Nikulina A.A., Porechina А.A. et. al. 2020 Vol. 22 No. 2

OBRABOTKAMETALLOV Vol. 22 No. 2 2020 61 MATERIAL SCIENCE References 1. Gotal’skii Yu.N. Svarka raznorodnykh stalei [Dissimilar steels welding]. Kiev, Tekhnika Publ., 1981. 184 p. 2. Voronenko V.I. Iznosostoikie austenitnye vysokomargantsovistye stali [Wear-resistant austenitic high manga- nese steels]. Liteinoe proizvodstvo = Foundry. Technologies and Equipment , 1998, no. 1, pp. 19–22. Microstructural Features of Welded Railway Frogs formed by Flash Butt Welding and Pulse-Arc Cladding Aelita Nikulina 1, a,* , Alexandra Porechina 2, b , Sergey Khlebnikov 2, c , Zinaida Bataeva 3, d , Vladimir Potapov 4, e 1 Novosibirsk State Technical University, 20 Prospekt K. Marksa, Novosibirsk, 630073, Russian Federation 2 JSC “Novosibirsk switch plant”, 7 Aksenova st., Novosibirsk, 630025, Russian Federation 3 Siberian State University of Water Transport, 33 Schetinkina st., Novosibirsk, 630099, Russian Federation 4 Novosibirsk State Pedagogical University, 28 Viluiskaya st., Novosibirsk, 630126, Russian Federation a https://orcid.org/0000-0001-9249-2273, a.nikulina@corp.nstu.ru, b https://orcid.org/0000-0001-5925-6455, porechina13@mail.ru, c https://orcid.org/0000-0001-5231-6056, khsv0196@yandex.ru, d https://orcid.org/0000-0001-5027-6193, bataevazb@ngs.ru, e https://orcid.org/0000-0001-9461-2064, vm_potapov@mail.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2020 vol. 22 no. 2 pp. 53–62 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2020-22.2-53-62 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 05 February 2020 Revised: 12 March 2020 Accepted: 15 April 2020 Available online: 15 June 2020 Keywords : Flash Butt welding Impulse arc cladding Dissimilar steels Microstructure Welded Railway Frogs Acknowledgements The studies were performed using the equipment of the Common Use Center “Structure, mechanical and physical properties of materials” NSTU. ABSTRACT Introduction. Railway crosses (frogs) are important elements of the railway track. In the transition from detachable joints of crosses and rails to permanent connection using butt fl ash welding, the main problem is to obtain joints characterized by high fracture toughness. The work purpose is to increase the mechanical properties of railway frogs made by welding workpieces from Had fi eld steel and rail steel through intermediate alloyed inserts forming by cladding. Materials and methods. Combined constructions between workpieces made from high-carbon and high-manganese steels through an intermediate chromium-nickel insert are analyzed in the work. In the fi rst case, inserts were connected to the workpieces from high-carbon steel by fl ash butt welding. In the other case, inserts were formed by pulse-arc cladding of A7-IG wire on rail billets. Structural studies are carried out using light microscope and scanning electron microscope equipped with EDX. Microhardness measurements are made with Wolpert Group 402 MVD tester. To determine the strength characteristics, the resulting combined structures are tested according to the three-point bending scheme with the determination of the fracture load and the de fl ection. Results. It is established that in the joints obtained by pulse-arc cladding of A7-IG wire on rail steel a continuous martensitic layer, which is the main reason for the embrittlement of the joints made by fl ash butt welding does not appear. The austenite-martensite structure is formed as intermittent layers along the boundaries of dissimilar materials. The maximum microhardness level corresponding to martensitic zones is 680 HV. Three-point bending testing showed that structures in which the intermediate austenitic insert is formed by pulsed-arc cladding, the breaking load and the maximal de fl ection increased by about 15 % comparing with joints fully made by welding. For citation: Nikulina A.A., Porechina А .A., Khlebnikov S.V., Bataeva Z.B., Potapov V.M. Microstructural features of welded railway frogs formed by fl ash butt welding and pulse-arc cladding. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2020, vol. 22, no. 2, pp. 53–62. DOI: 10.17212/1994-6309-2020-22.2-53-62. (In Russian). ______ * Corresponding author Saprykina NataliaA., Ph.D. (Engineering), Associate Professor Yurga Institute of Technology, 26 Leningradskaya st., 652055,Yurga, Russian Federation Е -mail: nat_anat_sapr@mail.ru