Wet sliding friction of elastomer compounds on a rough surface under varied lubrication conditions

Wear262(2007)

707–717

Wet sliding friction of elastomer compounds on a rough

surface under varied lubrication conditions

Xiao-Dong Pan?

Bridgestone Americas Center for Research and Technology,1200Firestone Parkway,

Akron,OH44317-0001,United States

Received28February2006;received in revised form1August2006;accepted3August2006

Available online18September2006

Abstract

‘Green’tire bearing tread rubber reinforced with precipitated silica can exhibit improved wet traction performance.The underlying mechanism is currently not well understood.To improve our capability of rational material design for enhanced driving safety,wet sliding friction for various rubber compounds is tested on a Portland cement concrete surface under varied lubrication conditions.The wetting liquid is either ethanol or water,and the initial amount of liquid on the concrete surface is adjusted.Sliding friction is detected to alter with lubrication condition.Under ethanol lubrication,the sliding friction is markedly lower than that under water lubrication.Additionally the bene?t in wet traction from silica is signi?cantly diminished or eliminated in ethanol.Such observations cannot be rationalized with simple considerations of rubber bulk viscoelasticity, liquid viscosity,cavitation,or capillary effect.We believe that these observations strongly indicate the signi?cance of interfacial interactions in determining the wet sliding friction of elastomer compounds.The potential relevance of capillary porosity in concrete and Marangoni drying effect to wet traction is also introduced.

?2006Elsevier B.V.All rights reserved.

Keywords:Elastomer;Wet sliding;Friction;Silica;Water;Ethanol

1.Introduction

In order to stop a moving automobile on a highway wetted by rain,a maximal level of sliding friction from tires is obviously desired upon brake application.At low sliding speed before the emergence of elastohydrodynamic lubrication,other than the tread pattern,material properties of tread rubber compounds play a signi?cant role in determining the wet traction performance of a pneumatic tire.

Tread rubber compounds are made of crosslinked elastomers reinforced with?ne?ller particles.The conventional?ller has been carbon black derived from fossil fuel.Starting from the early1990s,precipitated silica used along with silane has become popular in preparing the so-called‘green’tire[1].In comparison to carbon black-?lled rubber,silica-reinforced rub-ber can lead to simultaneous reduction in fuel consumption and enhancement in wet grip while maintaining wear resis-?Tel.:+13303797339;fax:+13303797530.

E-mail address:panxiaodong@https://www.sodocs.net/doc/031627142.html,.tance.Such unexpected gain in the combination of performance

characteristics has spurred renewed interests in fundamental

understanding on mechanisms of wet sliding friction.

For tribological systems consisting of rubber sliding on a

rough road surface with water in-between,factors affecting the friction characteristics have been recognized[2–4].During slid-

ing,the multi-scale asperities on road surface induce high fre-

quency dynamic deformation of rubber.Viscoelastic dissipation

of energy inside rubber is considered as the primary contributor

to sliding friction[5].Coef?cient of frictionμdepends on the

so-called reduced variable a T·v.Here the temperature dependent a T is the well-known Williams–Landel–Ferry time–temperature

shifting factor[6]while v is the sliding speed.In comparison,the

load exerts much less sensitive impact on friction[4].Quantita-

tive analysis of rubber friction certainly requires proper account

of the typically nonlinear viscoelasticity for rubber compounds,

the speci?c roughness characters for the road surface,as well

as effects from friction heating at high v.Though not yet well

explained,testing of‘veneered’rubber compounds indicates the

importance of the thin surface layer of rubber in determining wet

sliding friction[7,8].

0043-1648/$–see front matter?2006Elsevier B.V.All rights reserved. doi:10.1016/j.wear.2006.08.003

708X.-D.Pan/Wear262(2007)707–717

Without interference from surface charge[4],remaining contribution from adhesion(or adhesion hysteresis[9–11])is detectable(embodied as the presence of a hump along a friction master curve).Possible impact from the chemical nature of road surface has rarely been assessed[3].In the presence of sharp surface asperities,tearing of rubber can further enhance friction [12].Even though intuitive concern on possible change in rhe-ological behavior of extremely thin water?lm was raised[13], viscous dissipation within the remaining water?lm is generally considered insigni?cant.

Some detailed studies have been performed for the case of smooth rubber on a wet smooth glass surface.Summarizing variation of friction with dynamic lubrication conditions,some Stribeck curves were established[14].The?ne details of extru-sion of liquid between the rubber and the glass surface were examined with the method of optical interferometry[15].Under proper conditions during sliding,waves of rubber detachment (Schallamach waves)were observed[16].Under both non-sliding and sliding conditions,the process of interfacial energy-driven dewetting has also been studied[17–20],including the situation where there exists single defect on the glass surface.

A smooth glass surface is certainly much less complicated than a realistic highway surface.Other than the multi-scale asperities on the road surface,a piece of typical Portland cement concrete can have porosity of10–20%[21].Thus the road sur-face can be leaky.Even though possible implications of capillary porosity to liquid extrusion,viscous energy dissipation,and rewetting of surface are completely ignored in recent literature, there is an earlier investigation of dynamic permeability of pave-ments[22].

Facing such multitude of factors,the dif?culty in predicting the likely level of friction of rubber components in engineering practice has been realized[23].Recently,quantitative modeling of rubber friction on a fractal surface has been presented based on bulk viscoelastic description of material behavior[24,25]. Among the many proposals attempting to rationalize the bene?t in wet traction from silica,the existence of a softer skin at the sliding interface for silica-?lled rubber appears plausible[26]. The stress-softening effect can be stronger for silica-?lled rubber than that for carbon black-?lled rubber.However,practitioners also reported discrete singular observation that the bene?t in wet traction from silica disappears on a surface lubricated with ethanol[27].

Obviously establishing a complete set of phenomenology is essential for achieving a true understanding on friction mecha-nisms,which is the main purpose for this study.Here wet sliding friction for various rubber compounds is tested under different lubrication conditions with a portable British Pendulum Skid Tester(BPST)[28,29].A Portland cement concrete patio block provides the road surface.The concrete surface is wetted with either ethanol or water.Due to the current absence of ef?cient method for accurate quanti?cation of water?lm thickness on a rough surface,the lubrication condition is further adjusted by generating visually different amount of liquid on the surface before any sliding test.

With the BPST,a rubber slider attached to the end of the swinging arm slides on the road surface for a?xed length of path.During sliding,kinetic energy of the swinging arm is con-sumed to overcome the sliding friction.Consequently after the slider comes off contact with the road surface,the initial releas-ing height of the arm cannot be regained.The instrument reading, British Pendulum(Tester)Number or BPN,corresponds to such lost in height and hence indicates the level of sliding friction. Approximately BPN is of order of100×μ,hereμis the coef-?cient of friction[30].Hence it is more sensitive to use BPN to display the variation of friction with lubrication condition.

It is dif?cult to quantify the dynamic contact condition for BPST.However,effects from a variety of factors on wet skid resistance of rubber compounds have been revealed with BPST [30–34].The designed average contact pressure during sliding for BPST is of order of0.21MPa[28],similar to the nominal pressure between a passenger tire and road.However,the local contact pressure between rubber and sharp surface asperities can reach well beyond10MPa[35].The rubber slider moves at about 2.7m/s(or9.7km/h)when it?rst makes contact with the surface. At such sliding speed,the shear rate in a thin water?lm of1nm thickness on a smooth surface is of order of109s?1.The relax-ation rate of bulk water molecules is of order of1012s?1[36].

The lubrication behavior of extremely thin liquid?lms con-?ned between molecularly smooth surfaces has been quan-titatively examined with various Surface Force Apparatuses (SFA)[37–39].The contact pressure encountered in SFA can be3–5MPa[36].Current experimental evidences indicate that when con?ned between hydrophilic surfaces,the?uidity and lubricity of water remains down to one single layer of molecules [40,41].With a different experimental technique,ordering of liquid alkanes con?ned between an elastomer and a sapphire substrate has recently been reported[42].

