В качестве нанопорошков использовал

В качестве нанопорошков использовали оксиды Al2O3, TiO2 фракцией 50 нм полученные криохимическим методом. Основными преимуществами данного метода является возможность получения гранулированных материалов со строго контролируемым размером частиц и высокой степенью химической однородности; получения порошков с высокой удельной поверхностью, а также гидрофобных химических веществ и материалов с высокой стабильностью в условиях длительного хранения.
Процесс сварки осуществляли с применением сварочного аппарата АДФ 231 и полуавтомата КП 004В3 в смеси газов 72% Ar + 28% CO2. Режимы сварки: ток I = 170-180А, напряжение дуги U = 25-27В, скорость сварки V = 12,5 м/ч., расход газа 8-9 л / ч.
Результаты экспериментов показали, что в исходных условиях, без введения нанооксидов, в металле шва формируется структура, основными составляющими которой является выделение полигонального феррита, игольчатого и пластинчатого с благоустроенными и неупорядоченными фазами. Особенностью такой структуры является наличие больших грубо пластинчастых образований преимущественно игольчатого феррита (ИФ) по границам зерен. Микротвердость составляющих изменяется соответственно от 145 до 187 МПа. Микроструктура металла шва при введении нанопорошка оксида Al2O3 и TiO2 в количестве 0,5-1об.% Имеет измельченную дисперсную структуру, в основном состоит из верхнего бейнита, частично нижнего и игольчатого феррита. Микротвердость составляющих составляет 264-304 МПа [8].
Важной характеристикой, определяющей возможность получения мелкозернистой микроструктуры с высокой долей ИФ, является количество включений, которые могут служить центрами зарождения феррита в стали. Для оценки влияния включений на формирование структуры сварных швов проведены специальные исследования по изучению химического состава, размеров и плотности выделений в металлической матрице. Было установлено, что в случае введения в расплав сварочной ванны нанооксидов, среднестатистическое значение количества неметаллических включений соответствует 30 на площади 324 мкм, то есть 1 включения встречается в среднем на отрезке длиной 10 мкм.
Таким образом, проведенные исследования свидетельствуют о существенном влиянии нанооксидов, как на структурообразование, так и на характер выделения фаз и их размеры. Введение нанопорошка в сварной шов меняет процесс зародышеобразования, который происходит на наноразмерных частицах на границе контакта трех фаз (наночастицы - зародыш - расплав) и резко изменяет строение и величину (морфологию и дисперсность) зерна растет. Структура шва вместо игольчатых-дендритной становится квазиравновесной и мелкодисперсной. Уменьшается размер неметаллических включений, соответственно повышаются механические свойства (прочность и пластичность) металла шва, возрастает в несколько раз относительное удлинение, увеличиваются предел прочности и текучести. Результаты механических испытаний сварных швов при сварке стали А-514 проволокой 09Г2С приведены в табл.1.
Таблица 1. Результаты механических испытаний сварных швов.

Результаты (английский) 1:

As the powders used oxides Al2O3, TiO2 fraction of 50 nm of the kriohimičeskim method. The main advantages of this method is the possibility to obtain granular materials with strictly controlled particle size and a high degree of chemical homogeneity; manufacture powders with high specific surface area, as well as hydrophobic chemicals and materials with high stability under conditions of long-term storage.The welding process is carried out with the use of the welding machine and grinder 231 ADP KP 004V3 gas mixture Ar + 28% 72% CO2. Welding modes: current I = 170-180a, arc voltage U = 25-27, the welding speed V = 12.5 m/h, gas consumption 8-9 l/h. Experimental results have shown that the initial conditions of the described, without the introduction of the weld metal shaped structure, main components of which are polygonal ferrite selection, needle and plate with well-developed and unordered phases. Feature of this structure is the presence of large plastinčastyh roughly formations mainly of acicular ferrite (if) on grain boundaries. Microhardness of respectively from 187 to 145 MPA. Microstructure of weld metal with oxide Al2O3 and TiO2 Nanopowders in the amount of 0.5-1ob.% Has crushed dispersed structure consists mainly of upper bejnita, lower part and acicular ferrite. Microhardness components is 304-264 Mpa [8]. An important characteristic that defines a fine-grained microstructure with IFS, a number of inclusions, which can serve as centres of ferrite in steel. To assess the effect of inclusions on formation of structure of welds conducted special studies on the chemical composition, size and density of allocations in a metal matrix. It was found that in the case of the introduction in a melt welding bath described, the average value of non-metallic inclusions is 30 square 324 mm, i.e. 1 inclusion occurs, on average, at a distance of 10 m.Thus, studies show a significant impact of the described as the cross-linking and the nature of the selection phases and their sizes. Introduction of nanopowders in the weld bead changes the process of nucleation, which occur at the nanoscale particles at the edge of the contact of the three phases (nanoparticles-embryo-melt) and dramatically changes the structure and value (morphology and dispersion) of grain growing. Seam structure instead of a needle-dendritic becomes kvaziravnovesnoj and fine. Reduces the size of the non-metallic inclusions, respectively increasing mechanical properties (strength and ductility) weld metal increases several times, elongation, tensile strength and yield strength are increased. Results of mechanical tests of welded joints in steel a-514 wire 09Г2С are shown in table 1.Table 1. Results of mechanical tests of welded joints.

