Steel Penetration Research Articles

The Influence of Welding Technique With Variation of Current on Surface Defects and Penetration of ST40 Steel

One of the connection of one place starting from several materials or materials that are solid is one of the welding methods, as for the factors that can affect the quality of the weld results which include the process of tools and materials to be used, welding direction, welding electrode movement patterns, in order to use and select electrodes. In this study ST 40 steel plate, testing was carried out with 3 specimens using U and zigzag movement patterns and the direction of welding used back and forth. variations in electric current used are 40 A, 60 A, 80 A. This study has the aim of influencing welding techniques using current variations. The test results that the welding process using welding techniques consisting of movement patterns, welding direction and welding time does not affect the weld defects in the welding results. Welds defects that occur due to variations in the current used

Corrosion mechanism and microstructure evolution of industrial used Al2O3-ZrO2-C slide plates

Slide plates are one of the most important functional refractories that control the flow of molten steel from the steel ladle to the tundish. In order to improve the service performance of slide plates and accelerate continuous production of the steel industry, a detailed post-mortem analysis was necessary. In this study, the corrosion behaviors of the high-temperature heated Al2O3-ZrO2-C slide plate used one heat for a 200 tons steel ladle in industry were investigated. The results showed that the thermo-mechanical properties' mismatch led the formation of radial cracks, which was the main factor limiting the service life of the slide plates. Besides, corrosion microstructure revealed the dissociation of mullite-zirconia aggregates and the loss of graphite provided a channel for the penetration of molten steel. The penetration of molten steel could react with Al2O3 in the slide plates, which accelerated corrosion in the early stage and formed a composite spinel layer in the later stage to block corrosion. Also, acicular CaAl12O19 was formed behind the composite spinel layer, further blocking the penetration of molten steel. Furthermore, the ZrO2 from mullite-zirconia had an interlocking structure to prevent corrosion. Finally, the content and viscosity of the liquid phase at different positions of the used slide plates were calculated, which indicated that the area near the casting hole had more liquid phase and lower viscosity. This would further optimize the service performance of the slide plates.

Degradation mechanism of MgO–MgAl2O4 dual-phase refractory in contact with the automobile gear steel SCr420H with Si–Mn, Al and Ce–Al deoxidation

The current research, the degradation mechanism of MgO–MgAl2O4 dual-phase crucibles in contact with steel SCr420H with Si–Mn, Al, and Ce–Al deoxidation was investigated using a laboratory steelmaking experiment at 1873 K. The refractory interface in contact with the steel and inclusions was analysed using SEM and EPMA. In the case of Si–Mn deoxidation, the refractory's MgO phase was initially attacked by the dissolved Si, resulting in its transformation into the 2MgO–SiO2 phase, as confirmed by thermodynamic calculations. In the case of Al deoxidation, the reaction between the dissolved Al and the refractory had a significant effect on the increase in Mg concentration and MgAl2O4 inclusions. Refractory degradation was suppressed because the MgAl2O4 phase was an equilibrium phase based on thermodynamic consideration. The distribution of the MgAl2O4 phase in the refractory hindered the degradation reaction. The primary degradation mechanism in the case of Al deoxidation was steel penetration. In Ce–Al deoxidation, both Ce and Al were involved in refractory degradation. During this process, the MgO phase reacted with the dissolved Al, leading to its transformation into the MgAl2O4 phase, which was subsequently modified to the Ce–Al–O phase. Additionally, the MgAl2O4 phase was directly denatured into the Ce–Al–O phase.

Computational evaluation of assembly technique influence on ballistic performance of a bullet – non-linear relation between méplat size and the drag coefficient

The continuous development of production and assembly techniques gives rise to the idea of following a new approach in the small-arms ammunition design process. Commonly used intermediate cartridges were designed over 60 years ago, and their construction and assembly processes are not significantly different than what was available almost a century ago. Along with the recent development of individual protection devices and with the general availability of modern ballistic plates utilized in plate carriers type of individual armor, it sparks the necessity of designing a new, intermediate cartridge, using new assembly and technology methods. The vital aspect of the ammunition design process is a determination of the materials utilized in bullet elements and its assembly method. Therefore, there is a necessity of evaluating if different assembly techniques can provide the improved ballistic performance of a bullet. The paper includes a comparison of two differently assembled projectiles with steel penetrators: a standard Full Metal Jacket and a reverse-drawn Semi-Jacketed bullet. The designs were evaluated in terms of their external ballistic performance for specific initial conditions using 2D Computational Fluid Dynamics simulations and, separately, with a semi-empirical method. The paper aimed to assess the influence of the assembly method on the bullet’s external ballistic performance. Both calculations revealed a nonlinear relation between the projectile méplat diameter and the coefficient of drag, which indicates a limit where the méplat size reduction is beneficial. The results implicate a perspective bullet construction that would provide the user with better external ballistic performance, more consistent and precise than a standard Full Metal Jacket design.