Examination of sliding friction under ethanol lubrication is also important for other reasons.As displayed in Fig.1,rapid formation of a‘dry’patch can be induced by dropping a small bead of ethanol onto water residing on top of the concrete sur-face.This arises from the signi?cant difference in surface tension between the two liquids.At20?C,the surface tension is22.3 and72.8mN/m for ethanol and water,respectively[43].Can such Marangoni drying effect[44,45]be applied to improve tire wet traction performance?Such expectation may be

further Fig.1.Marangoni drying on the water-covered concrete surface caused by a drop of ethanol(diameter～2mm).

X.-D.Pan/Wear262(2007)707–717709

enhanced by the following observation[3,14].For a smooth rubber sliding(at small v)on a wet smooth glass surface,in the boundary lubrication regime,the friction under alcohol lubri-cation is higher than that under water lubrication.This was attributed to the absorption of alcohol into the rubber.A larger contact area was resulted from the softened swollen rubber.For paraf?n alcohols of varied hydrocarbon chain length,friction maximize at octanol.In contrast,on a Perspex(polymethyl-methacrylate)surface,ethanol becomes a better lubricant[46].

2.Experimental methods

2.1.Materials

Even though rubber compounds prepared with elastomers exhibiting quite different glass transition temperature T g have been tested,in this report we focus primarily on results obtained for four compounds made of a tin-coupled styrene–butadiene rubber(SBR,random copolymer)with T g at?29.5?C(Duradene739from Firestone Polymers).Here the midpoint T g is identi?ed via the differential scanning calorime-try(DSC)characterization at the heating rate of10?C/min.The microstructure of polymer molecules was revealed with nuclear magnetic resonance(NMR)test:21.0%bound styrene(by weight),47.3%1,2-butadiene content,and31.7%1,4-butadiene content.The gel permeation chromatography(GPC)tests indi-cated a weight-average molecular weight of411.9×103g/mol, a polydispersity index of1.59,and a total coupling of60.3% including a thermal coupling of11.8%.

The four compounds include a gum compound containing no ?ller,a carbon black-?lled compound,a silica-?lled compound prepared in the absence of silane,and a silica-?lled compound prepared in the presence of silane Si69.In the following they are denoted as SBR-G,SBR-C,SBR-SiO2,and SBR-SiO2-Si69, respectively.The compounding formula is shown in Table1. The?lled compounds contain50phr(part per hundred rubber, by weight)of?ller.

Carbon black of grade N339was used in SBR-C while amorphous precipitated silica(Hi-sil190G from PPG Indus-tries)was used in the silica-?lled compounds.The typical pri-mary particle size according to electron microscopy is between 26and30nm for N339,and is averaged at17nm for Hi-Sil 190G.The nitrogen-adsorption surface area(according to the Brunauer–Emmett–Teller equation)for N339and Hi-Sil190G is96and215m2/g,respectively.

In preparing SBR-SiO2-Si69,5phr of liquid organosilane bis(3-triethoxysilylpropyl)tetrasulfane(Si69from Degussa)was added during remill.In the absence of silane,to compensate for potential loss of sulfur due to its adsorption onto silica surface, a larger amount of sulfur was incorporated into SBR-SiO2to achieve a suf?cient level of crosslinking.This,in addition to the strong inter-particle hydrogen bonding(arising from hydroxyl groups on silica surface),makes SBR-SiO2the hardest com-pound.Considering the essential difference in surface chemistry between carbon black and silica,as well as the role of coupling from the silane Si69,the bonding between matrix polymer and ?ller particle surface is very different among the three?lled compounds.

Some typical characteristics for the four compounds are listed in Table2.The tensile testing was performed with a model4501 Instron Universal Testing Instrument.Viscoelastic behavior for the compounds was examined with two Advanced Rheomet-ric Expansion Systems(from Rheometric Scienti?c)[34].To examine the extent of absorption of ethanol into the rubber com-pounds,for each compound,four rectangular specimens were immersed into ethanol.Each specimen was about1.9mm thick and weighted about1.0g.The ethanol was replaced after24h of immersion.The wet weight was obtained for two specimens after72h of immersion and for the other two specimens after 144h of immersion.Each specimen was subsequently dried for24h in a vacuum oven heated to about60?C and its dry weight was acquired.The total swelling is calculated as the dif-ference in wet weight and dry weight normalized by the dry weight.

Table1

Compounding formulas

Mixing stage In phr SBR-G SBR-C SBR-SiO2SBR-SiO2-Si69 Master batch SBR100100100100

Carbon black05000

Silica005050

Stearic acid2222

6PPD a1111

Remill Si69b N/A005

Final batch Zinc oxide3333

DPG c0.50.50.70.7

MBTS c1111

TBBS c0011

Sulfur 1.3 1.3 3.0 1.15

Total108.8158.8161.7164.85

a The antidegradant6PPD is N-(1,3-dimethylbutyl)-N -phenyl-p-phenylenediamine.

b The bifunctional,sulfur-containing organosilane Si69is bis(triethoxysilylpropyl)tetrasulfane.

c The vulcanization accelerators DPG,MBTS,an

d TBBS represent diphenyl guanidine,dibenzothiazyl disul?de,and N-tert-butyl-2-benzothiazyl sulfenamide, respectively.

710X.-D.Pan/Wear262(2007)707–717

Table2

General characteristics for the cured compounds

SBR-G SBR-C SBR-SiO2SBR-SiO2-Si69 Filler volume fraction a(%)0.019.717.917.4

Midpoint T g(?C)?25.8?24.7?21.6?24.7 Temperature at peak tanδb(?C)?16.0?16.0?14.0?16.0 Tensile test at RT Strain rate during testing at0.282s?1

Stress at break(MPa) 1.9322.116.620.1

Strain at break(%)381.2437.3325.6424.7

Stress at200%strain(MPa) 1.147.729.887.52

Modulus at200%strain(MPa)0.350 5.18 5.02 4.33 Dynamic strain sweep test c Tested at1Hz,values below taken at the strain amplitude of11.8%

(1)At RT

(1.1)G at RT(MPa)0.627/0.643 2.52/2.56 5.38/5.43 2.68/2.79

(1.2)tanδat RT0.0720/0.07250.141/0.1440.190/0.1880.153/0.156

(2)Temperature d?C?14.2?13.4?11.1?13.0

(2.1)G (MPa) 3.86/4.1012.6/12.920.3/21.112.5/12.9

(2.2)tanδ 1.82/1.83 1.32/1.32 1.11/1.11 1.33/1.31

(3)Temperature e(?C)?14.7?14.0?11.7?13.5

(3.1)G (MPa) 4.0313.419.712.7

(3.2)tanδ 1.88 1.36 1.21 1.40

(4)At?14.2?C f

(4.1)G (MPa) 3.57/3.8013.523.413.3

(4.2)tanδ 1.81/1.78 1.37 1.30 1.44

Total swelling g(wt.%)Sample weight～1.0g,thickness～1.9mm

(1)After72h in ethanol 2.73 1.83 2.78 2.37

(2)After144h in ethanol 3.50 2.28 3.10 3.26

a Calculated according to the formula in Table1,taking1.8and2.0g/cm3as the density for carbon black and silica,respectively.

b From dynami

c temperature step test at1Hz with the strain amplitude at0.20%.

c Two samples teste

d under som

e conditions to check reproducibility.

d Determined via th

e method o

f time–temperature shifting,correspondin

g to BPST testing at20.9?C[34].

e Corresponding to BPST testing at19.2?C for demonstration o

f sensitivity.

f Tested after completion of all previous dynamic strain sweep tests.

g Two rectangular samples tested for each compound.

By itself,the rubber grade carbon black is hydrophobic while the precipitated silica is hydrophilic.The matrix elastomer is hydrophobic while the concrete surface is hydrophilic.The silanized silica becomes hydrophobic and thus compatible with the matrix elastomer.Both the rubber compound surface and the road surface are physicochemically heterogeneous.

2.2.Testing of wet sliding friction

Results reported here were obtained under ambient condi-tions with the room temperature(RT)in the range between23.0 and24.8?C.To remove possible residual mold release agent, the sliding edge of the rubber sliders was wiped with acetone at least1h before testing.BPST testing was performed for all the compounds in ethanol(anhydrous from AAPER)?rst.With-out being moved,the concrete block went through air-drying and extensive washing with water before further BPST testing under water lubrication.De-ionized water was then added for testing of wet sliding friction.Videos and pictures related to BPST testing were recorded with a digital camera(Canon Pow-erShot A620).For each compound,two sliders were tested under ethanol lubrication and two different sliders were tested under water lubrication.

