No abstract

Abstract. Method of forecasting thermodynamic properties of melts from the liquidus coordinates ofphase diagram in the area of equilibrium of a solid component with a solution is presented. Gibbs mixingenergies in the binary boundary MgO – Al2O3, MgO – SiO2, MgO – CaF2, Al2O3 – SiO2, Al2O3 – CaF2,SiO2 – CaF2 systems are calculated by this method.Keywords: a activity, coordinates of liquidus, the diagrams of the state, the double and triple systems, theequalization of Hauffe-Wagner, the melts, the partial molar energy of Gibbs, the thermodynamics properties.

An effective means for improvement of technical and economic indicators of EAF DC are graphitized cored electrodes, designed at the E.O. Paton Electric Welding Institute. The research works of the first stage, carried out in the industrial furnaces of the type EAF DC-12, showed that the arc of the cored electrode is always maintained in the center of the electrode, a stable electric mode of melting is provided on long arcs and low voltages of the power source. It was established that the voltage in the near cathode area, as well as the range of current and voltage pulsation of the cored electrode arc is significantly lower than in the standard (monolithic) graphitized electrode. These factors determined the saving of active energy, reduction of reactive power losses, increase in cos φ and reduction of the furnace noise level

Розглянуто методику прогнозування термодинамічних властивостей розплавів ізкоординат ліквідусу діаграми стану в області рівноваг твердий компонент – розчин, заякою розраховані енергії змішування Гіббса в подвійних системах MgO – Al2O3, MgO – SiO2,MgO – CaF2, Al2O3 – SiO2, Al2O3 – CaF2, SiO2 – CaF2. Для областей рівноваги квазібінарнасполука (MgAl2O4, Mg2SiO4, Al6Si2O13) – рідкий розчин при розрахунках використанорівняння Хауффе–Вагнера. Одержані дані узгоджуються з літературними. Значні від’ємнізначення енергій Гіббса змішування характерні для систем MgO – Al2O3, MgO – SiO2, щопідтверджується утворенням у цих системах стабільних сполук. Установлено, щорозроблена методика може бути застосована для складних в експериментальномувідношенні систем і дозволяє отримати велику кількість термодинамічних даних.Ключові слова: активність, діаграми стану, координати ліквідуса, парціальна мольнаенергія Гіббса, подвійні оксидно-фторидні системи, розплави, термодинамічні властивості.

Cored wires are used in numerous welding processes with or without external gas or flux shielding. Submerged arc welding (SAW) with cored wires, seamed or seamless, for joining mild and low alloyed steel grades is a technique that has demonstrated clear advantages during the three last decades. Ever since its invention, the SAW process has evolved with one main goal: to combine quality with productivity. With low alloy wires, the benefits have already been clearly demonstrated and widely exploited. However, little has been written on SAW and cladding with cored wires for corrosion or heat resisting applications. Its extension to high alloy compositions brings corresponding benefits and adds some specific and unique features. This paper focuses on consumable specificities and on the quality and productivity features of SAW with CRA (corrosion resistant alloy) cored wires. It describes the potential as well as the limitations of this technique. Cored wires are now used for submerged arc welding of almost all stainless steels ranging from soft martensitic to super-duplex, and for a series of nickel base compositions as well as for cladding cobalt base alloys. Examples of industrial applications with austenitic, duplex, martensitic and heat resisting stainless steels are given to illustrate the potential of the cored wire solution. 13 Ref., 4 Tables , 25 Figures.