Surface hardening of steel 18Kh2N4VA with different stress concentrators

The theoretical justification for the hardening process of the surface layer of machine parts for combined methods of surface hardening with subsequent application of strengthening coatings, as well as reducing or increasing the fatigue limit due to the fretting process is presented.

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On effect of surface hardening on impact and abrasive wear resistance of Hadfi eld steel

10.36652/1813-1336-2020-16-6-252-255 ◽

2020 ◽

pp. 252-255

Author(s):

V.I. Bolobov ◽

V.S. Bochkov ◽

E.V. Akhmerov ◽

V.A. Plashchinsky ◽

E.A. Krivokrisenko E.A.

Keyword(s):

Plastic Deformation ◽

Wear Resistance ◽

Abrasive Wear ◽

Work Hardening ◽

Surface Hardening ◽

Cold Work ◽

Abrasive Wear Resistance ◽

Hadfield Steel ◽

Mining Equipment ◽

Effect Of Surface

On the example of Hadfield steel, as the most common material of fast-wearing parts of mining equipment, the effect of surface hardening by plastic deformation on their impact and abrasive wear resistance is considered. Wear test is conducted on magnetic ironstone as typical representative of abrasive and hard rock. As result of wear of initial samples with hardness of ∼200 HB and samples pre-hardened with different intensities to the hardness of 300, 337 and 368 HB, it is found that during the initial testing period, the initial samples pass the “self-cold-work hardening” stage with increase in hardness to ∼250 HB, which remains virtually unchanged during further tests; the hardness of the pre-hardened samples does not change significantly throughout the tests. It is established that the rate of impact-abrasive wear of pre-hardened samples is significantly (up to 1.4 times) lower than the original ones that are not subjected to plastic deformation, and decreases with increasing degree of cold-work hardening. Preliminary surface hardening by plastic deformation can serve as effective way to increase the service life of fast-wearing working parts of mining equipment.

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Use of ultrasonic surface hardening in modifi cation of surface layer

10.36652/1813-1336-2020-16-5-200-204 ◽

2020 ◽

pp. 200-204

Author(s):

Yu.S. Semenova ◽

A.G. Samul’ ◽

S.V. Mazhuga

Keyword(s):

Surface Layer ◽

Chemical Treatment ◽

Surface Hardening ◽

Manufacturing Cost ◽

Ultrasonic Vibrations ◽

Surface Microrelief ◽

Scientific Schools ◽

Structure Changes ◽

Wide Range ◽

Finishing Machining

Overview of the research results got by various scientific schools in the field of application of ultrasonic surface hardening is provided. Wide range of opportunities of ultrasonic surface hardening is shown for the application in the preliminary machining of surfaces before thermal and chemical treatment, coating, and also as finishing machining. The effect of the energy of ultrasonic vibrations on structure changes in the material of the surface layer and on surface microrelief on parts performance is considered. The prospects of using of the ultrasonic surface hardening method in combination with other methods of the material modification are presented. In addition the possibilities of reducing the manufacturing cost of product by introducing ultrasonic surface hardening into the technological process are shown.

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