The concrete block has the dimensions of approximately 20.2cm×20.3cm×4.4cm.By examining the difference in weight between the wet block soaked with water and the block after thorough air-drying,the volume fraction of capillary porosity is estimated to be12.6%.Prior to this study,the testing surface has been exposed to a substantial amount of testing of wet friction.

As displayed in Fig.2,the varied lubrication conditions investigated consist of the visually different initial amount of liquid present on the concrete surface before any sliding test. Corresponding to Fig.2a–c,in the following,these different lubrication conditions are referred to as Condition A,Condition B,and Condition C,respectively.A large portion of the con-crete body is immersed in the liquid.To avoid accumulation of possible wear debris of rubber on the testing surface,the sur-face was refreshed in the presence of suf?cient amount of liquid with a brush bearing soft stainless steel hair.The diameter of an individual bristle is about120?m.Unless otherwise noted,such surface agitation was consistently applied before every sliding test and the hair did become gradually worn away from brushing.

Concerning Condition A,the relatively thick layer of liquid on the surface was formed by adding extra liquid after brushing. Previous BPST testing reported was all performed under this

X.-D.Pan/Wear262(2007)707–717

711

Fig.2.Different wet state of the concrete surface before friction testing.(a)Con-dition A:covered with a relatively thick layer of water.(b)Condition B:covered with a relatively thin layer of water.(c)Condition C:only the residual amount of water remaining.(d)Almost dried after overnight air-drying as a comparison.condition[32–34]for closer simulation of realistic concern.The obviously thinner layer of liquid on the surface for Condition B was formed by gently brushing off the extra liquid from the surface.After one sliding test under Condition B,a few sliding tests were performed consecutively without any other action to the surface.Such surface state corresponds to Condition C.For comparison purpose,a partially dried surface after air-drying for overnight is shown in Fig.2d.

3.Results and discussion

Under an imposed sinusoidal deformation of small amplitude at the frequency of f0,the variation of elastic modulus G and loss tangent tanδwith temperature T was measured(Fig.3a).Loss tangent,characterizing the viscoelastic loss property,exhibits a distinct peak at the center of the transitional zone between the glassy state and the rubbery state.The temperature at the peak of tanδ,T Peak tanδ,varies with f0.Wet sliding friction for compounds very similar to SBR-G and SBR-C were previously tested for0

When the rubber slider slides across the surface bearing dif-ferent initial amount of water,the extent of water splashing is obviously different(Fig.4).Under Condition A,after the rubber slider leaves the surface,the patch swept out by the rubber

slider Fig.3.Similarity in temperature dependency between bulk viscoelastic loss and wet sliding friction.(a)Variation of the elastic modulus G and the loss tangent tanδwith temperature.These are obtained under an imposed sinusoidal strain at the frequency of f0=0.01Hz and with the strain amplitude at0.20%.The temperature at the peak of tanδ,T Peak tanδ,is?23.3and?23.0?C for SBR-G and SBR-C,respectively.(b)Variation of BPN with temperature reported previously for similar compounds[32].Reinforcing carbon black of different grade(N339vs.N121)was employed for preparing SBR-C in the two plots.

712X.-D.Pan/Wear262(2007)707–717

Fig.4.The rubber slider(for SBR-C)striking the concrete surface during the

pendulum skid testing.(a)A schematic plot of the portion of the pendulum

swinging arm bearing the rubber slider.(b)Corresponding to Fig.2a.(c)Cor-

responding to Fig.2b.(d)Corresponding to Fig.2c.

Fig.5.Rewetting of the patch on the concrete surface swept out by the rubber

slider(for SBR-C).The starting condition is that shown in Fig.2a.(a)Right

after the slider comes off contact with the concrete.(b)A short moment later.

(c)The shrinking‘dry’patch.(d)Complete disappearance of the‘dry’patch.

The time interval from(a)to(c)is about1s.The‘dry’patch almost completely

disappeared in2s from(a).

X.-D.Pan/Wear262(2007)707–717

713

Fig.6.Wet sliding friction detected under varied lubrication conditions.(a)For the gum compound with the surface wetted with either water or ethanol.(b)For all the reinforced compounds with the surface wetted with water.(c)For all the reinforced compounds with the surface wetted with ethanol.

becomes quickly rewetted in just a few seconds(Fig.5).After repeated testing under Condition C,the surface remains visu-ally wet.Discussion on the?ne difference between wet and dry surface was made long ago[47].It was noted that even a‘dry’surface may still be covered with adsorbed water up to the limit of invisibility at about500?A.The possibility of boiling away of such thin water?lm from friction heating at large sliding speed was recognized.

In Fig.6,the time sequence of BPN collected for each com-pound under varied lubrication conditions is displayed.Here two samples were tested for each compound with good reproducibil-ity.The?rst12and the?nal4sliding tests were performed under Condition A.In between there were four sliding tests under Con-dition B and four sliding tests under Condition C.For testing under Condition C,the time interval between two consecutive tests was about8s.

Even though it is not dramatic,the impact on sliding friction from the initial amount of liquid on the concrete surface is always detected.It has been pointed out that at low sliding speed(less than about30km/h)the hydrodynamic buildup of liquid between rubber and road surface is negligible[48].However,we hope that the detected variation can offer clues to the understanding of energy dissipation mechanisms during wet sliding.

When the lubricating liquid is changed from water to ethanol, however,the sliding friction becomes markedly reduced for all the compounds.Consequently,the attempt to enhance friction under water lubrication via the Marangoni drying effect is unsuc-cessful.The sliding edge for the slider was smeared with a paper towel soaked with ethanol or the more absorbing acetone.No increase in BPN was observed under Condition A.In fact,small negative impact was observed.

If considering that ethanol may be absorbed into the com-pound and results in a softened compound,the observed reduced friction is just opposite to such reasoning.In fact,after immer-sion in ethanol for over144h,the absorption of ethanol into the compounds is most for SBR-G at3.5%by weight(Table2).

Other compounds prepared with polymers of widely different T g(≤?29?C,not including butyl rubber)were also tested under ethanol lubrication.Under ambient testing condition,BPN in water increases with increasing T g.Such a trend is retained in ethanol.

During BPST testing the system is in a highly non-equilibrium state.The constant agitation to the liquid during testing increases evaporation of liquid and consequently grad-ually lowers the liquid temperature.For one series of testing under water lubrication,RT was between24.1and24.8?C, the initial water temperature was at22.6?C.After over2h of testing,temperature for water surrounding the concrete block became20.0?C.In contrast,for one series of testing under ethanol lubrication,RT was between23.4and23.5?C,the initial ethanol temperature was at20.4?C.After about2h of testing,the ethanol temperature became15.0?C.Temperature on the con-crete surface may be even lower.Under water lubrication,BPN for compounds made of a low-cis polybutadiene(T g=?90.4?C) increases gradually with decreasing T[33].However,BPN for such compounds still becomes markedly lower when tested in ethanol under ambient condition.Thus the reduced friction from ethanol lubrication is unlikely explained from bulk viscoelastic consideration.

The viscosity of water is1002and1793?Pa s at20and 0?C,respectively.The viscosity of ethanol is1201,1317and 1786?Pa s at19.2,14.5and0?C,respectively[49].As dis-played in Fig.3b for the compound SBR-G,when T is decreased from20to about0?C,the wet sliding friction is only reduced by about5BPN units.Thus the reduction of about10BPN units in sliding friction for SBR-G under ethanol lubrication cannot come from the higher ethanol viscosity under the testing condi-tions employed.

For consideration of possible cavitation based on the simplis-tic conventional criterion,the vapor pressure for water is2.34and 6.63kPa at20and38?C,respectively.The vapor pressure for ethanol is5.81and4.27kPa at20and15?C,respectively.Under water lubrication,when T is increased from20to about40?C, BPN for the compound very similar to SBR-C remains essen-tially unchanged(Fig.3b).As reported earlier[33],the bene?t in wet traction from silica under water lubrication persists in the same temperature range.Therefore,the vapor pressure at15?C

714X.-D.Pan/Wear262(2007)707–717

for ethanol cannot explain the signi?cantly reduced sliding fric-tion under ethanol lubrication.

