Obrabotka Metallov. 2016 no. 3(72)

ОБРАБОТКА МЕТАЛЛОВ № 3 (72) 2016 39 МАТЕРИАЛОВЕДЕНИЕ Abstract Three types of metal laminated composite materials consisting of alternating plates of durable and plastic steels are formed by explosive welding. In order to increase the structural strength indicators, the derived composite materials are heat treated. Compositions containing maraging steel are subjected to artificial aging for 3 hours at 490 °C. Compositions containing tool steel are quenched in oil at 880 °C and then tempered at 550 °C. The mechanical properties of the materials are determined by its structure. Carried out static and dynamic mechanical tests confirmed the positive effect of heat treatment on the properties of the layered composite materials, in spite of the diffusion zones formation in the structure. During heat treatment of multilayer materials, obtained by explosive welding of chrome-nickel austenitic steel and structural tool steel thin plates, an explicit gradient structure is formed, and characterized by the presence of several zones with different structure. An accelerate formation of these zones during heating contributes to the non-equilibrium structure of materials in the heat-affected zone of a width of about 100 μm, which is formed as a result of severe plastic deformation of dynamically interacting steel billets. The width of the diffusion zones along weld profile waves is derived from the different degrees of plastic deformation. It is established experimentally that the effect of the deformation and heat treatment processes on the nature of the hardening of chromium-nickel, maraging and tool steels differs sharply. The results of the microhardness measuring in the central areas of the plates indicate that chromium-nickel steel is hardened by explosive welding on 42%. In the soak process at 490 °C its microhardness is practically unchanged. Maraging steel conversely is undisposed to hardening during welding and is hardened on aging stage at 490 °C by 53 %. The mechanism of maraging steel hardening is due to the formation of intermetallic particles. The microhardness of the tool steel during explosion welding is increased by 32. Heat treatment allows to further raise the microhardness level of the tool steel by 48%. It has been shown experimentally that there is a difference in average 30 % of the stress limit values, compared with calculated values obtained by using the rule of mixtures. Difference in the level of the stress limit values is due to the work hardening that occurs during the dynamic interaction of steel billets. Keywords maraging steel, carbon steel, chrome-nickel stainless steel, explosive welding, laminated composite materials, heat treatment. DOI: 10.17212/1994-6309-2016-3-31-40 References 1. Entin R.I., Kurdyumov G.V. Puti povysheniya prochnosti i plastichnosti konstruktsionnykh stalei [Ways to improve the strength and ductility of structural steels]. Vestnik Akademii nauk SSSR – Herald of the Russian Academy of Science , 1967, no. 8, pp. 20–26. (In Russian) 2. Tushinskii L.I. Strukturnaya teoriya konstruktivnoi prochnosti materialov [The structural theory of constructive strength of materials]. Novosibirsk, NSTU Publ., 2004. 400 p. 3. Novikov I.I. Teoriya termicheskoi obrabotki metallov [The theory of heat treatment of metals]. Moscow, Metallurgiya Publ., 1986. 480 p. 4. BernshteinM.L., ZaimovskiiV.A.,KaputkinaL.M. Termomekhanicheskayaobrabotka stali [Thermomechanical processing of steel]. Moscow, Metallurgiya Publ., 480 p. 5. Lakhtin Yu.M., Arzamasov B.N. Khimiko-termicheskaya obrabotka metallov [Chemical heat treatment of metals]. Moscow, Metallurgiya Publ., 1985. 256 p. 6. Korzhov V.P., Kiiko V.M., Karpov M.I. Structure of multilayer microcomposite Ni/Al obtained by diffusion welding. Inorganic Materials: Applied Research , 2012, vol. 3, iss. 4, pp. 314–318. doi: 10.1134/S2075113312040107 7. Mizia R.E., Clark D.E., Glazoff M.V., Lister T.E., Trowbridge T.L. Optimizing the diffusion welding process for alloy 800H: thermodynamic, diffusion modeling, and experimental work. Metallurgical and Materials Transactions: A , 2013, vol. 44, iss. 1, suppl., pp. 154-161. doi: 10.1007/s11661-011-0991-6 8. Harach D.J., Vecchio K.S. Microstructure evolution in metal-intermetallic laminate (MIL) composites synthesized by reactive foil sintering in air. Metallurgical and material transaction: A , 2001, vol. 32, iss. 6, pp. 1493– 1505. doi: 10.1007/s11661-001-0237-0 9. Rohatgi A., Harach D.J., Vecchio K.S., Harvey K.P. Resistance-curve and fracture behavior of Ti-Al 3 Ti metallicintermetallic laminate (MIL) composites. Acta Materialia , 2003, vol. 51, iss. 10, pp. 2933–2957. doi: 10.1016/ S1359-6454(03)00108-3