Effect of electrisation and small direct currents on the wear of metals in sliding friction

Effect of electrisation and small direct currents on the wear of metals in sliding friction

SYSTEMATIC ABSTRACTS OF CURRENT LITERATURE Design, Operation and Lubrication Tractor-motor Gears and Gear Cases. of H. H. Koci and P. R. Bien, Lu...

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SYSTEMATIC

ABSTRACTS

OF CURRENT LITERATURE

Design, Operation and Lubrication Tractor-motor Gears and Gear Cases.

of

H. H. Koci and P. R. Bien, Lubrication Eng., 24 (12) (1968) 565-571; 7 figs., I table, 2 refs. The paper describes the problems associated with the design and operation of tractionmotor gearing and suggests solutions to some of the problems. The subject is divided into three areas, gear and pinion set, gear case and lubrication of the gears. Laboratory cants.

Evaluation

of Worm-gear

Lubri-

D. D. Domonoski, Lubrication Eng., .zg (12) (1968) 572-585; g figs., r3 tables, 9 refs. The paper compares the laboratory bench test performance of seven commercially available petroleum lubricants currently used in wormgear service. Accelerated wear and oxidation tests have been modified more closely to simulate worm-gear conditions. The results suggest that certain types of e.p. gear lubricants may out-perform compounded oils containing acidless tallow in worm-gear service. Survey of the Theory of Mechanical Face Seals-Part III. Dynamic and Interfacial Fluid Effects.

L. H. Bernd, Lubrication Eng., 24 (12) (1968) 597-604; r fig., 3 tables, 62 refs. Industrial

Filter Media.

A. London, Engineering, 207 (5368) (1969) 443-444; 6 figs. This is an outline of the subject covering basic facts, rating performance factors and classification of filters. Different filter media including paper, felts, cloths, sintered metal. absorbent material are described as well as the different types of filters available and their principles of operation.

5. AMATERIALS

AND WEAR

5.1. Materials and zerearresistance Corrosion and Abrasive-wear Properties of Precipitation-hardening Stainless Casting Steel. (in Czech)

A. Kabrhel, Mater. Sb., Statni Vyzkum. Ustav Mater. Technol., (Materials Miscellany-Steels for high temperatures and corrosive media) (1966) 171-190; 17 figs., 3 tables, 16 refs. The paper deals with tests of corrosion and abrasion resistance of seven different types of hardenable stainless steels for castings. On the basis of test results two types were selected for performance tests of pump components and mixing equipment exposed to combined corrosion and abrasion in the chemical industry.

375

Effect of Carbide Reactions on the Strengthening of Cobalt-base, Hard-facing Alloys. (in Czech)

K. Lobl, Mater. Sb., Statni Vyzkum. Ustav Mater. Technol., (MaterialsMiscellany-Steels for high temperatures and corrosive media) (1966) 191-210: 20 figs., 2 tables, 5 refs. A description is given of the variations of hardness of both laboratory and production scale melts of cobalt-based hard-facing alloys in the course of prolonged isothermal annealing during which the carbide phases precipitate and coagulate. The mode of precipitation has been investigated by electron microscopy on fracture surfaces of specimens subjected to various heat treatments. The results are discussed. Mechanical ised Layers.

Properties

of Diffused

Chrom-

F. P. Ponomarenko, A. I. Plyshevskii, V. P. Khokhlov and L. I. Filina, Soviet Mater. Sci., 3 (2) (1967) 128-130; 5 figs., I table. (Translation by the Faraday Press, New York, of Fiz.-Khim. Mekhan. Mater., 3 (2) (1967) 178-181.) The mechanical properties of thermo-diffused layers obtained by vacuum chromising of steel were studied. It was established that to produce strong and ductile chromised layers by this method it is necessary to decarburise the substrate material before or after the treatment. Wear of Metals in Sucrose Solutions. N. A. Sologub, Soviet Mater. Sci., 3 (2) (1967)

139141; 5 figs., I table, 8 refs. (Translation by the Faraday Press, New York: of Fiz.-Khim. Mekhan. Mater., 3 (2) (1967) 193-196.) A study of the wear of steel rubbing against cast iron, bronzes and babbit in aqueous solutions containing up to 80% sucrose. The maximum resistance to wear was shown by the steel/bronze 5-5-5 combination and the minimum by the steel/babbit combination. At sucrose concentrations above 60% abrasive wear associated with the presence of sucrose needles becomes predominant; the steel/cast iron combination shows the least wear and the steel/babbit combination the largest. Wear and coefficient of friction of the steel/bronze 9-4 combination continuously decrease with increase of sucrose concentration. Effect of Electrisation and Small Direct Currents on the Wear of Metals in Sliding Friction. L. G. Korshunov and R. I. Mints, Soviet Mater. Sci., 3 (4) (1967) 284-287; 4 figs., 2 tables, 4 refs. (Translation by the Faraday Press, New York, of Fiz.-Khim. Mekhan. Mater., 3 (4) (1967) 392-396.) The magnitude and direction of thermally wear> =3 (1969) 371-379

