The main areas of activity of the department
Research of physico-chemical and heat-mass exchange processes in alloys during melting, processing and crystallization of ductile and special cast irons and development of scientific foundations for technologies of new cast materials with high operational characteristics obtaining. This direction includes:
- study of modifying reagents interphase interaction and kinetic regimes of their dissolution in iron-carbon melts;
- carrying out of fundamental research which results will create environmentally friendly processes of iron-carbon melts processing with new and low-melting modifiers in the pre-crystallization state of alloys;
- research of various modifiers influence on the iron-carbon alloys structure and properties and development of technologies for obtaining castings with increased operational characteristics from special and ductile cast irons;
- development of new special ductile cast irons (impact-resistant, wear-resistant, heat-resistant, corrosion-resistant and others) and technologies for their production;
- research of processes of post-eutectoid steels structure formation and spherical graphite formation in them.
Current projects:
- project III-44-23-723 "Creation of technological processes for obtaining high-strength pearlite cast irons with increased mechanical and functional properties for military equipment and vehicles";
- project III-40-22.719 "Development of the latest technologies for the production of multifunctional protective modules".
The most important achievements in scientific and practical activities
1. Have been developed parameters of highly efficient technologies of complex melt modifying and refining which are based on the joint introduction of FeSiMgCa master alloy and calcium fluorite that contributes to the formation of low-melting oxide-fluoride slag with high refining capacity. Due to this, the strength, plasticity and impact strength of ferritic ductile cast iron increases by 20-30 %, the casting yield increases from 45-50 % to 60-65 %, 350-400 kWh of electricity is saved at production of 1 ton castings, the service life of cast parts increases by 1.3-1.5 times.
2. Rational technological parameters of in-mold modifying process for ductile cast iron thin-walled castings obtaining with a minimum wall thickness of 2-3 mm without chill have been determined. Was developed a low-inertia gating-modifying system with a two-chamber flow reactor in which due to the creation of additional centrifugal motion the interphase interaction is accelerated and the melt at the output is effectively filtered from the residual products of the modifying process. The obtained scientific results provide reduction of modifiers consumption in 2,0-2,5 times, energy-intensive heat treatment (graphitizing annealing) elimination and increase in 1.5-5.0 times the metal use due to the reduction of wall thickness and mass of machine-building parts blanks.
3. New compositions of fast-dissolving FeSiMg master alloys with increased silicon content as well as calcium, barium, vanadium, manganese and copper have been developed which use ensures the production of high-quality ductile cast iron in as-cast state with strength and relative elongation that significantly exceed the corresponding indicators of DSTU 3925-99.
4. It was established that as a result of melt alloying with copper and normalization heat treatment applying to thin-walled castings from ductile cast iron modified in the pre-crystallization period its mechanical properties increase to the level of bainitic ductile cast iron obtained by isothermal quenching (Rm = 950-990 MPa, Rp0,2 = 720-770 MPa, A = 6,0-8,5 %).
Promising developments
Traditional ductile cast irons usage is very appropriate for obtaining of responsible (including those that work under vibration, shock and shock-cyclic loads) parts of military equipment, cars, agricultural machinery, vehicles, engines, drives, compressors, pumps, pipelines, railways in exchange for much more expensive, in terms of manufacturing cost, rolled parts, forged billets and steel castings. The department has the following developments:
1. Resource-saving technology of cast iron modifying in pre-crystallization period. Ensures production of ductile cast iron thin-walled castings (with a minimum wall thickness of 2-3 mm) in the as-cast state with increased amounts of spheroidal graphite inclusions (1200-1700 pcs./mm2) and ferrite (2-3 times), without chill and with increased in 1.5-2 times plasticity. Is better than world analogues.
2. A low-inertia gating system with a two-chamber flow reactor for cast iron melt modifying. Increases the magnesium transition degree from FeSiMg master alloys to cast iron by 30-50 %, allows to use a 1-15 mm polydisperse fraction of master alloy, increases the degree of reactor volume filling with a solid phase from 50 to 75 %, increases the castings yield, eliminates the influence of technological parameters fluctuations on ductile cast iron structure and properties in castings. Surpasses world analogues.
3. Ferritic ductile cast iron and its production technology. In the parts that are obtained in as-cast state it has a fine structure, more uniform increased values of strength indicators (Rm = 550-620 MPa, Rp0.2 = 420-500 MPa), plasticity (A = 11-17 %) and hardness, significantly better machinability. Surpasses world analogues.
4. Corrosion-resistant low-magnetic austenitic cast iron. Meets the requirements of NACA standards for materials in the hydrogen sulfide performance on the resistance to corrosion cracking in the formation fluid. These cast irons have cold resistance up to minus 80 °C and increased corrosion resistance in sea water, iodine-bromine water and in other aggressive environments (solutions of aluminum chloride, calcium chloride, iron sulphate, ammonium sulphate etc). The service life of products made of these cast irons is 10 times longer than that of common special Ce-B or Ti-Cu cast irons. Is better than world analogues.
Publications
Patents of Ukraine:
- a useful model UA80358 «Modifier for cast iron in-mold modifying» (2013);
- a useful model UA99434 «Alloy for cast iron modifying in a foundry mold» (2015);
- a useful model UA102534 «Ductile cast iron for thin-walled castings» (2015);
- a useful model UA137717 «Modifier for ductile cast iron obtaining» (2019);
- an invention UA126781 «Ductile cast iron» (2023).
Articles:
1. Bublikov V. B., et al. (2022). Development of technologies of high-plastic ductile cast irons of ferritic class obtaining. Metal and Casting of Ukraine, vol. 30, No 3 (330), p. 72-80. https://doi.org/10.15407/steelcast2022.03.072
2. Bublikov V. B., et al. (2021). Technology of thin-walled ductile cast iron castings obtaining in coated metal moulds with the use of in-mold melt modifying. Metal and Casting of Ukraine, Vol.29, №1, p.46-53. https://doi.org/10.15407/steelcast2021.01.046
3. Bublikov V. B., et al. (2020). Ductile cast iron with silicon and nickel strengthened a-solid solution. Metal and Casting of Ukraine, Vol. 28, №3, p. 63-68. https://doi.org/10.15407/steelcast2020.03.063
4. Bublikov V. B., et al. (2020). Silicon alloyed ductile cast iron and its application. Casting Processes, Vol. 139, No 1, p. 20-29. https://doi.org/10.15407/plit2020.01.020
5. Bublikov V. B., Bachynskyi Yu. D. (2018). Ductile cast iron: the progress of technologies, an improvement of properties. Metal and Casting of Ukraine, No. 7-8, p. 7-12.
6. Bublikov V. B., et al. (2017). FeSiMg master alloys effectiveness at in-mould modifying. Metal Science and Treatment of Metals, Vol. 84, No 4, p.3-9.
7. Bublikov V. B., et al. (2019). Features of structure formation and mechanical properties of ductile cast iron in castings obtained by casting in shell molds using «in-mold» process. Casting Processes, Vol. 133, No 1, p. 44-49.
8. Bublikov V. B., et al. (2019). Special ductile cast irons with increased complex of mechanical properties. Casting Processes, Vol. 134, No 2, p. 73-78.
9. Bublikov, V. B., Bachinskyi, Y. D., Berchuk, D. N., Yasinskyi, A. A., & Nesteruk, E. P. (2010). Mg7-FeSi Alloy Dissolution Kinetics in the In-Mould Process. In Key Engineering Materials (Vol. 457, pp. 476–480). Trans Tech Publications, Ltd. https://doi.org/10.4028/www.scientific.net/kem.457.476
