An analysis of the influence of the ratio of alloying elements in the Ni–Al–Cr–W–Mo–Ta system on the resistance of the deposited metal to thermal fatigue is presented. The cumulative effect of alloying elements on the resistance of the deposited metal to the appearance of cracks in conditions of cyclic temperature changes in the range of 20–1150°C has been established. It is shown that, in the alloying system under consideration, the sensitivity of the metal to the formation of thermal fatigue cracks mainly depends on the amount of refractory elements that cause the formation of topologically close-packed (TCP) phases. The content in the deposited metal of 3.5 wt % tungsten, 3.0 wt % molybdenum, and 2.5 wt % tantalum does not cause fatigue cracks. The developed type of deposited metal provides a high level of thermal and oxidative wear resistance as compared to high-alloyed industrial nickel and cobalt alloys.

The behavior of the structure of abrasion-resistant alloys of the Fe – Cr – C – Mo – Ni – Ti – B system during electric arc cladding with introduction of ultrafine particles of titanium nitride into the welding pool in the composition of both the electrode and the filling powder wires is considered. The effect of titanium nitride on the hardness and wear resistance of the experimental clad alloys at normal and elevated temperatures is studied, and the values of the operating properties of the alloys are compared to the respective properties of the commercial counterparts.

It is shown that the introduction of micro-sized particles of refractory compounds TiB, ZrB, CeO in the composition of the filler of the composite wire (CW) contributes to an increase in the quality of mass transfer of metal in the welding arc. It was found that under the influence of particles of the considered components, melting components of the CW filler, heterogeneous in terms of thermophysical properties, are more actively formed into a metal drop, and its overheating decreases. This helps to improve the quality of transfer of the electrode metal in the welding arc and to increase the conversion factors of alloying elements into the weld metal.

The studied GMAW processes - splitting the electrode into two wires, oscillation of the electrode, and cooling the weld pool metal with filler wire - reduce the arc thermal impact on the nanoparticles and improve their mass transfer into the solidifying metal. The nanoparticles in the wire fillers are recommended to be within 0.3-0.6 wt.%. Surfacing with two composite wires containing WC nanoparticles improves the properties of metal with a Ni-3 Al -based matrix at temperatures within 1000-1200 degrees C. WC particles influence the composite metal formation, initiating precipitation from the gamma + gamma' solid solutions of strengthening phases in the form of inter-metallides of (Zr,Ta,W)C type and ZrC carbides. The surfacing process with oscillation of the electrode flux-cored wire with TiCN particles improves the thermal and plastic resistance of the metal, with a matrix of the C-Fe-Cr-Ni-Mo-Ti-N system at temperatures within 750-950 C. The composite metal with fine grains is formed under the influence of nucleation centres, in the form of TiCN nanoparticle clusters. The filler flux-cored wire with ultra-disperse TiN particles introduced in the weld pool, improves the resistance of deposited metal of the Fe-C-Cr-Mo-Ni-B system to abrasive wear at 500 C. TiN particles initiate precipitation from the deposited metal matrix of strengthening phases in the form of (Ti, Mo)C1-x carbides that are 1 similar to 4 mu m in size. In conjunction with additional cooling of the melt near the solidification front, this helps to form the MMC structure in the melt.

Special features of structure and phase formation in deposited metal based on alloyed Ni 3 Al nickel aluminide formed due to high-gradient crystallization under the conditions of the thermal cycle of arc surfacing are studied. The effect of microalloying with ultrafine WC carbides on the resistance to thermal fatigue and plastic straining at elevated temperatures (up to 1200°C) is considered.

E. N. Eremin, A. S. Losev, S. A. Borodikhin, A. E. Matalasova, I. A. Ponomarev. Using thermal treatment for hardening corrosion-resistant coatings surfaced with a flux-cored wire containing BN-TiB 2 -ZrB 2 complex V. I. Kuznetsov, O. A. Sharikov. A method of processing mechanical mixtures using vortex set of deep separation G. N. Sokolov, A. A. Artemev, Yu. N. Dubtsov, E. N. Eremin, V. B. Litvinenko-Arkov, A. S. Losev. The influence of nitrogen and titanium carbonitride particles on structure and properties of metal Fe-C-Cr-Ni-Mo system deposited by flux wire

The influence of nitrogen and titanium carbonitride particles on the structure and properties of high-chromium steel deposited by flux cored wire has been studied. It has been shown that the quality formation of the deposited metal and pore absence in it are achieved with nitrogen concentration in wire filler no more than 0,32 WT %. It has been found that in adding titanium carbonitride particles from 0,2 to 0,6 WT % to wire filler the effect of deposited Fe-C-Cr-Ni-Mo-N system metal modification is implemented and its operational properties increase. The developed flux cored wire has been recommended for oil and gas equipment surfacing.

