The prevention of abrasive wear is of great impor tance, since such wear can cause premature failure of components in mining, metallurgical, construction, and drilling equipment. We are particularly interested in the cylindrical bushes of borehole pumps, which are subject to cyclic loads at high variable pressure, as well as the abrasive action of borehole fluid with suspended solid particles. The complex loading results in rapid bush failure, on account of hydroabrasive wear and the appearance of impermissible gaps in the bush-piston assembly.In the present work, in connection with the devel opment of a production process for cylindrical 150XHM steel bushes of borehole pumps, we study the influence of the quenching temperature (in the range 850-1175°C) on the wear resistance, in combination with the structural strength of the bushes. The bushes are held at the specified temperature for 30 min, with subsequent cooling in oil.We study the microstructure and abrasive wear resistance on 10 × 10 × 25 mm samples taken from cast 150XHM steel pipe blanks after normalization and tempering. 1The wear resistance of the 150XHM steel sam ples is estimated on special equipment based on a planing machine. Samples with a 10 × 10 mm work ing area perform reciprocating motion over corun dum based 14A32MN481 abrasive paper (State Standard GOST 6456-82). The length of a single working pass is 0.135 m; the frictional path in a single 1 V.V. Yurovskikh (OAO Uralmashzavod) took part in these proce dures.test at 0.158 m/s is 120 m. The normal load on the sample is 10 kg (unit load 1 MPa). The transverse dis placement of the abrasive paper in a double pass is 1.2 mm. The abrasive wear resistance is determined from two parallel tests with the 150XHM steel samples and a standard sample (9X5МФС roller steel). The comparison is based on the relative wear resistance where ΔM st is the mass loss of the standard 9X5МФС roller steel sample after quenching from 900°C and low tempering (ΔM st = 0.4100 g); ΔM sa is the mass loss of the tested sample. To obtain more complete information regarding the life of 150XHM steel in abrasive wear, each sample is tested in two conditions:⎯with rigorous friction on fresh 14A32MN481 abrasive paper (mean particle size 140 μm); ⎯with moderate friction on repeatedly used 14A32MN481 abrasive paper (mean particle size 40 μm).The samples are tested with constant unit load 1 MPa on two 30 m segments of frictional path.The initial sample structure consists of tempering sorbite, nonuniformly distributed sections of carbide eutectic (ledeburite; around 5%, on average), and sec ondary cementite along the grain boundaries (Fig. 1a), with a mean hardness of 300 HV.After quenching from 850°C, the structure con tains not only martensite but excess cementite (Fig. 1b). After quenching from 1000°C, the structure consists of fine martensite needles with intragrain car Abstract-The influence of the quenching temperature on the quantity of residual austenite, its stability, and its ease of deformational martensitic transformatio...

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The paper studies the effect of quenching in a wide range of temperatures on the quantity of metastable residual austenite, its stability, hardening and wear resistance in the process of abrasive wear of high-carbon tool steels of the pearlitic and ledeburitic classes -150KhNML and Kh12MFL. Despite decreasing initial hardness with increasing quenching temperature, the abrasive wear resistance of the steels increases, this being due to a change in the quantity, composition and deformation stability of residual austenite. The increase in the relative wear resistance of both steels with increasing quenching temperature correlates with hardenability determined by measuring the microhardness of the gauge surface after wear. The cold treatment of the Kh12MFL steel after hightemperature quenching additionally enhances its abrasive wear resistance by 25 % due to the formation of 15 % of high-carbon-chromium cryogenic martensite and increases the initial hardness to 60 НRC with the preservation of 20 % of residual metastable austenite and carbides. Shabashov V.A., Korshunov L.G., Mukoseev A.G., Sagaradze V.V., Makarov A.V., Pilyugin V.P., Novikov S.I., Vildanova N.F. Deformation-induced phase transitions in a highcarbon steel. Materials Science and Engineering: A, 2003, vol. 246, pp.196-207. DOI: 10.1016/S0921-5093(02)00549-X. 2.Filippov M.A., Gervasiev M.A., Khudorozhkova Yu.V., Legchilo V.V. Effect of quenching temperature on the phase composition, structure and wear resistance of the 150KhNM steel. Izvestiya vysshykh uchebnykh zavedeniy.

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