Under the lubrication of the same initial amount of water (Fig.6b),the sliding friction for both silica-?lled compounds is markedly higher than that for the carbon black-?lled compound. Even comparing across testing under the lubrication of different initial amount of water on the concrete surface,on average,BPN for SBR-C under Condition B is still lower than BPN for SBR-SiO2and SBR-SiO2-Si69under Condition A by1.5and3.8, respectively.In contrast,under the lubrication of the same initial amount of ethanol(Fig.6c),the enhancement in wet sliding friction from silica is much reduced for SBR-SiO2-Si69and eliminated for the harder SBR-SiO2.

From tensile testing at RT(Table2),the modulus at200% strain for SBR-C is higher than that for SBR-SiO2-Si69.This is partially due to the fact that the density for silica is slightly higher than that for carbon black,thus at the same?ller loading of50phr(by weight),the actual volume fraction of?ller is lower for SBR-SiO2-Si69.A compound was prepared with the same SBR,in the presence of Si69,but with the amount of silica increased to match the?ller volume fraction for SBR-C.The modulus at200%strain for this compound is higher than that for SBR-C.Under water lubrication,BPN for this compound under Condition A is slightly lower than BPN for SBR-SiO2-Si69under Condition A(by1.1),but still markedly higher than BPN for SBR-C under Condition B(by2.7).

Comparing SBR-SiO2to SBR-SiO2-Si69,there exists obvi-ous difference in modulus(Table2),some quantitative difference in wet sliding friction is also detected(Fig.6).This indicates that for compounds?lled with the same kind of?ller,change in viscoelastic characters is expected to result in corresponding variation in wet sliding friction.Values of the conventional vis-coelastic predictor for wet traction,tanδ,are listed in Table2 for all the compounds.The dynamic strain sweep tests were performed at1Hz and at low temperature determined with the method of time–temperature shifting,assuming that the domi-nant frequency of material deformation during BPST testing is at104Hz[34].Value of tanδis somewhat arbitrarily taken at the speci?c strain amplitude of11.8%for all the compounds.From Table2,the predictor from bulk viscoelastic measurement can-not account for the difference in wet sliding friction under water lubrication that arises from the usage of different?ller particles.

After completion of the testing displayed in Fig.6,the wear scar at the sliding edge of the rubber sliders was examined under a stereo optical microscope.Pictures of the wear scar are shown in Fig.7for all the compounds.Clearly,the wear scar on the sliders tested under ethanol lubrication is less severe than that on the corresponding sliders tested under water lubrication.Thus the lower wet sliding friction detected under ethanol lubrication is accompanied with a less severe wear at the sliding edge of the slider.

Based on the discussions above,the eliminated bene?t in wet traction from silica under ethanol lubrication cannot be explained with simple considerations of liquid viscosity,cav-itation,capillary effect,or rubber bulk viscoelasticity.However, such effect from ethanol lubrication does resemble strongly fea-tures of interfacial interactions in a liquid medium

revealed Fig.7.Wear scar at the tested edge for the rubber sliders subjected to the testing displayed in Fig.6.Relative to the slider,the road surface moves along the arrow direction.The division on the ruler indicates1mm.

X.-D.Pan/Wear262(2007)707–717715

with an atomic force microscope(in the absence of sliding) [50,51].Related to hydrophobic interactions,when a substantial amount of ethanol is mixed into water,the attraction between hydrophobic self-assembled monolayers becomes signi?cantly weakened[50].Even though no explicit data were given con-cerning adhesion hysteresis,the simultaneous signi?cant reduc-tion in both jump-in distance and pull-off force should indicate reduced adhesion hysteresis.In the case of a hydrophobic mono-layer interacting with a hydrophilic monolayer[51],both the pull-off distance and the pull-off force reduces signi?cantly with increasing amount of ethanol in the mixture of water and ethanol.

From such similarity in phenomenology,it becomes appar-ent that in addition to bulk hysteretic loss in rubber,interfacial interactions across the sliding interface can also be a signi?-cant contributor to wet friction on a rough road surface.The different extent of reduction in BPN under ethanol lubrication exhibited by different compounds may re?ect the difference in relative proportion of the two friction contributors for each compound.

Prior to each testing of wet friction under Conditions A and B, a brush bearing stainless steel hair was employed to refresh the concrete surface in the presence of suf?cient amount of liquid. The brush hair does wear away and some of the stainless steel wear particles do deposit onto the concrete surface.It is reason-able to be concerned on the potential in?uence of such stainless steel wear particles on the interfacial interactions between a rub-ber slider and the concrete surface.To address such concern, sliders of SBR-C and SBR-SiO2-Si69were tested under water lubrication on a fresh concrete surface without any prior his-tory of being brushed.Under Condition A,in the absence of brushing,BPN exhibited more variation with time,especially at the beginning.However,the difference in BPN between SBR-C and SBR-SiO2-Si69persists.On the other hand,refreshing the surface via brushing does lead to a much stabilized BPN reading.

Practitioners have attempted to separate adhesion and hys-teretic contributions to sliding friction of elastomers[52,53]. This study may suggest that adhesion is substantially reduced under ethanol lubrication.For many people working in the rub-ber industry,adhesive friction(under dry conditions)is strongly associated with the image of breakup and reformation of bonds across the interface[54,55].On the other hand,it is obvious from modern studies on intermolecular interactions that even separated with tens layers of water molecules,under proper con-ditions,signi?cant attractive interactions are present[40].Thus direct contact is probably not a prerequisite for the relevance of adhesion to wet friction.

The diameter of water molecules is about2.5?A[40].The thickness of20layers of water molecules is about5nm.The typical primary particle size for?ller is above10nm while an individual?ller particle consists of tens of primary particles fused together.It is thus clear that for consideration of interfacial interactions between?ller particles and the road surface across a molecularly thin layer of water,the continuum viscoelastic description of bulk material behavior is not of direct relevance. On the other hand,it has been pointed out not long ago that poly-mer viscoelasticity is not the prerequisite for the appearance of the bell-shaped variation of friction with temperature or slid-ing speed[56].It has been detected from microscopic friction characterization for non-polymeric systems.

Considering that both the original silica particles and the Port-land cement concrete surface are hydrophilic,the enhanced wet traction from silica does not necessarily come from hydropho-bic interactions.However,if the phenomenon of strong attractive hydrophobic interactions in water,with improved mechanistic understanding[57,58],can be appropriately controlled,it may be a factor to consider for enhancing wet traction.In water the exis-tence of an extremely thin layer of gas phase at a hydrophobic surface has been discussed[59,60].It is unclear how interfa-cial interactions between the hydrophobic rubber surface and the hydrophilic concrete surface in relative motion are affected by the state of water con?ned in-between.

Putting into consideration the complete set of phenomenol-ogy and contemplating from the right perspective,it is possible to achieve a coherent understanding on friction mechanisms suf-?cient for rational material design.This shall open the door for further enhancing tire wet traction performance and more impor-tantly the safety of the driving public.

4.Summary

Wet sliding friction of various elastomer compounds on a rough Portland cement concrete surface is examined under different lubrication conditions.The lubrication condition is adjusted via varying the initial amount of liquid–ethanol or water present on the surface.While the surface remains visually wet under all testing conditions examined,wet sliding friction is detected to vary with the lubrication condition.Overall wet friction becomes markedly reduced under ethanol lubrication in comparison to that under water lubrication.This is accompanied with a less severe wear scar at the tested edge of rubber sliders under ethanol lubrication.In comparison to a carbon black-?lled compound,silica-reinforced compounds exhibit higher wet sliding friction in water.However,such effect from silica is eliminated in ethanol.These observations resemble features of interfacial interactions revealed from investigations employing AFM(in the absence of sliding),hence strongly indicate that in addition to bulk viscoelastic hysteresis,interfacial interactions between?ller particles and the road surface are also a signi?cant contributor to wet sliding friction of elastomer compounds on a rough surface.Contribution to wet friction from such interfacial interactions may exhibit temperature dependency different from that corresponding to the contribution from bulk viscoelastic-ity.The potential relevance of capillary porosity in concrete and Marangoni drying effect to wet traction is also introduced.More quantitative studies will undoubtedly result in our improved capability of rational material design for further enhanced public driving safety.

