Effect of electric parameters of arc surfacing using self-shielding flux-cored wires on process stability and base metal penetration was investigated. The experiments were carried out with computer registration of electric parameters of surfacing. The results of oscillogram processing were used for plotting of Iw and Uw diagrams with outlined areas of stable process of surfacing, short circuits and arc extinctions. Coefficient of process instability γ was derived from received real parameters of arc surfacing using flux-cored wire. It is determined that voltage has the largest effect on stability indices and its rise improves process stability. Effect of modes of surfacing on penetration and portion of base metal in the deposited metal was investigated. 3D chart was plotted on estimation results. An area of optimum modes, providing sufficient stability of the process at minimum penetration and good formation of deposited beads, is outlined. K e y w o r d s : arc surfacing, flux-cored wire, stability of surfacing process, instability coefficient, base metal penetration, portion of base metalNecessary composition of the deposited metal in multilayer arc surfacing can be obtained only in the third or fourth layer [1] due to its mixing with the base metal. Five layers as minimum should be surfaced, if machining of part is necessary after surfacing. The problem becomes more complicated due to the fact that rise of thickness of the deposited layer promotes for growth of residual shearing stresses and, simultaneously, increases the possibility of appearance in the deposited layer of different type defects, which reduce its service properties, including fatigue life under cyclic loading [2,3]. Thus, one of the most important characteristics for surfacing is a portion of base metal (PBM) in the deposited metal proportional to base metal penetration other things equal. Reduction of the base metal penetration not only decreases consumption of expensive consumables, but improves quality and service properties of the parts to be surfaced.Aim of the present work is a study of effect of electric parameters of flux-cored arc surfacing, in particular, stability of these indices on characteristics of the base metal penetration.Consumables and equipment. Self-shielding flux-cored wire PP-AN130 was used for investigations. It provides for production of surfaced metal of tool steel 25Kh5FMS type. Gas-slagforming system of the flux-cored wire, which would provide the best welding-technological properties, was preliminary selected. Four selfshielding flux-cored wires PP-AN130 of 2 mm diameter having different systems of gas-slagforming components, namely СаO + TiO 2 + MgO + CaF 2 + Al 2 O 3 (wire with reference designation PP-AN130-1); СаO + MgO + CaF 2 + Al 2 O 3 (PP-AN130-2); СаO + CaF 2 + Al 2 O 3 (PP-AN130-3); СаO + CaF 2 + Al 2 O 3 + starch (PP-AN130-4), were manufactured for this purpose.Expert estimation (5 examiners) of the welding-technological properties of all four wire types (nature of metal transfer, slag coating of the ...

On the basis of portable computer and advanced software the information-and-measuring system was developed, which is intended to investigate the peculiarities and next automation of the arc surfacing processes. In the surfacing installation equipped with the developed computer information-and-measuring system (CIMS) it is possible to carry out experimental investigation of the influence of surfacing method, diameter or cross section of the used electrode material on its welding and technological characteristics and quality of the deposited beads and layers formation with a high degree of accuracy and reliability. CIMS with accumulation of databases on technologies of arc surfacing of different parts can serve as a basis for creation of systems of automatic control of arc surfacing processes. 3 Ref., 1 Table, 4 Figures. K e y w o r d s :Figure 3. Diagrams of F pu and F pvp functions depending on average values of current and voltage in open-arc surfacing using self-shielding flux-cored wire of 1.8 mm diameterFigure 4. Range of open-arc surfacing modes with flux-cored wire of 1.8 mm diameter, where the approximation error in arc voltage and current during surfacing does not exceed ±1 V and ±10 A, respectively

Цель. Исследование физических свойств составляющих биологических тканей и их роли в процессе электрической сварки мягких биологических тканей, а также измерение температуры в зоне электросварки. Материалы и методы. Исследования провели с использованием созданной системы для измерения температуры, состоящей из усилителя термо-ЭДС, внешнего модуля АЦП Е14-440 “Л-Кард”, ноутбука с программным обеспечением “PowerGraph”. Использовали также биполярный электрохирургический зажим и ВЧ-электрокоагулятор ЕК-300М1. Для имеющегося при сварке биологических тканей диапазона температур 40 – 200 °С выбраны термопары К–типа диаметром 70 мкм. Результаты. Проведенные исследования позволили установить, что сопротивление электролитов уменьшается, а проводимость - увеличивается с повышением температуры. Это объясняется тем, что с повышением температуры для слабых растворов увеличивается их диссоциация и, следовательно, число положительных и отрицательных ионов. Электропроводность цельных органов в 2 - 5 раз ниже, чем электропроводность биологических жидкостей. Поэтому при «полном» обезвоживании ткань практически теряет электропроводность, тепло в ней перестает выделяться и происходит резкое падение напряжения, силы тока и сопротивления, что предотвращает глубокие деструктивные изменения мягких тканей в зоне электросварки. Эти данные получены нами в процессе выполнения эксперимента по изучению температурных режимов тканей кишечника, мышечной ткани, легкого и печени. Выводы. Данными, полученными в ходе выполнения эксперимента, доказана безопасность высокочастотной электросварки мягких тканей в пределах температурных режимов от 45 до 95 °С без явлений некроза и обугливания.

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