Analysis of corrosion fatigue steel strength of pump rods for oil wells

Purpose is to perform analysis of corrosion durability (fatigue) of pump rod materials in terms of various chemically active simulation environments, and study influence of economically modified rare-earth impurity on corrosion fatigue strength of pump rod materials. Methods. 40 and 20N2M steel grades have been applied as well as experimental steel (ES). Steel of the conditinal ES grade has been melted within a pilot site of Institute of Electric Welding Named after E.O. Paton of the National Academy of Sciences of Ukraine. The steel was alloyed economically by means of a micro impurity of a rare-earth element (REE) being 0.03% of cerium; in addition, it contained comparatively low concentration of sulfur and phosphorus as well as minor concentration of dissolved hydrogen. The following has been used as simulation environments: 1) NACE environment (i.e. 5% NaCl solution which contained 0.5% СН3СООН, and saturated H2S; t = 22 ± 2°C; pH = 3.8-4.0); 2) 3% NaCl solution without hydrogen sulphide. Once every day, the environment was replaced to oxygenate it up to 8-10 mg/l concentration. Findings. Stability against sulfide stress-corrosion cracking (SSCC), hydrogen initiated cracking (HIC), and corrosion fatigue of steel of deep pump rods for oil industry has been studied. It has been defined that the experimental steel, modified economically by means of micro impurities of a REE, meets NACE MR0175-96 standard in terms of chemical composition as well as strength; in turn, 20N2M and 40 steel grades have high resistance neither to SSCC (threshold stresses are < 0.8 s) nor to corrosion fatigue attack; moreover, steel grade 40 has demonstrated low resistance to HIC (CLR > 6% and CTR > 3%). Originality. It has been identified that corrosion fatigue attack results from hydrogen penetration of steel initiating its cracking and hence destruction under the effect of alternating loads accelerated by the action of corrosive environment. Further, surface micro destructions, influenced by micro stresses, transform into large discontinuities and cracks with following macro destructions. Practical implications. It has been proved that high resistance to corrosion cracking can be achieved by means of refining of pump-rod steel of ferrite and perlite type using metallurgical methods, i.e. 0.01-0.03% REE microalloying.

Physical design of photon-counting mode γ-ray large object radiation imaging system.

The detectors of existing large object radiation imaging systems generally work under current-integration mode and cannot distinguish effective signals of unreacted photons from interfering signals of electronic noise and scattered photons, therefore, resulting in image quality deterioration. This study aims to design a new photon-counting mode γ-ray large object radiation imaging system. Therefore, interfering signals with lower energy than effective signals can be eliminated by energy analysis. In addition, the system enables to work properly even under 30∼300Ci Co-60 intensity. Based on the physical analysis of the system, the design requirements are listed. Following the requirements, the best-performing photon-counting detector based on LYSO and SiPM is used in the system. ZP-SK and (ZP)2-SK filter circuits are designed for Co-60 radiation imaging system with the highest intensity of 100Ci and 300Ci, respectively. Then, a voltage comparator and an FPGA are followed to realize the function of energy analysis and photon counting. The proposed technical solution can improve the Steel Penetration (SP) by at least 60∼70 mmFe compared with the existing current-integration system, which is equivalent to the improvement obtained by increasing the intensity of the radioactive source more than 13 to 20 times. This study demonstrates the advantages of applying the new photon-counting mode γ-ray large object radiation imaging system to improve the radiation image quality and the penetration ability, which will have enormous potential for future applications.

Effect of Cerium on the Interaction between a Si–Mn‐Killed Steel and a MgO‐Based Refractory

Herein, the contact angle between a Si–Mn-killed steel and MgO-based refractory is measured in a reduction atmosphere at 1853 K using the sessile drop method. As the cerium content in the steel increases from 0 to 0.0450 wt%, the initial contact angle between the steel and the refractory slightly increases from 136° to 138°, the equilibrium contact angle decreases from 131° to 124°, and the steel surface tension reduces from 1.756 to 1.624 N m−1. Cerium in the steel retards the formation of Mg–Si–O oxide on the steel drop surface. A higher cerium content promotes the chemical reaction, resulting in a decrease in the contact angle. The cerium addition leads to an increase in the steel–refractory reaction depth. With an increase in cerium in the steel, the meniscus contact angle between the steel and the micropore in the refractory increases. Consequently, the lower driving force of steel penetrating into the refractory causes the reduction of steel penetration into the refractory.