Acknowledgements

The permission of Bridgestone/Firestone North American Tire,LLC to publish this work is much appreciated.I thank M.W. Hayes for DSC and GPC tests;D.R.Brumbaugh for NMR test;

716X.-D.Pan/Wear262(2007)707–717

J.Anson for tensile test;J.N.Israelachvili,J.Klein and H.A. Stone for literature.

References

[1]S.Wolff,U.G¨o rl,M.-J.Wang,W.Wolff,Silica-based tread compounds,

Eur.Rubber J.176(1994)16–19.

[2]A.Schallamach,K.Grosch,Tire traction and wear,in:S.K.Clark(Ed.),

Mechanics of Pneumatic Tires,U.S.Department of Transportation,Wash-ington,DC,1981,pp.365–474.

[3]A.D.Roberts,A guide to estimating the friction of rubber,Rubber Chem.

Technol.65(1992)673–686.

[4]K.A.Grosch,The rolling resistance,wear and traction properties of tread

compounds,Rubber Chem.Technol.69(1996)495–568.

[5]K.A.Grosch,Relation between the friction and visco-elastic properties of

rubber,Nature197(1963)858–859.

[6]J.D.Ferry,Viscoelastic Properties of Polymers,third ed.,John Wiley&

Sons,New York,1980.

[7]T.French,R.G.Patton,Advances in roadholding characteristics of car

tyres,in:T.H.Messenger(Ed.),Proceedings of the Fourth Rubber Tech-nology Conference,Institution of the Rubber Industry,London,1963, pp.196–216.

[8]E.P.Percarpio,E.M.Bevilacqua,Lubricated friction of https://www.sodocs.net/doc/031627142.html,-

ponents of friction in mating surfaces,Rubber Chem.Technol.41(1968) 854–861.

[9]A.D.Roberts,A.G.Thomas,The adhesion and friction of smooth rubber

surfaces,Wear33(1975)45–64.

[10]K.Kendall,Rolling friction and adhesion between smooth solids,Wear33

(1975)351–358.

[11]H.Yoshizawa,Y.-L.Chen,J.N.Israelachvili,Fundamental mechanisms

of interfacial friction.I.Relation between adhesion and friction,J.Phys.

Chem.97(1993)4128–4140.

[12]J.A.Greenwood,D.Tabor,The friction of hard sliders on lubricated rubber:

the importance of deformation losses,Proc.Phys.Soc.(Lond.)71(1958) 989–1001.

[13]A.D.Roberts,in:D.F.Hays,A.L.Browne(Eds.),The Physics of Tire

Traction,Plenum,New York,1974,p.214.

[14]S.C.Richards,A.D.Roberts,Lubrication of rubber by aqueous and non-

aqueous liquids,J.Nat.Rubber Res.3(1988)210–222.

[15]A.D.Roberts,D.Tabor,The extrusion of liquids between highly elastic

solids,Proc.R.Soc.Lond.A325(1971)323–345.

[16]A.D.Roberts,Rubber friction:‘wet’Schallamach waves,J.Nat.Rubber

Res.4(1989)166–178.

[17]F.Brochard-Wyart,P.-G.de Gennes,Dewetting of a water?lm between a

solid and a rubber,J.Phys.Condens.Mater.6(1994)A9–A12.

[18]A.Martin,A.Buguin,F.Brochard-Wyart,Dewetting nucleation centers at

soft interfaces,Langmuir17(2001)6553–6559.

[19]A.Martin,J.Clain,A.Buguin,F.Brochard-Wyart,Wetting transitions at

soft,sliding interfaces,Phys.Rev.E65(2002)031605.

[20]G.Carbone,B.N.J.Persson,Dewetting at soft viscoelastic interfaces,J.

Chem.Phys.121(2004)2246–2252.

[21]C.P.Vernet,Ultra-durable concretes:structure at the micro-and nanoscale,

MRS Bull.29(2004)324–327.

[22]J.W.Hutchinson,T.Y.Kao,L.C.Pendley,Pavement dynamic permeability

testing,in:Highway Skid Resistance,Special Technical Publication No.

456,American Society for Testing and Materials,Philadelphia,1969,pp.

159–176.

[23]S.P.Arnold,A.D.Roberts,A.D.Taylor,Rubber friction dependence on

roughness and surface energy,J.Nat.Rubber Res.2(1987)1–14. [24]B.N.J.Persson,U.Tartaglino,O.Albohr,E.Tosatti,Sealing is at the origin

of rubber slipping on wet roads,Nat.Mater.3(2004)882–885.

[25]A.Le Gal,X.Yang,M.Kl¨u ppel,Evaluation of sliding friction and contact

mechanics of elastomers based on dynamic–mechanical analysis,J.Chem.

Phys.123(2005)014704.

[26]D.M.Dryden,J.R.Luchini,G.B.Ouyang,Trends in tyre technology,in:

S.K.De,J.R.White(Eds.),Rubber Technologist’s Handbook,Rapra Tech-nology,Shawbury,2001,pp.351–400.[27]T.Fujimaki,K.Morita,Recent patents on silica reinforced polymers,Int.

Polym.Sci.Technol.26(1999)26–34.

[28]C.G.Giles,B.E.Sabey,K.H.F.Cardew,Development and performance

of the portable skid resistance tester,in:Symposium on Skid Resistance, Special Technical Publication No.326,American Society for Testing and Materials,Philadelphia,1962,pp.50–74.

[29]E.M.Bevilacqua,E.P.Percarpio,Friction of rubber on wet surfaces,Science

160(1968)959–964.

[30]B.E.Sabey,G.N.Lupton,Friction on wet surfaces of tire-tread-type vul-

canizates,Rubber Chem.Technol.37(1964)878–893.

[31]S.Kawakami,M.Misawa,H.Hirakawa,The relation between temperature

dependence of viscoelasticity and friction due to hysteresis,Rubber World 198(1988)30–38.

[32]X.-D.Pan,Relationship between the dynamic softening transition and wet

sliding friction of elastomer compounds,J.Polym.Sci.,Part B:Polym.

Phys.42(2004)2467–2478.

[33]X.-D.Pan,Impact of reinforcing?ller on the dynamic moduli of elastomer

compounds under shear deformation in relation to wet sliding friction, Rheol.Acta44(2005)379–395.

[34]X.-D.Pan,Signi?cance of tuning bulk viscoelasticity via polymer molec-

ular design on wet sliding friction of elastomer compounds,Tribol.Lett.

20(2005)209–219.

[35]C.G.Giles,B.E.Sabey,The effect of pressure and friction on photographic

emulsions,Br.J.Appl.Phys.2(1951)174.

[36]Y.Zhu,S.Granick,Viscosity of interfacial water,Phys.Rev.Lett.87(2001)

096104.

[37]J.N.Israelachvili,P.M.McGuiggan,A.M.Homola,Dynamic properties of

molecularly thin liquid?lms,Science240(1988)189–191.

[38]S.Granick,Motions and relaxations of con?ned liquids,Science253(1991)

1374–1379.

[39]J.Klein,E.Kumacheva,Con?nement-induced phase transitions in simple

liquids,Science269(1995)816–819.

[40]J.N.Israelachvili, A.D.Berman,Surface forces and microrheology

of molecularly thin liquid?lms,in:B.Bhushan(Ed.),Handbook of Micro/Nano Tribology,second ed.,CRC Press,Boca Raton,1999,pp.

371–432.

[41]U.Raviv,https://www.sodocs.net/doc/031627142.html,urat,J.Klein,Fluidity of water con?ned to subnanometer

?lms,Nature413(2001)51–54.

[42]K.Nanjundiah,A.Dhinojwala,Con?nement-induced ordering of alka-

nes between an elastomer and a solid surface,Phys.Rev.Lett.95(2005) 154301.

[43]D.R.Lide,CRC Handbook of Chemistry and Physics,79th ed.,CRC Press,

Boca Raton,1998.

[44]A.B.Afsar-Siddiqui,P.F.Luckham,O.K.Matar,The spreading of surfac-

tant solutions on thin liquid?lms,Adv.Colloid Interface Sci.106(2003) 183–236.

[45]A.F.M.Leenaars,J.A.M.Huethorst,J.J.van Oekel,Marangoni dry-

ing:a new extremely clean drying process,Langmuir6(1990) 1701–1703.

