Zharikov S. Perfection of self-shielding flux-cored wire for surfacing of dies by introducing exothermic mixture into filler

The object of research - the process of hardening of punching tools, performing the cutting operation in the cold state, surfacing its working superficies self-shielding flux-cored wire (SFW) with an exothermic mixture. Subject of research - welding and technological properties of the SFW with an exothermic mixture. Purpose - to increase the efficiency of the surfacing die tools by introducing an exothermic mixture of the SFW. Novelty - research methods: electron microscopy, spectral, micro X-ray spectral, metallographic, mathematical design of experiments and statistical processing of results. The composition of SFW with an exothermic mixture is proposed, which increases the specific heat per unit time and the heating temperature of the core, which reduces the lag melting core from the sheath; proven that the use of the exothermic mixture consisting flux-cored wire creates thermal conditions which uniform distribution of alloying elements in the deposited metal is allow to obtain, the amount of non-metallic inclusions and their shape is reduce, the depth of penetration is decrease, that provides chemical homogeneity of the deposited metal and achieving a given chemical composition already in the second layer; shown that the complex introduction of the SFW exothermic mixture which provides uniform melting of the core and the sheath of the wire, and compositions metal carbonates, which guarantees the security nature of the atmosphere in a wide range of temperatures, delivers reliable protection of the metal droplets and baths, low gas content in the metal and the necessary degree of alloying. The research results of the proposed composition of the SFW with exothermic mixture for surfacing cutting dies passed approbation in production conditions JSC "EMSS" and showed an increase of the resistance of the tool by 45...50%.