Chemical Interactions of Molten Steel with (U-Zr-O) Corium: Main Outcomes of the CORDEB Program

One of the strategies to mitigate the consequences of a severe accident is to stop the progression of molten materials (corium) within the vessel by external cooling of the vessel. This strategy is called in-vessel retention (IVR). The safety demonstration of IVR requires the accurate evaluation of the thermal load imposed on the internal surface of the vessel by the corium debris. During the progression of the accident, solid debris may be generated initially in the lower plenum because of fragmentation in water and, after melting of those debris, a (possibly stratified) molten pool would be formed. The consequences of the thermal and chemical interactions of the corium with the vessel are difficult to predict because there are still uncertainties on the application of existing results to models for reactor cases. These include scaling effects of course, but also the influence of transient processes occurring simultaneously: oxidation, dissolution, melt progression and/or stratification. In order to be able to predict the heat fluxes through the RPV wall, it is necessary to establish an overall view of the possible transient evolutions of corium and determine which are the most probable ’steady-state’ corium configurations after debris melting. The CORDEB program studies corium phenomena taking place at different stages of molten pool formation in the reactor vessel. It may be considered as an investigation of corium configurations that were not considered in previous programs such as the OECD RASPLAV and MASCA programs. All experiments within the program are carried out in the Rasplav tests facility of NITI, using the technology of induction melting in a cold crucible. This program is co-funded by IRSN, EDF, AREVA and CEA in the frame of the CPSIN agreement. This paper presents the main conclusions drawn from CORDEB tests, both for phenomenological knowledge and for transposition to reactor situations. Quantitative elements are provided for a clearer picture of kinetic effects. CORDEB tests have shown the importance of chemical interactions between molten steel and solid sub-oxidized (U-Zr- O) corium which lead to penetration of steel inside the solid oxide (crust or debris) and to the partial dissolution of the solid. As a consequence, the crust surrounding a molten pool cannot be considered as a barrier to mass transfer. CORDEB tests also made it possible to assess the oxidation kinetics of a molten pool: in the presence of surface crust, this is a rather slow process and it does not have a significant effect on the deterioration of accident scenario. The gaseous atmosphere above the pool plays an important role in several processes, in particular in the evaporation of molten steel.

Development of porous refractory ceramic plugs: Will the next generation be 3D printed?

Controlling non-metallic inclusion content during secondary metallurgy is a key feature in ensuring the quality of steel. In a typical process, these particles are captured by bubbles generated by a ceramic porous plug located at the bottom of the ladle, whose structure consists of open pores that allow gas injection into the molten bath. Nevertheless, during the non-bubbling period, liquid steel can penetrate through this porous structure, solidifying at the colder plug regions. In order to withdraw this infiltrated thickness, an oxygen lance heats the surface of the porous plug to resume its operation for the next process run. This cleaning procedure is pointed out as the leading wear mechanism for such a refractory. A classical approach to understand the infiltration of a liquid in a porous structure is based on Washburn's equation, which defines the starting condition for liquid penetration. By applying the same fundamentals to this problem, a criterion to avoid liquid steel infiltration into the plug is set. In this study, the influence of the pore diameter, the material composition, the gas counter-pressure and the ceramic structure tortuosity on steel penetration was analysed. Based on these results, feasible routes were proposed as countermeasures to refrain the molten metal infiltration of porous refractory ceramic purging plugs.

Friction anlysis of large diameter steel cylinder penetration process using 3D-DEM

Large open-ended cylinder piles have been widely used for engineering foundation of port. The penetration process of the large-diameter steel cylinder exhibit complex behaviors, which is difficult to be measured by test and reproduced in numerical models. This study presents a friction analysis of large diameter steel penetration process by using the discrete element method (DEM), which can simulate large deformation and nonlinearity well. Centrifugal model and full-scale model were developed to analyze the sliding friction of the cylinder during installation and the contact force chain of soil particles. The validity of the DEM model was examined by comparing with theoretical values and published studies. Parametric studies were carried out to study the effects of contact parameters on side friction. Simulation results showed that, unlike pile penetration, there is no obvious soil-plug effect during the penetration process of large-diameter steel cylinder. Besides, the inside friction is smaller than the outside friction for large-diameter steel cylinder. What’s more, the computational cost of full-scale model based on the upscale theory was less than the centrifugal model. There is a close relationship between the side friction and micro contact parameters, which provides a reference for the follow-up study of cylinder or pile penetration using DEM.

