| 摘要 |
machine engineering, namely repairing of machines, particularly worn inner cylindrical surfaces. SUBSTANCE: method comprises steps of placing sleeve into cooled die, heating sleeve by volume and cooling it in mode according to invention. Sleeve is heated by volume until (500-600)C, then surface of inner wall of sleeve is preliminarily heated until temperature AC1-(10-30)C at keeping temperature gradient between sleeve wall and inner cylindrical surface of cooled die. Then surface of inner wall of sleeve is heated until quenching temperature equal to AC1+(30-50)C and it is cooled by spraying liquid for martensite, troostite. Preliminary surface heating of inner wall of sleeve until temperature AC1 -(10-30)C is realized with use of inductor by one pass along sleeve axis at rate (2-2.5) mm/s. Heating until quenching temperature equal to AC1+(30-50)C and cooling by liquid spraying of inner surface of wall of sleeve are realized with use of inductor and sprayer by one pass along sleeve axis at constant rate (6- 8) mm/s. Such method allows to restore quenched gray-iron sleeves of cylinders of diesel engines of automobiles and tractors. Set of offered operations provides new quality properties of restored sleeves due to reduced stress-deformation state of sleeve at upsetting it by inner diameter. EFFECT: enhanced quality, increased useful life period of restored sleeves. 3 cl, 1 tbl
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