induced electric currents depend on both friction conditions and the rubbing materials; the influence of electrisation on wear is complex. Currents of the order of IO-~~IO-~ X may have a noticeable effect on the wear of metals due to electro-transfer phenomena in the metal surface layers during friction. Corrosion Resistance of Steel for Rotary Diffusers. V. I<. Suprunchuk et al., Sowet Matrv. Sci., 3 (4) (1967) 304-306; 4 figs., 9 rcfs. (Translation by the Faraday Press,Scw York, of I;iz.-Khinz. !If&hU%. Mafev., 3 (4) (1967) 417~420.) The effect of static and cyclic stresses on the corrosion-inducetl wear of steel in continuous rotary diffusers in sugar refining was studied and the cortosion fatigue strength investigated 21 change from a coarse to a fine crystalline structure is attributed to plastic tleformation in the stressed diffuser parts. Effect of Non-metallic Inclusions on Properties of Cast Steel. \-u. .1. Shul’ti et al., Soviet Matr,,. Ski., 3 (4) (1967) jog-3rr; 2 figs., 1 table, 5 refs. (Translation by the Faraday Press, New York, of ITi:.-Klzz?lz. Mpkhan. XI&r., 3 (4) (‘90;) 42 +--427.) .\ new linear method of determining the content and shape of nonmetallic inclusions xvas usc%tl to study their vffect on physicochemical and electro-chemical properties of cast steel. By improving techniques of prccasting dcoxidation and adjusting the composition of deoxidising additions it is possible to improve considerably the physico-chemical and clcctro-chemical properties of cast steel. Effect of Crystal Lattice and Degree of Dispersion of Alloy Constituents on the Resistance to Damage due to Abrasive Wear. \-. S. l’opov and N. N. Brykov, Soui~~lMater. ski., 3 (4) (1967) 315-317; I table, 1 ref. (Translation by the Faraday Press, Xew York, of I;,.-Klziaz. Mekhan. Mntrr , ,j (4) (~907) 4.3~~435.) .\brasivc wear tests carried out under industrial conditions on facing plates of dies for pressing refractory parts showed that the htructure of alloys has a substantial effect on their wear resistance. The first stage of tlisintcgration by abrasive wear is the formation of submicroscopic cracks due to interaction of dislocations on two intersecting slip planes. The interaction of dislocations occurs more readily in b.c.c. than in f.c.c. metals It was established that a b.c c. lattice has a lower resistance to plastic deformation so that the degree of plastic deformation preceding fracture is smaller in b.c.c. than in f.c c. metals. To increase wear resistance alloy5 with a f.c.c. metallic matrix should

bc used with treatments which increase the dispersion of alloy structural constituents. Thermodynamic and Structural Factors Determining the Wear Resistance of Aluminium Cast Iron. .\. .I. Zhukov and A. I’. Ogarcv, SouretMater Ski., 3 (4) (1967) 331-333; 2 figs , 4 tables, (>rcfs. (Translation by the Faraday l’ress, New York, of Fit.-Khim. AZekhan. Mntw., 3 (4) (~0077) 454-457.) Jlodification of aluminium-containing cast iron with ccrium leads not only to sphcroitlization of graphite but also to the formation of ~1’ phase dendrites with a corresponding reduction in the carbide content in the fcrritic matrix surrounding they’ phase dendrites ant1 pearlite. This has a beneficial effect on wear rcsi stance. The Present State and Future Paths of Scientific Research in Physico-chemical Mechanics of Materials. (G. V. Karpenko, Soviet 21f~t~~~. SC! , ,j (5) (1967) 367-381; 169 refs. (Translation by the Faraday I’ress, New York. of FEZ.-Khil”r2. Alrkhan. Alate+, , ,y (5) (1907) ,503 -5rr.) ,\ short review of research carried out 111 recent years in the field of I’l’ysico-chetnic;tl mechanics of materials. Eflect of Working Media in Friction and Wear of Iron-base Composite Materials. 1. $1.Fcdorchenko and L.\-. Zabolotayi, .Sovi?l ,Vatru. Sci., 3 (5) (1967) 389-393; 8 figs., 1 table, 0 refs. [Translation bv the Faraday Press, New York. bf I:i~.-I~Aim.~.1/Iekha~~. [email protected], 3 (5) (19~17) 5x3-539.) The effect of liquid lubricants on the antifriction properties of self-lubricating ironbased composite materials was studied. (‘rudr pctrolcum oil products have a higher loatlcarrying capacity and working temperature than highly refined products. :\n investigation of metal/polymer bearing material:, established that the effect of sliding spcctl and load on the coefficient of friction in gases and in vacuum is the same as under dry friction conditions. The wear resistance of materials in argon is ten times lower than in air. It is concluded that the choice of bearing materials suitable for vacuum applications is limited to those whose surfaces are not prone to seizure and are exemplified by metal/ poll-mer composites. Dry lubricants based on sulphides and selenides of certain metals ma! be used.

Metallurgical After-effect in Steel. (;. V. liarpcnko and .2. B. Iiuslitski, Soviri JTc/rtrar,. Sri., 3 (5) (“967) 4.54 -457; 4 figs., 0 r(,fi