[46]E.L.Ong,A.D.Roberts,Experiments on the lubrication of raw natural

rubber,J.Nat.Rubber Res.1(1986)41–50.

[47]A.Browne,K.C.Ludema,S.K.Clark,Contact between the tire and road-

way,in:S.K.Clark(Ed.),Mechanics of Pneumatic Tires,U.S.Department of Transportation,Washington,DC,1981,pp.315–317.

[48]B.N.J.Persson,U.Tartaglino,E.Tosatti,O.Albohr,Rubber friction on wet

rough substrates at low sliding velocity:the sealing effect,Kautsch Gummi Kunstst57(2004)532–537.

[49]J.Timmermans,Physico-Chemical Constants of Pure Organic Compounds,

Elsevier,Amsterdam,1950.

[50]E.Kokkoli,C.F.Zukoski,Effect of solvents on interactions between

hydrophobic self-assembled monolayers,J.Colloid Interface Sci.209 (1999)60–65.

[51]G.Papastavrou,S.Akari,H.M¨o hwald,Interactions between hydrophilic

and hydrophobic surfaces on microscopic scale and the in?uence of air bubbles as observed by scanning force microscopy in aqueous and alcoholic mediums,Europhys.Lett.52(2000)551–556.

[52]J.D.Carter,Re-evaluation of orientation effects in the friction of a hard

ellipsoid sliding on rubber,J.Appl.Phys.93(2003)1283–1286.

X.-D.Pan/Wear262(2007)707–717717

[53]N.Amino,Y.Uchiyama,T.Iwai,M.Maeda,Studies of friction mechanism

in silica and carbon black?lled SBR:(3)friction of carbon black and silica ?lled SBR blends,Int.Polym.Sci.Technol.30(2003)13–20.

[54]A.Schallamach,A theory of dynamic rubber friction,Wear6(1963)

375–382.

[55]Y.B.Chernyak,A.I.Leonov,On the theory of the adhesive friction of elas-

tomers,Wear108(1986)105–138.

[56]G.Luengo,J.N.Israelachvili,S.Granick,Generalized effects in con-

?ned?uids:new friction map for boundary lubrication,Wear200(1996) 328–335.[57]E.E.Meyer,Q.Lin,T.Hassenkam,E.Oroudjev,J.Israelachvili,Origin of

the long-range attraction between surfactant-coated surfaces,Proc.Natl.

Acad.Sci.U.S.A.102(2005)6839–6842.

[58]E.E.Meyer,K.J.Rosenberg,J.Israelachvili,Recent progress in under-

standing hydrophobic interactions,Proc.Natl.Acad.Sci.U.S.A.,in press (2006).

[59]X.-Y.Zhang,Y.-X.Zhu,S.Granick,Hydrophobicity at a Janus interface,

Science295(2002)663–666.

[60]S.Granick,Y.-X.Zhu,H.-J.Lee,Slippery questions about complex?uids

?owing past solids,Nat.Mater.2(2003)221–227.

热轧工艺流程电子教案

热轧工艺流程 热轧工艺流程----初学必看 1.主轧线工艺流程简述 板坯由炼钢连铸车间的连铸机出坯辊道直接送到热轧车间板坯库，直接热装的钢坯送至加热炉的装炉辊道装炉加热，不能直接热装的钢坯由吊车吊入保温坑，保温后由吊车吊运至上料台架，然后经加热炉装炉辊道装炉加热，并留有直接轧制的可能。 连铸板坯由连铸车间通过板坯上料辊道或板坯卸料辊道运入板坯库，当板坯到达入口点前，有关该板坯的技术数据已由连铸车间的计算机系统送到了热轧厂的计算机系统，并在监视器上显示板坯有关数据，以便工作人员进行无缺陷合格板坯的核对和接收。另外，通过过跨台车运来的人工检查清理后的板坯也需核对和验收，并输入计算机。进入板坯库的板坯，由板坯库计算机管理系统根据轧制计划确定其流向。 常规板坯装炉轧制：板坯进入板坯库后，按照板坯库控制系统的统一指令，由板坯夹钳吊车将板坯堆放到板坯库中指定的垛位。轧制时，根据轧制计划，由板坯夹钳吊车逐块将板坯从垛位上吊出，吊到板坯上料台架上上料，板坯经称量辊道称重、核对，然后送往加热炉装炉辊道，板坯经测长、定位后，由装钢机装入加热炉进行加热。 碳钢保温坑热装轧制：板坯进入板坯库后，按照板坯库控制系统的统一指令，由板坯夹钳吊车将板坯堆放到保温坑中指定的垛位。轧制时，根据轧制计划，由板坯夹钳吊车逐块将板坯从保温坑取出，吊到板坯上料台架上上料，板坯经称量辊道称重、核对，然后送往加热炉装炉辊道，板坯经测长、定位后，由装钢机装入加热炉进行加热。 直接热装轧制：当连铸和热轧的生产计划相匹配时，合格的高温连铸板坯通过加热炉上料辊道运到称量辊道，经称重、核对，进入加热炉的装炉辊道，板坯在指定的加热炉前测长、定位后，由装钢机装入加热炉进行加热。其中一部分通过卸料辊道运输的直接热装板坯需通过吊车吊运一次放到上料辊道后直接送至加热炉区。如果炼钢厂可以实现直接热装板坯由上料辊道运送，则可减少部分吊车吊运作业。 板坯经加热炉的上料辊道送到加热炉后由托入机装到加热炉内，加热到设定温度后，按轧制节奏要求由出钢机托出，放在加热炉出炉辊道上。 加热好的板坯出炉后通过输送辊道输送，经过高压水除鳞装置除鳞后，将板坯送入定宽压力机根据需要进行侧压定宽。定宽压力机一次最大减宽量为350 mm。然后由辊道运送进入第一架二辊可逆粗轧机轧制及第二架四辊可逆粗轧机进轧制，根据工艺要求将板坯轧制成厚度约为30-60mm的中间坯。在各粗轧机前的立辊轧机可对中间坯的宽度进行控制。