Risk evaluation of ballistic penetration by small caliber ammunition of live-fire shoot house facilities with comparison to numerical and experimental results

The development of advanced small caliber weapon systems has resulted in rounds with more material penetration capabilities. The increased capabilities may mean that existing live-fire facilities will no longer be adequate for the training and certification of military and law enforcement personnel. Constraints on training in many live-fire shoot house facilities are already in place, with some allowing only single round impact during training. With little understanding of the probability of perforation, or failure, of existing containment systems, this study evaluates risk by studying the single round impact of small caliber ammunition against live-fire shoot house containment systems constructed from AR500 steel panels with two-inch ballistic rubber covering. An analytical and numerical study was conducted using an existing model for steel penetration developed by Alekseevskii-Tate and the EPIC finite element code. A modified form of the advancing cavity model for the ballistic resistance of the target material was used to account for the relatively unconfined material resulting from the studied impacts. These results are then compared to experimental tests conducted by Goodman for rounds of various small calibers impacting live-fire facility containment systems. Projectile and target characteristics were then modeled as continuous random variables, and Monte Carlo simulations were conducted using the validated analytical model to estimate the probability of a single round impact perforating the live-fire facility containment system. An importance sampling scheme was used to reduce the variance of the solution and provide a more accurate estimate of the probability of failure. The Alekseevskii-Tate model was found to provide accurate estimates of the depth of penetration when compared to experimental and numerical results at ordnance velocities and an estimate of the probability of failure is on the order of 1x10-5. This study provides useful tools for the analysis of existing live-fire facilities against future and existing ammunition, and for the design of new facilities. When coupled with Monte Carlo simulation techniques, a risk-based approach to certify live-fire facilities for use with any variety of small arms ammunition can be applied.

Interfacial microstructure and mechanical properties of laser-welded 6061Al/AISI304 dissimilar lap joints via beam oscillation

Oscillating laser welding of 2-mm-thick 6061-T6 aluminum alloy and AISI304 steel in overlap configuration was performed under various oscillation amplitudes of 0, 3, and 5 mm. The experimental results indicated that the welding window of Al/steel dissimilar joints was improved with increasing oscillation amplitudes. The beam oscillation broadened weld width and interfacial bonding width while reducing weld depth. In the joint produced under 0-mm oscillation, a multi intermetallic compound (IMC) layer formed with a thickness of about 90 μm. In the joint produced under 3-mm oscillation, the IMC layer with the compositions of η-Fe2Al5+block-shaped θ-Fe4Al13) was obtained and its corresponding thickness reduced to 20 μm. When the oscillation amplitude further increased to 5 mm, only a η-Fe2Al5+little θ-Fe4Al13 layer with a thickness of 5 μm generated. Simulation results for the temperature history indicated that an oscillating laser beam would disperse laser energy, restraining the steel penetrating. Besides, dispersed heat energy depressed the melting of lower aluminum sheets and interfacial element diffusion. Thus, the formation of IMCs was suppressed. The limited IMCs and increased bonding width led to an improvement in the tensile–shear properties. The maximum fracture load of the joint under 5-mm oscillation was 185 N/mm, which was twice higher than that of joints welded without beam oscillation. Less Al atoms dissolved into the fusion zone under beam oscillation, resulting in lower microhardness and better toughness. Fracture locations changed from the fusion zone to the interface due to weakened steel penetration and improved toughness.

Selected Issues of Increasing the Fire Effectiveness of Combat Vehicles

Abstract The research paper reviews selected issues associated with the current state of the armoured (tanks) and infantry fighting vehicle technology, with particular emphasis on the operating effectiveness of elongated sub-calibre projectiles fired from tank guns, which enable full perforation of ca. 500 mm thick armour steel plates. Their efficiency is comparable with the impact of shaped heads with armour steel penetration capabilities, and amounts from 6 to 8 calibres – warhead diameters. Furthermore, the paper discusses a numerical analysis, which shows the velocities of elongated projectiles (of tungsten matrix sinters) required to achieve a determined armour steel penetration depth. In addition, it also presents the performance characteristics of two 100 mm calibre shaped warheads, with copper inserts and apex angles of 51º and 60º.