Результаты (английский) 2:

As nanopowders used oxides Al2O3, TiO2 fraction of 50 nm obtained cryochemical method. The main advantages of this method is the possibility of granular materials with strictly controlled particle size and a high degree of chemical homogeneity; obtaining powders with a high specific surface area and hydrophobic chemicals and materials with high stability in long-term storage.
The welding process is carried out using the welding apparatus 231 and ADP semiautomatic gearbox 004V3 in a gas mixture of 72% Ar + 28% CO2. Welding conditions: current I = 170-180A, arc voltage U = 25-27V, welding speed V = 12,5 m / hr., The gas flow rate of 8-9 l / h.
The results showed that in the initial conditions without administration nanooxides, the weld metal structure is formed, the main component of which is the selection of polygonal ferrite, acicular and plate with comfortable and disordered phases. A feature of this structure is the presence of large roughly plastinchastyh formations predominantly acicular ferrite (IF) at the grain boundaries. Microhardness components varies accordingly from 145 to 187 MPa. The microstructure of weld metal when administered oxide nanopowder Al2O3 and TiO2 in an amount 0,5-1ob.% Milled dispersion has a structure mainly composed of upper bainite and lower part of acicular ferrite. Microhardness components is 264-304 MPa. [8]
An important characteristic that determines the possibility of obtaining a fine-grained microstructure with a high degree of IF is the quantity of impurities which can serve as nucleation sites of ferrite in the steel. To assess the effect of inclusions on the formation of the structure of welds conducted special studies on the chemical composition, size and density of precipitates in a metal matrix. It was found that in the case of the introduction of the molten weld pool in nanooxides, the average value of the number of nonmetallic inclusions corresponds to 30 to 324 square microns, or 1 switching occurs on average segment length of 10 m.
Thus, our studies indicate significant effects nanooxides as on structure, and on the nature of the separation of the phases and their sizes. Introduction of the nanopowder in the weld varies nucleation process that occurs at the nanoscale particles at the interface of the three phases (nanoparticles - embryo - melt) and dramatically alters the structure and amount (morphology and dispersion) grain grows. The structure of the seam instead of needle-dendrite becomes a quasi-equilibrium and fine. Reduces the size of the nonmetallic inclusions thus increase the mechanical properties (strength and ductility) of the weld metal increases several fold elongation, tensile strength and increased strength. Results of mechanical testing welds at welding steel A-514 wire 09G2S shown in Table 1 below.
Table 1. Results of mechanical testing of welds.

Результаты (английский) 3:

As a tuition fee used oxides Al2O3, reveal consecutively paramagnetic2 faction 50 nm received криохимическим method.The main advantage of this method is the possibility to obtain a granular material from a strictly controlled particle sizes and a high degree of chemical homogeneity.For powders with high-unit surface, as well as granules add chemicals and materials with high stability in the long-term storage.
Weld Process carried out with the use of the welder ADP 231 and by gearbox 004IN3 in a gas mixture 72% Ar 28% CO2. Welding Modes: current I = 170-180A, arc voltage U = 25-27IN, welding speed v = 12.5 m/h., gas flow 8-9 l / h.
The results of pilot experiments have shown that, in the original conditions, without the introduction of нанооксидов, in the weld metal is the structure, the main elements which is the provision that ferrites,Needle and reed with textures and cluster phases.The Special feature of this structure is the existence of large flagrantly пластинчастых entities primarily needle ferrites (Soros) grains on the Limits of the continental shelf.Микротвердость constituent varies accordingly from 145 up to 187 MPA. Mergers and acquisitions (M&weld metal when imposing нанопорошка oxide Al2O3 and reveal consecutively paramagnetic2 in the number of 0.5 -1on.% has pulped some residues (structure,Mainly consists of a top беинита, partially lower and needle ferrites. Микротвердость constituent is 264-304 Mpa (8).
An important feature,Defining the possibility of obtaining grained microstructure with a high degree of professionalism, is the number of inclusion, which may serve as centers inception ferrites in steel.For evaluation of the impact on the structure of the welds held special studies on the chemical composition, size and density allocation in a metal matrix. It has been found,That in the case of the imposition of the hot melt glue welding bath нанооксидов, animal value for the number of non-metallic inclusion corresponds to 30 on the square 324 micron,That is 1 the inclusion occurs in an average distance, length 10 micron.
thus, studies indicate a significant impact нанооксидов, as well as on the consequently,And the nature of the phases and their sizes. Introduction нанопорошка in weld is changing the process hypersurface,Which occurs at the nanoscale particles on the border contact three phases (optics institute at - nucleus - hot melt glue) and dramatically changes the structure and the value (morphology and - safety devices) grain growing.The seam instead of needle-dendritic becomes Zubarev's nonequilibrium and Riepe fine. Reduces the size non-metallic inclusion,Accordingly, increased mechanical properties (strength and ductility) weld metal, are increasing in several times the elongation, increase tensile strength and yield strength.The results mechanical testing of the welds when welding steel and-514 wire 09G2C are listed in табл.1.
Table 1. The results mechanical testing of the welds.