Obrabotka Metallov. 2016 no. 3(72)

ОБРАБОТКА МЕТАЛЛОВ № 3 (72) 2016 59 МАТЕРИАЛОВЕДЕНИЕ phase steels / M.D. Zhang, J. Hu, W.Q. Cao, H. Dong // Materials Science & Engineering: A. – 2014. – Vol. 618. – P. 168–175. – doi: http://dx.doi.org/10.1016/j. msea.2014.08.073. 19. Goto S., Kami C., Kawamura S. Effect of alloy- ing elements and hot-rolling conditions on microstruc- ture of bainitic-ferrite/martensite dual phase steel with high toughness // Materials Science & Engineering: A. – 2015. – Vol. 648. – P. 436–442. – doi: 10.1016/j. msea.2015.09.093. 20. Nanostructured/ultrafine multiphase steel with enhanced ductility obtained by mechanical alloying and spark plasma sintering of powders / C. Menapace, I. Lonardelli, M. Tait, A. Molinari // Materials Science and Engineering: A. – 2009. – Vol. 517. – P. 1–7. – doi: 10.1016/j.msea.2009.03.021. 21. Munir Z.A., Anselmi-Tamburini U. The effect of electric field and pressure on the synthesis and consoli- dation of materials: a review of the spark plasma sinter- ing method // Journal of Materials Science. – 2006. – Vol. 41. – P. 763–777. – doi: 10.1007/s10853-006-6555-2. 22. Mariappan R., Kumaran S., Srinivasa Rao T. Ef- fect of sintering atmosphere on structure and properties of austeno-ferritic stainless steels // Materials Science and Engineering: A. – 2009. – Vol. 517. – P. 328–333. 23. Activated sintering of P/M duplex stainless steel powders / J. Kaziora, M. Nykiel, T. Pieczonka, T. Mar- cu Puscas, A. Molinari // Journal of Materials Process- ing Technology. – 2004. – Vol. 157–158. – P. 712–717. – doi: 10.1016/j.jmatprotec.2004.07.140. 24. Simchi A., Rota A., Imgrund P. An investigation on the sintering behavior of 316L and 17-4PH stainless steel powders for graded composites // Materials Science and Engineering: A. – 2006. – Vol. 424. – P. 282–289. – doi: 10.1016/j.msea.2006.03.032. 25. Райченко А.И. Основы процесса спекания порошков пропусканием электрического тока. – М.: Металлургия, 1987. – 128 с. 26. Omori M. Sintering, consolidation, reaction and crystal growth by the spark plasma system (SPS) // Ma- terials Science and Engineering: A. – 2000. – Vol. 287. – P. 183–188. – doi: 10.1016/S0921-5093(00)00773-5. OBRABOTKAMETALLOV (METAL WORKING AND MATERIAL SCIENCE) N 3 (72), July – September 2016, Pages 52–61 Formation of heterogeneous iron-carbon alloys structure by sintering of dissimilar steels particles Nikulina A.A. , Ph.D. (Engineering), Associate Professor, e-mail: a.nikulina@corp.nstu.ru Novosibirsk State Technical University, 20 Prospect K. Marksa, Novosibirsk, 630073, Russian Federation Abstract The objective of the study was to investigate the relationship between the microstructure of the compositions and the sintering conditions. Spark plasma sintering of dissimilar steels particles (Fe-0.8C and Fe-0.12C-18Cr-10Ni-1Ti with pearlite and austenite structures, respectively) is implemented to form heterophase iron-carbon alloys. Several sintering conditions with different temperature (1000 and 1100  C) and sintering time (5 to 25 minutes) are used. All obtained compositions are characterized by the absence of pores. Correlation of the heterogeneous microvolumes is close to 1:1. The main methods of structural research in the work are light microscopy and scanning electron microscopy. Microhardness testing is also carried out. The experimental results presented in the study clearly show that basic structural components in the obtained compositions are austenite, pearlite, ferrite, martensite, as well as chromium carbides. It is found that in the zones of interaction between heterogeneous particles the transitional chemical composition areas are formed. The chromium content reaches 6…8 % wt. and nickel – 2…3 % wt. in these areas. The maximum thickness of such areas at the sintering temperature of 1000 °C is less than 10 microns and at 1100 °C its width reaches 20 micron. This chemical composition of the intermediate areas leads to the appearance of austenitic-martensitic structure after cooling with microhardness level about 600…900 HV. Keywords spark plasma sintering, microstructure, pearlite, martensite, austenite, dissimilar steels, structural research. DOI: 10.17212/1994-6309-2016-3-52-61