Study the Effect of Welding Position and Plate Thickness to the Mechanical and Microstructural Properties of the TIG Dissimilar Metal Welded between Carbon Steel ASTM A36 and Stainless Steel 304 Plates

Dissimilar metal welding was mostly done to optimize the application and engineering requirements with economic considerations. Weld microstructures greatly influenced the mechanical properties of welded joints. The investigations were carried out to evaluate the microstructural and mechanical properties of dissimilar weldment between carbon steel ASTM A36 and austenitic stainless steel 304 with a variation of welding position (1G, 2G, 3G) and weld thickness (6 mm to 12 mm) joints by TIG welding. A detailed analysis was conducted on the weld zone composition, the microstructural, and mechanical properties. The results show that the welding position and thickness of the weld joints influenced the microstructure both in HAZ and weld metal. Size, distribution, and orientation of microstructure were improved and more uniform with increasing of welded joint thickness. In HAZ carbon steel, GB ferrite was dominant, especially for the flat welding position (1G), while for the horizontal position (2G) and the vertical welding position (3G) showed other structures such as Widmanstaten ferrite, hard-structures like martensite and bainite. In the region near the fusion line and the weld metal, the chemical composition changed due to thermal convection, diffusion, and macro-segregation caused by penetration of liquid metal carbon steel into the weld pool. SEM/EDS results indicated diffusion of carbon from carbon steel A36 to stainless steel 304 and formed the hard-structure along the fusion line. The mechanical test results showed that the tensile test breaking point occurred in the parent metal of carbon steel A36. The bending test results showed very high stress on the face side of the welding joint, and there are no cracks from the bending test result. Vickers hardness testing showed that the hardness distribution increased from the carbon steel HAZ to the stainless steel HAZ, and the maximum hardness has achieved the value of 297 Hv at the fusion line of stainless steel 304.

Influence of SAP on the chloride penetration and corrosion behavior of steel bar in concrete

The steel corrosion induced by chloride penetration is a great threaten to concrete structures, in particular exposed to marine environments. Super absorbent polymer (SAP), as a water reservoir, is probably conducive to reinforced concrete suffered from steel corrosion in marine environments. Therefore, the influence of SAP on the chloride penetration and corrosion behavior of steel in concrete were investigated using concrete mixed with 0∼2 kg/m3 SAP. The results indicate that the permeability and chloride diffusion coefficient consistently rise up with increasing with SAP dosage. Furthermore, the higher SAP dosage results in an ascending free chloride content when subjected to tidal zone. However, when exposed to atmosphere zone, the effect of SAP can be neglected. Moreover, the corrosion current of the sample with SAP are larger than that without SAP, while more corrosion products can be observed in the sample with SAP. Since the stress and strain applied on concrete and internal steel bar of specimens with SAP are apparently smaller, the propagation of crack caused by steel corrosion is probably postponed. Thus, it can be roughly concluded that for concrete subjected to marine environment, adding SAP to concrete can delay the failure process of reinforced concrete to some extent and an optimized dosage of SAP is suggested to be 1 kg/m3.

Wettability between 304 stainless steel and refractory materials

In the current study, the wettability between 304 stainless steels and refractory materials was investigated using the sessile drop method in a reducing atmosphere at 1550 °C. The contact angle between the stainless steel and the original refractory was 133°, and was 126° between the stainless steel and the used refractory. The lower dissolved oxygen content in the stainless steel after the reaction with the original refractory was responsible for the higher contact angle. Adhesion work of original and used refractories per mole was 41 kJ/m and 53 kJ/mol, respectively, indicating that the physical bond energy was dominant at the interface between the stainless steel and the refractory. The penetration of the steel into the used refractory was more serious than that into the original refractory, which was mainly influenced by the angle between the liquid drop meniscus and refractory pores based on the force analysis. The liquid slag phase formed in the refractory at the high temperature entered refractory pores, decreased the meniscus angle and promoted the steel penetration.