水工艺设备基础

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第一章水工艺设备常用材料 1.水工艺设备常用的金属材料主要有：碳钢、铸铁、合金钢、不锈钢及部分有色金属材料等。 2.钢的分类：按化学成分分为碳钢和合金钢，按硫磷含量分为普通钢、优质钢、高级优质钢，按用途分为结构钢、工具钢、特殊性能钢。 3.钢的编号：Q+数字表示屈服强度值；标注A、B、C、D，表示钢材质量等级，A级最低，D级最高；标注F为沸腾钢，未标注为镇静钢：如q235—A·F，表示屈服强度为235MPa的A级沸腾钢。 4.合金结构钢编号：利用“两位数字+元素符号+数字”来表示，两位数字代表钢种平均含碳量的万分之几，元素符号表示钢中所含的合金元素，数字代表该元素的平均含量的百分之几，若平均含量低于1.5%，则不标明含量，若平均含量大于1.5%、2.5%、3.5%……，则相应地以2、3、4……表示。如12CrNi3钢，其平均含碳量为0.12%，平均含铬量小于1.5%，平均含镍量为3%。 5.合金工具钢：当其平均含碳量大于或等于1.00%时，含碳量不予标出，小于1.00%时，以千分之几表示，其余表示方法与合金结构钢相似，如9SiCr，其平均含碳量为0.9%，硅和铬的平均含量均小于1.5%。 6.金属的基本性能是指它的物理性能、机械性能、化学性能和工艺性能。 7.钢中的有益元素包括锰和硅，有害元素包括硫（热脆、断裂韧性降低）和磷（冷脆、但提高在大气中耐蚀性）。 8.材料的机械性能主要指材料的弹性、塑性、强度和韧性（冲击韧性、断裂韧性、无塑性转变温度）。 9.材料的工艺性能主要指材料的可焊性、可锻性、切削加工性、成型工艺性和热处理性能。 10.有色金属：工业上钢铁称为黑色金属，除钢铁以外的金属称为有色金属。 11.铜合金及其编号：铜与锌组成的合金称为黄铜，HSn70—1表示含铜70%，含锡1%的锡黄铜；铜合金中的主加元素不是锌而是锡、铝、硅等其他元素，称为青铜，QSn4—3，表示平均含锡量4%，含锌量3%的锡青铜。 12.无机非金属材料包括天然岩石、铸石、陶瓷、搪瓷、玻璃、水泥等。 13.陶瓷以黏土为主要原料，其刚度、硬度是各类材料中最高的，在室温下几乎没有塑性，具有很好的耐火性能和不可燃烧性，最大的缺点是脆性和热稳定性低，大多数陶瓷是良好的绝热体和绝缘体。 14.陶瓷和搪瓷的区别：搪瓷是金属和瓷釉的复合材料，兼有金属设备的力学性能和瓷釉的耐腐蚀性能。 15.高分子化合物的合成：加聚反应（无副产物）、缩聚反应（析出低分子物质）。 16.高分子材料性能：重量轻、高弹性、滞弹性、塑性和受迫弹性、强度（比金属低）与断裂（脆性断裂、韧性 断裂）、韧性（好）、减摩、耐磨性（好）、绝缘性（好）、耐热性（差）、耐蚀性（只化学腐蚀）、老化。 17.高分子材料主要包括合成树脂、合成橡胶和合成纤维三大类。 18.塑料的组成：塑料是指以有机合成树脂为主要组成材料，与其他配料混合，通过加热、加压塑造成一定形状的产品。塑料的性能主要取决于树脂，但在合成树脂中加入添加剂可对塑料进行改性。组成塑料的物质主要包括：合成树脂、填料（或增强材料）、固化剂、增塑剂、稳定剂、润滑剂、着色剂、阻燃剂。 19.塑料按受热性能分为热塑性塑料（加热时软化，可塑造成型，冷却后变硬，此过程可反复进行），热固性塑料（初加热时软化，可塑造成型，但固化后再加热，将不再软化，也不溶于溶剂）。 20.复合材料：为多相或多组成体系，全部相可分为两类，一类为基本相，主要起胶粘剂作用；另一类为增强相，起提高强度或韧性的作用。 21.复合材料性能特点：比强度和比刚度高、抗疲劳性能好、减振能力强、高温性能好、断裂安全性高。 第二章材料设备的腐蚀、防护与保温 1.腐蚀：是材料与它所处环境介质之间发生作用而引起材料的变质和破坏。 2.金属氧化的条件：金属氧化物的分解压低于0.022MPa，该金属就有可能在空气中氧化。 3.金属氧化膜起保护作用的条件： ①生成的金属膜必须致密、完整，能把金属表面全部遮盖住； ②金属氧化物本身是稳定、难溶和不挥发的，且不易于介质作用而被破坏； ③氧化膜与基体结合良好，有相近的热胀系数，不会自行或受外界作用而剥离脱落； ④氧化膜有足够的强度、塑性，足以经受一定的应力、应变的作用。 4.钢铁的气体腐蚀：钢铁在高温气体环境中很容易受到腐蚀，常见类型有：高温氧化、脱碳、氢蚀和铸铁肿胀；防止措施：合金化、改善介质、应用保护性覆盖层。

最新作业-给排水设备工艺黄廷林-主编-课后答案

精品文档 第一章水工艺设备常用材料 1. 金属材料的基本性能包括哪几个方面的内容？你认为水工艺设备对金属材 料的哪些性能要求更高？怎样才能满足这些要求？答：使用性能：1 化学性能：抗氧化性和耐腐蚀性。2 物理性能：密度，熔点，热膨胀系数，导热性以及弹性模量等。3 机械性能：弹性，塑性，强度和韧性。工艺性能：可焊性，可锻性，切削加工性，成型工艺性，热处理性能。我觉得水工艺设备对金属材料的强度，刚度和抗腐蚀性的性能要求更高。按照实际的工程需要，通过不同材料间的比较，从中选出较优的材料。 2. 影响钢材性能的因素主要有哪些？答：碳是决定钢材的主要元素，随含碳量增加，钢的强度和硬度将不断提高，而塑性和韧性则会随之下降。硫是一种有害元素，产生“热脆”现象。磷也是一种有害元素，产生“冷脆”现象。锰是一种有益元素，作为脱氧剂和合金元素，减轻硫的有害作用，提高钢的强度和硬度。硅是一种有益元素，作为脱氧剂和合金元素，提高强度，硬度，弹性，降低塑性和韧性。氧，氮：未除尽的氧氮大部分以化合物形式存在，降低强度，冷弯性能和焊接性能。氧增加热脆，氮增加冷脆。钛，钒，铌：钢的强脱氧剂和合金元素，改善韧性，提高强度。 3. 不锈钢有哪些类型？在酸性介质、碱性介质及中性水溶液中是否可以选用同一种不锈钢？简述理由。答：按显微组织为马氏体不锈钢，铁素体不锈钢和奥氏体不锈钢。按化学成分为铬不锈钢和铬镍不锈钢。不可以，因为不同介质溶液中PH值不同，对不锈钢的化学反应都不一样，所以不能用同一种不锈钢，应该有 所针对的选择。 4、高分子材料主要有哪些类型？耐蚀有机高分子有哪些类型？各有什么特点？答：按照化学组分分：碳链有机聚合物、杂链有机聚合物、元素有机聚合物、无机聚合物。常用于水工程及水工艺设备中的高分子材料有：塑料、橡胶、纤维和胶粘剂等。耐蚀有机高分子类型有：热塑性树脂、工程塑料类、热固性树脂等。热塑性树脂中聚乙烯、聚丙烯的应用占主流。工程塑料类虽然有优异的耐腐性能，但因其价格的原因， 在中等的腐蚀环境中首选的仍是价廉易得、加工容易的材料。热固性树脂大多制成复合材料使用。 5.复合材料主要有哪些性能特点？ 答：比强度和比刚度高，抗疲劳性能好，减振能力强，高温性能好，断裂安全性高。 精品文档． 精品文档第二章、材料设备的腐蚀、防护与保温 答：氢蚀是指在高温高压环境下，1. 什么叫氢蚀？它对钢的性能有什么影响？氢蚀后使钢材力学性氢进入金属内与一种组分或元素产生化学反应使金属破坏。能下降，强度、塑性下降，呈脆断性破坏、氢蚀一旦发生，便无法消除，是不可逆的。随着腐蚀过程的进行，在多数情什么叫极化？极化对金属腐蚀有什么影响？ 2. 金属的腐蚀随极这个现象称为极化，况下，阴极或阳极过程会受到阻滞而变慢，

轧钢工艺过程介绍(介绍的比较详细)

一、钢铁的冶炼流程和主要设备 一般来说，钢铁的冶炼大致分为四个过程：炼铁、炼钢、热轧、冷轧。 其中我们着重介绍热轧、冷轧的流程和主要设备。 1.热轧 热轧是在钢的再结晶温度以上进行的轧制，轧制过程就是在旋转的轧辊间改变钢坯形状的压力加工过程。热轧时金属塑性高，变形抗力低，大大减少了金属变形的能量消耗。所以热轧能显著降低能耗，降低成本。此外热轧能改善金属及合金的加工工艺性能，即将铸造状态的粗大晶粒破碎，显著裂纹愈合，减少或消除铸造缺陷，将铸态组织转变为变形组织，提高合金的加工性能。 热轧通常采用大铸锭，大压下量轧制，不仅提高了生产效率，而且为提高轧制速度、实现轧制过程的连续化和自动化创造了条件。一般可在带钢热轧机上生产厚度为1.2～8mm 成卷热轧带钢。热轧工艺一般是将连铸的钢板板坯进过加热炉加热到一定温度，经过传送辊道到轧机处进行轧制成带钢、型钢或钢管。带钢还需要经过卷取机卷成钢卷

以便运输。 热轧厂主要设备：加热炉、传送辊道、轧机 （1）加热炉 现在一般采用步进加热炉来加热板坯，以提高自动化程度和生产率。 涉及到的传动产品：链条、轴承、联轴器、电机、减速箱、密封、液压胶管、工业胶管等等。 （2）传送辊道 热轧基本是靠辊道来运输钢坯或带钢。一般有链条传送和棍子传送两种。

涉及到的传动产品：链条、轴承、联轴器、电机、减速箱、密封等等。 （3）轧机 轧机是热轧的关键设备，直接决定了产品质量的好坏。为减少轧辊弹变而影响带钢厚度精度，国内使用的热轧机以四棍或六棍轧机为主。 轧机模型：