The correlation was established between the transfer effervescive of alloys into the deposited Ni-Cr-Mo-Nb metal system, the flux composition and the conditions for stable arcing. The combined influence of arc voltage, the electrode dip angle and the distance between the electrode wires on the deposited metal formation was assessed. The twin wire dip angle range (10-30 degrees) was revealed to ensure high-quality deposited metal formation with minimal share (30 %) of the base metal. The formed chemically homogeneous structure of the alloyed gamma-solid solution contains small (up to 5 vol. %) amount of intermetallic phases which ensures the required mechanical properties.

The algorithm and description of the AlMe-WireLaB software for the computer-assisted design of flux-cored wires are introduced. The software functionality is illustrated with the selection of the components for the flux-cored wire, ensuring the acquisition of the deposited metal of the Fe-Cr-C-Mo-Ni-Ti-B system. It is demonstrated that the developed software enables the technologically reliable flux-cored wire to be designed for surfacing, resulting in a metal of an ordered composition.

Electrode composite wire (CW) was used for argon-arc surfacing of a thermal-resisting nickel aluminide-based alloy (Ni-Al-Cr-W-Mo-Ta system) on the butt-end surface of the non-water-cooled piercing mandrel. It was shown that multipassing surfacing forms a defect-free deposited metal based on the gamma'-Ni3Al phase of various structural origins. Using high-temperature sclerometry and thermal fatigue testing methods, the metal deposited with CW containing ultrafine particle of 0.3-0.4 % wt. WC carbide features increased resistance to thermal and force effects at temperatures up to 1200 degrees C.

A wear-resistant composite coating process with electroslag surfacing using a current-supplying solidification mould was developed. The structure and properties of coatings from flux-cored wire deposited alloys with refractory micro-particles of titanium diboride, TiB2, and nano-sized particles of titanium carbonitride, TiCN, were studied. Special features of the elasto-plastic deformation of composite alloys’constituents were studied with sclerometry.

Metallography reveals the correlations between the amount, size, and morphology of ultrafine particles in welding materials (flux-cored and composite wires, coated electrodes, and agglomerated fluxes), as well as the processes of formation of exogenous crystallization centers in the welding pool that facilitate the structure modification and promotion of processing and working properties of deposited metal. The phenomenological model of the nucleation on ultrafine exogenous refractory chemical clusters is developed on the basis of the experimental data and on the existing view of the kinetics of fast physicochemical processes in the welding fire point.

Electromechanical hardening of applied surface layers of thermostable and wear-resistant iron and ferronickel alloys modified by ultrafine TiCN and WC particles is considered; the ferronickel alloy contains γ′-Ni 3 Al phase. The dependence of the microhardness and the depth of the hardened layer on the current is established.

The composite wire compound calculation methods were considered, factoring stoichiometric ratio values of the elements of the intermetallic γ'-Ni3Al, draft, elongation and compaction of the filling’s components as well as the values of alloy transfer effervescive. It is found that during argon-arc surfacing the components of the composite wire’s filling and coating are melting uniformly at the welding current density from 30 to 50 A/mm2. The correlation was established between the composition, the construction of the composite wire for arc welding and surfacing and the structure of Ni3Al based deposited metal. It is shown that the developed composite wire provides the deposited metal with the structure of nickel aluminide economically alloyed with wolfram, molybdenum, tantalum and chrome.

It is shown that introduction into electrodes and agglomerated fluxes for arc welding of ultrafine refractory compound components facilitates an increase in low-carbon steel metal structure cold resistance.

The structure and properties of Fe and Ni3Al weld metals doped with TiCN and WC nanoparticles are investigated via optical and scanning electron microscopy, X-ray spectroscopic microanalysis, and fatigue life and abrasive wear tests.

The structure of a welded joint obtained by argon-arc welding with the use of a composite electrode wire of a Ni 3 Al-base alloy after directed crystallization is studied. It is shown that the use of composite electrode wire containing nanoparticles of tungsten carbide for argon-arc welding promotes formation of a quality weld metal and a defect-free transition zone between the latter and the directedly crystallized alloy based on Ni 3 Al.

Представлена методика расчета состава электродной композиционной проволоки (КП), обеспечивающая с достаточной точностью заданный химический состав сварных швов и наплавленного металла на основе γ-Ni3Al. Методика основана на учете величин стехиометрического соотношения элементов, входящих в интерметаллическое соединение Ni3Al, степени обжатия, удлинения и уплотнения компонентов наполнителя, а также значений коэффициента перехода легирующих элементов.

Разработан способ получения износостойких композиционных покрытий электрошлаковой наплавкой с использованием токоподводящего кристаллизатора и порошковых проволок, содержащих тугоплавкие частицы диборида титана TiB2. Изучены термические условия формирования тонкого слоя износостойкого наплавленного металла и выявлена кинетика перехода в него тугоплавких микрочастиц из наполнителя порошковой проволоки.