USAGE OF PRESSURE OSCILLATIONS OF FLUCTUATING GAS FLOW FOR HANDLING OF 40X HARDENED STEEL SAMPLES

• Published in: Nauchno-tekhnicheskiĭ vestnik informat͡s︡ionnykh tekhnologiĭ, mekhaniki i optiki mekhaniki i optiki, 2016-07, Vol.16 (4), p.635
• Main Authors: Il'ina, E E, Prodan, N V, Vologjanina, S A
• Format: Article
• Language: Russian
• Subjects: Aeroacoustics; Annealing; Component reliability; Gas flow; Hardness; Heat treating; Heat treatment; Impact strength; Low temperature; Low temperature resistance; Pressure oscillations; Residual stress; Shock waves; Solid phases; Statistical analysis; Statistical methods; Steel; Steel construction; Substructures; Surface hardness; Toughness; Wear resistance
• ISSN: 2226-1494; 2500-0373
• DOI: 10.17586/2226-1494-2016-16-4-635-641

Subject of Research. The paper deals with experience in the use of advanced technology of aeroacoustic treatment of materials for impact toughness improvement of the 40X type constructional steel samples. The method is based on the influence of pulsating air stream with oscillating shock-wave structures on the sample. As a result, the so-called Maxwell's waves are generated in the sample, that can lead to a beneficial transformation in the micro- and substructure and also in the phase structure of hardened steels. Obtained changes may be enough to improve impact toughness and decrease the residual stresses that arise in the course of previous treatments. Distortion of components decreases in this case, and failure probability becomes lower at the further treatment and operation. The advantage of technology is elimination of the additional heat treatment, for example, of the relaxation annealing that serves to reduce the residual stresses. This can be useful, particularly, for the preservation of high hardness and wear resistance, obtained by hardening and low-temperature tempering (about 200 ° C), as the relaxation annealing has typically a higher temperature and will result in their reduction. The toughness increase of the samples is assumed as an indicator of the positive impact of the considered treatment. Main Results. We have defined characteristics and modes of experimental acoustic transducer implementing the aeroacoustic processing. Experiments have been carried out on the impact assessment of aeroacoustic effects on the toughness of widely used 40X type steel. The obtained results enable to suggest that the application of aeroacoustic treatment for samples hardened by heat treatment leads to the toughness increasing of the investigated material. In this case an increased value of hardness obtained after heat treatment is maintained. Practical Relevance. The results supplement previously obtained experimental data for aeroacoustic processing of metallic materials. They can be used (after increasing data statistical reliability) in development of component treatment technology, where there is important to have high hardness and wear resistance with adequate toughness.