of the base oil.

While comparing the greases produced on the P:N oil compositions with analogous greases produced on the P:S oilcompositions,itwasfoundthatalowerflowpressureisobtained for the compositions with the S oil, which is connected withitsflowtemperature.

Apparent viscosity of the greases acc. to PN-C-04146Fortheobtainedsamplesoflithiumcomplexgreases,appar-

entviscositywasdeterminedinthetemperaturerangeof0°Cto–30°C.Foreachtemperature,apparentviscositywasreadatfollowingdeformationrategradientsofthegrease:10s–1, 25s–1,and100s–1.ThetestresultsareshowninTables7–8.

The greases produced on the N oil are characterised by the highestvaluesofapparentviscosity(atadefinedvalueofthede-formation rate gradient of the grease) in the temperature range of

Fig.11.Flowpressureofgreasesamples–depending on the share of a synthetic oil in the oil base

Table6.Flowpressureofgreasesamples–dependingon the share of a synthetic oil in the oil base


P:Soilsshare[%(m/m)] 100 70:30 50:50 30:70 100

PropertiesFlowpressure[mbar]:–at30°C–at20°C–at10°C–at0°C–at–10°C–at–20°C–at–30°C–at–40°C

102120153203415851–*

–*

1041441461703095361152

–*

13013414218128749111491878

1241441471602814857161512

148160170237282338482718

* Flow pressure exceeds the detection limit of the apparatus.

Table 7. Apparent viscosity of grease samples – depending on the share of the naphthenic oil in the oil base


P:N oils share [%(m/m)] 100 70:30 50:50 30:70 100

PropertiesApparent viscosity, Pa · s, at a deformation rate gradient of the greaseof10s–1

–at0°C 263 270 309 363 437–at–10°C 476 550 663 750 871–at–20°C 1585 1600 1620 1638 1660–at–30°C 3617 3329 3137 2944 2656Apparent viscosity, Pa · s, at a deformation rate gradient of the greaseof25s–1


–at0°C 57 62 85 93 155–at–10°C 114 121 175 180 229–at–20°C 218 230 245 260 288–at–30°C 7675 5497 4045 2593 415

Table8.Apparentviscosityofgreasesamples– depending on the share of a synthetic oil in the oil base


P:S oils share [%(m/m)] 100 70:30 50:50 30:70 100

PropertiesApparent viscosity, Pa · s, at a deformation rate gradient of the greaseof10s–1

–at–0°C 263 210 200 182 186–at–10°C 476 377 331 281 251–at–20°C 1585 730 663 517 380–at–30°C 3617 1254 1047 832 562Apparent viscosity, Pa · s, at a deformation rate gradient of the greaseof25s–1


–at0°C 57 49 46 43 41–at–10°C 114 89 82 76 57–at–20°C 218 172 151 144 97–at–30°C 7675 229 182 177 186

0

500

1000

1500

2000

‐40‐30

‐20‐10

010

2030

Flow

pressure [m

bar]

sample 1 sample 6 sample 7 sample 8 sample 9

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0°Cto–20°C,whileatatemperatureof–30°C,highestvaluesofapparent viscosity characterises the greases produced on the oil P.

The greases produced on the S oil are characterised by the lowestvaluesofapparentviscosity(atadefinedvalueofthedeformation rate gradient of the grease). In the temperature range of0°Cto–20°C,anincreaseintheamountoftheN oil in the greases produced on the P:Noilcomposition(atadefinedvalueof the deformation rate gradient of the grease) is accompanied by an increase in the apparent viscosity at the given test tem-perature.Atatemperatureof–30°C,areversedependenceis

observed, an increase in the amount of the N oil is accompanied by a decrease in the apparent viscosity. In the temperature range of0°Cto–20°C,anincreaseintheamountoftheS oil in the greases produced on the P:Soilcomposition(atadefinedvalueof the deformation rate gradient of the grease) is accompanied by a decrease in the apparent viscosity at the given test temperature.

It was found that a decrease in the test temperature is accom-panied by an increase in apparent viscosity of the greases. At the given temperature, an increase in the deformation rate gradient of the grease is accompanied by a decrease in its apparent viscosity.

Summary

Studies on low-temperature properties of lithium complex greases were carried out, prepared on the following oils: a par-affinicoil(groupI),anaphthenicoil(groupV),asyntheticoil(group IV), and on their compositions.

Studies on the low-temperature properties of prepared samples of lithium complex greases were carried out according to the following test methods:• PN-ISO13737:2011–conepenetrationofthegreasesat

low temperature,• DIN51805-2:2016–flowpressure,• PN-C-04146:1963–apparentviscosity.

It was found that the low-temperature properties of lubricat-inggreasescanbemodifiedbyintroducingoilswithadifferentchemical structure into the oil base.

The lower operating temperature of the tested lithium com-plex greases was determined:• basedontheresultsoftheconepenetrationatlowtem-

perature, amounting to:

– –20°Cforthegreasepreparedontheparaffinicoilandfor the greases prepared on compositions of the paraf-finicandnaphthenicoils,

– –30°Cforthegreasepreparedonthenaphthenicoiland for the greases prepared on compositions of the paraffinicandpolyalphaolefinoils,

– –40°Cforthegreasepreparedoncompositionsoftheparaffinicoilwiththepolyalphaolefinoilshareofatleast70%(m/m);

• basedontheflowpressure,amountingto: – –20°Cforthegreasepreparedontheparaffinicoilandoncompositionsoftheparaffinicoilandthepolyal-phaolefinoil,

– –30°Cforthegreasepreparedonthenaphthenicoil, – –30°Cforthegreasepreparedoncompositionsoftheparaffinicoilwiththepolyalphaolefinoilshareofatleast30%(m/m),

– –40°Cforthegreasepreparedonthepolyalphaolefinoil.