Statistical variability and fragility assessment of ballistic perforation of steel plates for 7.62 mm AP ammunition

The paper describes field test results of 7.62 × 51 mm M61 AP (armour piercing) ammunition fired into mild steel targets at an outdoor range. The targets varied from 10 mm to 32 mm in thickness. The tests recorded penetration depth, probability of perforation (i.e., complete penetration), muzzle and impact velocities, bullet mass, and plate yield strength and hardness. The measured penetration depth exhibited a variability of approximately ±12%. The paper then compared ballistic test results with predictive models of steel penetration depth and thickness to prevent perforation. Statistical parameters were derived for muzzle and impact velocity, bullet mass, plate thickness, plate hardness, and model error. A Monte-Carlo probabilistic analysis was then developed to estimate the probability of plate perforation of 7.62 mm M61 AP ammunition for a range of impact velocities, and for mild steels, and High Hardness Armour (HHA) plates. This perforation fragility analysis considered the random variability of impact velocity, bullet mass, plate thickness, plate hardness, and model error. Such a probabilistic analysis allows for reliability-based design, where, for example, the plate thickness with 95% reliability (i.e. only 1 in 20 shots will penetrate the wall) can be estimated knowing the probabilistic distribution of perforation. Hence, it was found that the plate thickness to ensure a low 5% probability of perforation needs to be 11–15% thicker than required to have a 50/50 chance of perforation for mild steel plates. Plates would need to be 20–30% thicker if probability of perforation is reduced to zero.

Experiments on interactions of molten steel with suboxidized corium crust for in-vessel melt retention

In the framework of the European IVMR project, dedicated to the assessment of In-Vessel Retention (IVR) strategy for high power reactors, VITI-CORMET tests, performed in VITI facility (CEA-Cadarache/PLINIUS Severe Accident Platform), intend to study the interaction between a molten 304L stainless steel droplet and suboxidized solid corium crust, referred to as C-70 ((U0.54, Zr0.46)O1.74). In the present paper, original experimental results on molten steel penetration through a corium crust are presented. Identification of penetration mechanisms is performed by SEM/EDX analyses, and has shown that molten steel can penetrate through pre-existing cracks or by a dissolution process. The latter is found to be the dominant penetration mechanism and involves material transport from the crust to molten steel. Penetration kinetics is studied by measuring the average penetration length at different exposure times. It is found that the penetration by dissolution decelerates with time, while U and Zr contents tend to reach an equilibrium value within the metallic droplet.

Superior tensile fracture strength of hot isostatically pressed TiC–steel metallic composite fabricated by a novel infiltration

A metallic composite having TiC particle content as high as ~47 vol% in a cold work tool steel matrix was successfully fabricated by a novel infiltration process. The penetration of the liquid steel reached geometrically complex regions, such that no interfacial flaw was observed. The interface between the ferrite matrix and TiC was semicoherent with a faceted morphology consisting of low-index planes of each phase. Owing to these characteristics of the interface, neither interfacial decohesion nor cracking was observed after the tensile fracture. The initial failure occurred in the TiC particle by a {100} cleavage fracture. The cracks formed from each fractured TiC particle interlinked forming a major crack. The hot-isostatically pressed composite exhibited 16% higher strength (919 MPa) than the as-infiltrated composite (791 MPa). The fracture strength of the composite largely depended on the degrees of suppression of the TiC cracking and its propagation. The residual stresses pertaining to the TiC and steel matrix were measured by X-ray diffraction. They were not significant factors responsible for the increased fracture strength of the hot-isostatically pressed composite. The increased strength of the hot-isostatically pressed composite could be explained in terms of the mutually interactive influences of the load transfer mechanism, matrix toughening, reduced TiC contiguity, and M7C3 carbide bridging TiC particles.

STUDY ON A-TIG WELDING ENERGY EFFICIENCY OF STAINLESS STEELS USING INDIVIDUAL FLUX-OXIDES Part 1: EVALUATION OF THE A-TIG ARC ENERGY EFFICIENCY TO THE WELD DEPTH OF PENETRATION

This article presents the results of the study of activating oxide fluxes effects on the energy efficiency of the TIG welding arc (A-TIG) influence. This efficiency was estimated by the amount of energy spent by the arc (q) at the depth of penetration (P). It is revealed that the arc energy efficiency factor “Kepac” can be used as an indicator of the influence of arc energy on the efficiency of penetration of the welded metal, which is determined by the ratio of spent energy per unit of depth of penetration (q/P) at TIG and A-TIG welding. In accordance with the results of the research, it is observed an increase of the energy efficiency on the welding arc penetration capability of all individual oxides used as fluxes in A-TIG welding is observed. Among them, the greatest energy efficiency of the arc process on the penetration of CrNi18-10 steel is observed when oxides such as TiO2, SiO2, Cr2O3 and Co3O4 are used.