AP13068365 "Evelopment of a resourse-saving method of surface hardening of the working bodies of soil-troad machines"
Supervisor: Kalitova Aisulu Amanzholova, PhD, - Project Manager ORCID ID - 0000-0002-4761-286x
Relevance:
In recent years, the speed of tillage has increased from 7 to 12 km/h, and sometimes up to 15-18 km/h. In this regard, the loads on the working bodies operating under conditions of intense, abrasive and shock-abrasive wear have also increased significantly. Therefore, modern agriculture requires reliable working bodies of machines with a number of high characteristics, such as: high strength and ductility, wear and corrosion resistance, and many others. This problem is solved mainly through the production of bulk alloy steels. However, due to the ever-increasing cost of alloying materials, it is advisable to use low-alloy steels with a hardened surface layer.
Target:
Development of a resource-saving method of electrolytic-plasma hardening of chisel plow bits of tillage machines made of steel grades 65G and 45, which makes it possible to increase their wear resistance under the influence of abrasive particles and high shock loads.
Expectation:
1. An industrial plant for electrolytic-plasma hardening of the working bodies of tillage machines will be manufactured.
2. The optimal mode of electrolytic-plasma hardening of steels will be established.
3. The main regularities of the formation of the dislocation substructure of steels during electrolytic-plasma hardening will be established.
4. The wear mechanisms of steels treated by electrolytic-plasma hardening will be established.
5. The interrelation of tribological and physical-mechanical properties with the structural-phase state of steels treated by electrolytic-plasma hardening will be established.
6. Bench and field tests of hardened chisel plow points will be carried out.
7. On the basis of the conducted experimental studies and tests, a resource-saving method of electrolytic-plasma hardening of the working bodies of tillage machines, in particular, chisel plow chisels, will be developed.
8. A recommendation will be issued on the use of electrolytic-plasma technology for hardening chisel plow bits.
Result:
Electrolytic-plasma hardening of steel samples was carried out on a laboratory setup at the Research Center for Surface Engineering and Tribology and the Research Center for Surface Modification of Materials. A metallographic microscope HL-102AW was used to study the general nature of the structure. The morphology and elemental composition of the sample treated in electrolytic plasma were studied using a JSM-6390 LVJEOL scanning electron microscope. For metallographic microanalysis, sections of steel samples were polished using chromium dioxide paste and etched with a 4% alcohol solution of nitric acid. The microhardness of steel samples was measured using an HV-1 DT device, with indenter loads of P = 1 N and a holding time of 10 sec under this load.
Experiments to study energy characteristics were carried out with electrolytes containing sodium carbonate with different. In all experiments, the voltage on the electrodes and the average current between them were recorded using pointer devices. To determine the optimal values of voltage and electrolyte composition, the following hardening modes were selected: 300 V, 4 sec, 15% (Na2CO3), 300 V, 4 sec, 20% (Na2CO3), 300 V, 4 sec, 25% (Na2CO3), 300 V, 3 sec, 20% (Na2CO3), 320 V, 3 sec, 20% (Na2CO3). The microhardness of grade 45 steel depending on the electrolyte composition were equal: at an electrolyte concentration of 15%, the average microhardness value was 356 HV, at 20% - 420 HV and at 25% - 434 HV. When changing the hardening time, it was found that higher average microhardness values were achieved at a voltage of 320 V. Metallographic examination of samples using optical and scanning electron microscopes revealed that electrolytic plasma hardening of grade 45 steel resulted in the formation of a surface layer containing martensite areas. The corrosion properties of grades 65G and 45 steels were studied using the electrochemical method before and after electrolytic plasma hardening using different concentrations of sodium carbonate (15%, 20% and 25%) with a change in the volt-ampere characteristics. The corrosion characteristics of grades 65G and 45 steels were studied before and after electrolytic plasma hardening using electrolytes with different sodium carbonate contents (15, 20 and 25%) and with a change in the volt-ampere characteristics of the process parameters. The electrochemical corrosion test was carried out using a CS300M potentiostat/galvanostat. An aqueous solution of 0.5 M NaCL was used as a medium for testing corrosion resistance. The following results were obtained: samples hardened in an electrolyte with a sodium carbonate concentration of over 20% showed a significant improvement in corrosion resistance with a decrease in the corrosion rate to 2.6*10-4 mm/year, which is 8 times lower than the original samples (2.1*10-3 mm/year). However, samples with a 15% sodium carbonate concentration showed only a slight improvement in corrosion resistance with a corrosion rate of 1.6*10-3 mm/year.These data are confirmed by the analysis of the Tafel curves, where the corrosion potential for samples 2-6 is also shifted to a more positive side compared to the original sample. A rig for accelerated testing of working bodies of soil- ultivating machines has been developed, which consists of a chamber with soil, which is an open-top cylinder with a diameter of 2 m made of steel sheet, and a compaction mechanism that includes heavy drums that ensure uniform compaction of the soil by crushing. The working body, such as a plough or cultivator, is driven by a drive and interacts with compacted soil, simulating operating conditions. Regulation of the degree of compaction is achieved by changing the position of the drums, which allows adapting the installation to different types of soil and working conditions. The efficiency and wear resistance of the working body are assessed by measuring the angle of rotation of the chamber, which reflects the resistance to movement in compacted soil. This installation will be used to conduct rig tests of hardened chisel plough chisels.
2024- Bauyrzhan Rakhadilov, Moldir Bayandinova, Rinat Kussainov, Almasbek Maulit. Electrolyte-plasma surface hardening of hollow steel applicator needles for point injection of liquid mineral fertilizers[J]. AIMS Materials Science, 2024, 11(2): 295-308. doi: https://doi.org/10.3934/matersci.2024016
- Bauyrzhan Rakhadilov, Rinat Kussainov, Aisulu Kalitova, Zarina Satbayeva, Aibek Shynarbek. The impact of technological parameters of electrolytic-plasma treatment on the changes in the mechano-tribological properties of steel 45[J]. AIMS Materials Science, 2024, 11(4): 666-683. doi: https://doi.org/10.3934/matersci.2024034
Study Team Members
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Fullname: Журерова Лайла Гылыммеденова, PhD
Scopus Id: 55899323400
Researcher Id: -
ORCID: 0000-0002-1924-1459
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Fullname: Касымов Аскар Багдатович, PhD
Scopus Id: 56298368800
Researcher Id: --
ORCID: 0000-0002-1983-6508
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Fullname: Кожанова Рауан Сабырбековна
Scopus Id: 57216911622
Researcher Id: --
ORCID: 0000-0002-3271-226_
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Fullname: Сатбаева Зарина Аскарбековна
Scopus Id: 57213689811
Researcher Id: --
ORCID: 0000-0001-7161-2686
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Fullname: Табиева Еркежан Еркинбеккызы
Scopus Id: 57222482979
Researcher Id: --
ORCID: 0000-0002-9726-7187
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