涉及到的传动产品：轴承、联轴器、电机、减速箱、密封、液压胶管、工业胶管等等。 （4）冷轧 冷轧是利用热轧钢卷为原料，经酸洗去除氧化皮后进行轧制。冷轧通常采用纵轧（轧辊轴线相平行，旋转方向相反，轧件作直线运动的轧制方法）的方式。冷轧生产的工序一般包括开卷、轧制、脱脂（酸洗）、退火(热处理)、卷取等，生产汽车板还需要镀锌等工艺。 酸洗工艺流程图： 镀锌工艺流程图：

水工艺设备基础考试复习要点完整版

水工艺设备基础考试复 习要点

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水实用工艺设备基础复习参考

实用文档 水工艺设备基础复习参考 一、填空题 1、在水处理工艺中，搅拌器的形式多种多样，应根据工艺要求来选用，常用的搅拌器有：浆式 搅拌器、推进式搅拌器、涡轮搅拌器等。 2、合金工具钢9SiCr钢表示：平均含碳量为0.9%，硅和铬的平均含量小于1.5% 。 3、陶瓷的最大缺点是脆性，它是阻碍陶瓷作为结构材料广泛应用的首要问题，是当前的 重要研究课题。 4、机械性能主要指材料的弹性、塑性、强度和韧性。 5、焊接的方法很多，大体可分为三大类：即熔化焊、压力焊和钎焊。 6、膜组件主要分为板式膜组件、管式膜组件、螺卷式膜组件和中空纤维膜组件。 7、Ni－Mo合金是耐盐酸腐蚀的优异材料。最有名的哈氏合金（0Cr16Ni57Mo16Fe6W4） 能耐室温下所有浓度的盐酸和氢氟酸。 8、机械传动的主要方式有齿轮传动、带传动和链传动。 9、离子交换膜的基本性能交换容量和含水率。 10、物质的导热系数值不仅因物质的种类、结构成分和密度而异，而且还和物质温度、 湿度和压力等因素有关。 11、HSn65-3表示的意义为: 含铜65%、含锡3％的锡黄铜。 12、金属发生应力腐蚀的三个必要条件是：敏感金属、特定介质和一定的静应力。 13、改变介质的腐蚀特性一般有两种途径：一种是去除介质中有害成分；另一种是加缓 蚀剂。

14、吸附装置分为固定床、移动床和流化床。 实用文档 15、通常可将极化的机理分为活化极化、浓差极化和电阻极化。 16、反渗透、超滤、微滤和纳滤设备都是依靠膜和压力来进行分离的。 17、按照化学成分钢主要可分为碳钢和低合金钢。 18、30CrMnSi的意义是：平均碳含量低于0.3%，铬锰硅三种合金元素均小于1.5% 19、金属材料的基本性能是指它的物理性质、化学性质、机械性能和工艺性能。 20、高分子化合物的合成中，最常见的聚合反应有加聚反应和缩聚反应。 21、腐蚀防护设计除正确选材外，具体还包括防蚀方法选择、防蚀结构设计、防蚀强度设 计以及满足防蚀要求的加工方法。 22、按照作用原理不同，电化学保护分为阴极保护和阳极保护。 23、根据缓蚀剂的不同作用特点，缓蚀机理共分为吸附理论、成膜理论、电极过程抑制理 论。 24、金属切削加工分为钳工和机械加工两个部分。 25、热量传递有三种基本方式：热传导、热对流和热辐射。 26、导热过程的单值条件一般有几何条件、物理条件、时间条件和边界条件。 27、凝结换热是蒸汽加热设备中最基本的换热过程。 28、按形状区分，封头分为凸形封头、锥形封头和平板形封头

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水工艺试题

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4 ．非金属材料腐蚀主要由引起的。 A 应力作用 B 化学作用 C 微生物作用 D 物理作用 5 ．从防腐角度考虑，下列哪种设计较为合理： 6 ．下列气浮分离设备应用最广泛的是。 A 微孔布气气浮设备 B 压力溶气气浮设备 C 电解气浮设备 D 射流气浮设备 7 ．渗透压与溶液的，和有关，而与无关。 A 膜、浓度、温度、溶液性质 B 浓度、温度、溶液性质、膜 C 、温度、膜、浓度、溶液性质 D 溶液性质、浓度、膜、温度 8 ．计量泵流量为Q = F S n 其中S 表示。 A 柱塞断面积 B 冲程 C 时间 D 吸水管断面积 9 ．离子交换膜按结构分为。 A 均相 B 半均相 C 复合膜 D 异相膜 10 ．发生应力腐蚀的三个必要条件。 A 一定空气湿度 B 敏感的合金 C 特定的介质 D 一定的静应力 三名词解释（共30 分，每题5 分） 1 ．老化 2．吸氧腐蚀 3．阴极极化 4．细菌腐蚀

水工艺设备重点总结

水工艺设备 金属材料是目前水工艺设备材料的主体。 金属材料的特点：良好的塑性和变形性能、导电性和导热性、对光具有良好的反射性能。金属材料的分类： 1.钢：碳钢和低合金刚（化学成分）普通钢和优质钢和高级优质钢（质量）结构钢和工具钢和特殊性能钢（用途） 2.铸铁3：有色金属及其合金 金属材料的基本性能： 1.物理性能：密度大熔点高，热膨胀系数（指材料在温度变化一度时单位长度的伸缩变化值）导热性，导电性和弹性模量（弹性极限内应力和应变的比值）。 机械性能：弹性，塑性，强度（金属材料在外力的作用下抵抗塑性变形和断裂的能力）和韧性（材料对缺口或裂纹敏感程度的反应，用来衡量材料的抗裂纹扩展能力） 工艺过程：可焊性，可锻性，切削加工性，成型工艺性，热处理性。 工艺性能：材料在加工方面的物理化学和机械性能的综合表现构成了材料的工艺性能。 化学性能：耐腐蚀性 不锈钢有哪些类型？在酸性介质、碱性介质及中性水溶液中是否可以选用同一种不锈钢？简述理由。 答：按显微组织为马氏体不锈钢，铁素体不锈钢和奥氏体不锈钢。按化学成分为铬不锈钢和铬镍不锈钢。不可以，因为不同介质溶液中PH值不同，对不锈钢的化学反应都不一样，所以不能用同一种不锈钢，应该有所针对的选择。 化学成分：C钢的主要元素之一，含量增加强度和硬度增加，塑性和韧性减小 S一种有害元素，热加工时容易开裂，“热脆” P一种有害元素，低温时容易变脆，“冷脆” Mn一种有益元素，可以提高钢的强度和硬度 Si一种有益元素，强硬弹增加，塑韧减小。耐蚀，热性增加。 金属材料的耐蚀性能：1.碳钢和铸铁在但水大气土壤海水等中性介质中都不耐腐蚀。 2.在各类干燥气体和有机溶剂等介质中耐蚀性良好。 3.在低浓度碱溶液剂及浓硫酸浓氢氟酸等介质中碳钢和普通铸铁表面能生成稳定的膜。 高分子材料主要有哪些类型？高分子材料主要有哪些性能？ 答：按照化学组分分：碳链有机聚合物，杂链有机聚合物，元素有机聚合物，无机聚合物。主要性能有重量轻，高弹性，滞弹性，塑性与受迫弹性好。强度和断裂，韧性，减磨与耐磨性，绝缘性，耐热性，耐蚀性，老化。 10.塑料的组成如何？常用塑料的分类和特点如何？ 答：组成：合成树脂，填料，固化剂，增塑剂，稳定剂，润滑剂，着色剂，阻燃剂，其他添加剂。按受热性能分为热塑性塑料：加热时软化，可塑造成型，冷却后则变硬，此过程可反复进行；热固性塑料：初加热时软化，可塑造成型，但固化之后再加热，将不再软化，也不溶于溶剂。按使用范围分通用塑料：应用范围广，生产量大的品种；工程塑料：综合工程性能良好；耐热塑料：能在较高温度下工作。 11. 复合材料主要有哪些性能特点？ 答：比强度和比刚度高，抗疲劳性能好，减振能力强，高温性能好，断裂安全性高。