Pleaseciteas:Nafta-Gaz2018,no.2,pp.121–129,DOI:10.18668/NG.2018.02.06

ArticlecontributedtotheEditor6.11.2017.Approvedforpublication12.12.2017.

The article was written on the basis of a research work entitled: Study on a possibility to modify the low-temperature properties of lubricating greases–INiG–PIBworkcommissionedbytheMinistryofScienceandHigherEducation;orderno.:0097/TO/17,archivalnumber:DK-4100-84/17.

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[8] PodniałoA.:Paliwa, oleje i smary w ekologicznej eksploata-cji.WNT,Warszawa2002.

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[11] TOTAL–Smary plastyczne,rozdziałXIX,1-12;http://pro-dukty.totalpolska.pl/wiedza/rozdzial%2019.pdf(accesson:13.10.2017).

[12] TrzaskaE.:Smary litowe kompleksowe.BiuletynITN2001,no.4,pp.260–264.

artykuły


[13] TrzaskaE.,ŻółtyM.,SkibińskaA.:Badanie stabilności ter-mooksydacyjnej smarów plastycznych. Część 1 – smary na oleju o charakterze parafinowym.Nafta-Gaz2016,no.11,pp.984–991,DOI:10.18668/NG.2016.11.13.

[14] TrzaskaE.,ŻółtyM.,SkibińskaA.:Badanie stabilności termo-oksydacyjnej smarów plastycznych. Część 2 – smary na oleju o charakterze naftenowym.Nafta-Gaz2017,no.1,pp.49–53,DOI:10.18668/NG.2017.01.06.

[15] Żmudzińska-ŻurekB.(red.):Chemia i technologia ropy nafto-wej w laboratorium.WydawnictwoPolitechnikiKrakowskiej,1987.

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Legal and normative acts[17] ASTMD1478-11(2017)Standard Test Method for Low-Tem-

perature Torque of Ball Bearing Grease.[18] DIN51805-2:2016Prüfung von Schmierstoffen – Bestimmung

des Fließdruckes von Schmierfettenmitdem Verfahrennach Kesternich – Teil 2: Automatisches Verfahren.

[19] IP186:2015Determination of low-temperature torque of lu-bricating grease.

[20] JohnA.WaynickJ.A.:Patent4,859,352Low temperature High Performance Greases.Publikacja22.08.1989.

[21] NFT60629:2006Petroleum Products And Lubricants – low-temperature Torque of Ball Bearing Greases.

[22] PN-C-04146:1963Przetwory naftowe – Pomiar lepkości struk-turalnej smarów stałych.

[23] PN-C-96014:2014Środki smarowe – Smary plastyczne kla-sy K – Klasyfikacja i wymagania.

[24] PN-ISO12924:2012Środki smarowe, oleje przemysłowe i pro-dukty podobne (Klasa L) – Grupa X (Smary) – Wymagania.

[25] PN-ISO13737:2011Przetwory naftowe i środki smarowe – Po-miar penetracji smarów plastycznych w niskich temperaturach penetrometrem ze stożkiem.

[26] PN-ISO6743-9:2009 Środki smarowe, oleje przemysłowe i pro-dukty podobne (klasa L). Klasyfikacja. Part 9: Grupa X (Sma-ry plastyczne).

Eng.ElżbietaTRZASKAMSc.Head of the Asphalt Laboratory in the Oils, LubricantsandAsphaltDepartment.OilandGasInstitute–NationalResearchInstituteul.Lubicz25A31-503KrakówE-mail: [email protected]

Eng.AgnieszkaSkibińskaMSc.AssistantintheDepartmentofOils,LubricantsandAsphalt.OilandGasInstitute–NationalResearchInstituteul.Lubicz25A31-503KrakówE-mail: [email protected]

OFERTA

ZAKŁAD OLEJÓW, ŚRODKÓW SMAROWYCH I ASFALTÓWZakres działania: • opracowanie i modyfikacja technologii wytwarzania:

» olejów podstawowych (bazowych), » środków smarowych: olejów przemysłowych i smarów plastycznych, » wosków naftowych (parafin i mikrowosków), wosków i kompozycji specjalnych oraz

emulsji woskowych, » dodatków stosowanych podczas wydobycia i transportu ropy naftowej i gazu ziemne-

go: inhibitorów korozji, inhibitorów parafin, inhibitorów hydratów, inhibitorów hydra-tów i korozji, deemulgatorów oraz inhibitorów oporów przepływu ropy naftowej,

» asfaltów drogowych i przemysłowych, » olejów technologicznych do obróbki metali: emulgujących i nieemulgujących, » niskokrzepnących płynów do chłodnic samochodowych i spryskiwaczy samochodowych;

• specjalistyczne badania oraz ocena właściwości fizykochemicznych i użytkowych: » środków smarowych, smarów plastycznych i olejów przemysłowych, silnikowych, » wosków naftowych, wosków specjalnych oraz kompozycji i emulsji woskowych, » asfaltów drogowych przemysłowych oraz emulsji asfaltowych, roztworów i mas asfaltowych oraz innych specyfików asfalto-

wych;• opracowywanie zagadnień związanych z gospodarką olejami odpadowymi i odpadami rafineryjnymi;• sporządzanie ekobilansów procesów technologicznych metodą Oceny Cyklu Życia (LCA).

Kierownik: mgr inż. Stefan PtakAdres: ul. Łukasiewicza 1, 31-429 Kraków Telefon: 12 617 75 74Faks: 12 617 74 30, 12 617 75 22E-mail: [email protected]

doi: 10.18668/ng.2018.02.06 oil and gas institute ......din 51825 standard lubricants –...

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