Researches concerning the ultasonic energy influence on the resistence to the abrasive wear of loaded welded parts

The researches presented in the paper refer to the effect of ultrasounds propagation in the liquid metal bath on the process of transferring the additive material through the electric arch and on the crystallization process, and all these effects are analyzed for loaded welded parts solicited at the abrasive wear. All these influences are conferred to these two basic phenomena due to the ultrasounds propagation in liquid environments, namely, ultra-acoustic cavitation and acceleration of the diffusion process. The results concerns the resistance to the wear obtained for the loaded parts through manual welding with electric arch and classically covered electrode and ultrasonically activated

The influence of the specific rehabilitation techniques „toegrindig” and „WIG remelting” in case of welded structure

The fillet welded structures, fatigue stressed, must have a concave shape in cross section and a smooth transition between weldseamand base material, without stress concentrators . In this issue for the welded structures with convex fillet welds, to improve the behavior in case of fatigue loads it will be necessary to apply rehabilitation techniques like toe grinding or WIG remelting. The paper wants to present the influence of that two rehabilitation technique and the behavior of the rehabilitated welded structures in case of static and dynamic loads

Research on environmental impact assessment of flame oxyacetylene welding processes

This paper presents the factors that may cause pollution of the work environment when working with the oxyacetylene flame welding process. Experiments were performed using an oven that allows the analysis of all gases resulted in the welding process, but also enables their monitoring using a video camera, and the resulting film was processed in that the frames for each second of experimentation were extracted. The materials used in the experiments were S235JR steel as the base material, and as filler materials, E70S. In order to assess the impact on the work environment of this welding process, the pollution coefficient CP was defined based on the equation of the material balance

Influence of use of ultrasound on the mechanical properties of plated pieces by welding in ultrasonic field

Plating by welding in an ultrasonic field represents a technological solution to increase resistance to corrosion and / or wear of pieces of the machinery industry. Research has been carried out for two types of parts, namely a piece of flange end type and bonnet type made of AISI 4130 steel, and as filler material for plating was used Inconel 625 Fe developed as electrode wire with a diameter of ø 1.2 / mm. The plating was done by depositing a single layer by welding in ultrasonic field, welding process in Ar 100/ % environment non-consumable tungsten electrode, WIG process, and when using ultrasonic activation it was used a longitudinal and a transverse wave with a frequency of 15 / kHz. For pieces plated by welding there have been made attempts of the hardness and tensile and bend shock

Influence of use of ultrasound on metallographic structure of plated pieces by welding in ultrasonic field

To optimize the plating process is necessary to know the behavior of surfaces plated during the exploitation and in particular susceptibility to cracking, the formation of cracks from the inside to outside or reverse, embrittlement in the heat affected zone. Research has been realized considering several samples plated by welding without ultrasonic activation and with ultrasonic activation, and these samples were made of AISI 4130 steel, and as filler material was used Inconel 625 Fe developed as electrode wire ø 1,2 / mm. The plating process was realized by a WIG welding process in Ar100 /% environment with non-consumable tungsten electrode, in two versions, respectively with and without the use of ultrasonic energy. Four pieces played by welding there were analyzed the metallographies structure in the base material, the deposited material and the material from the heat affected zone

Ultrasound effect on the mechanical properties of parts loaded by welding

The reconditioning problem by loading parts through welding is a special one because with this operation is desired in addition to a recovery of the initial size of the piece and also an increasement of resistance to fatigue and wear by erosion and/or corrosion. The paper presents research results on the mechanical properties of parts reconditioned by manual coated arc welding directly respectively by introducing ultrasounds in the welding bath. Application of ultrasounds in the welding process showed an increase in hardness, shock tensile and bending resistence for the parts material

Ultrasound influence on materials structure in parts reconditioned by welding with ultrasonic field

Research presented in the paper refers to the structural analysis of materials that are thermally influenced for loading by welding of pieces in the classical variant of manual coated electric arc welding and the version that in which the welding bath is activated by ultrasounds. The structural analysis made refer to: the size of the grains of the structure obtained under certain loading conditions through welding, grain size variation on the submission of a single layer in the ultrasonic field, the mode of solidification and fragmentation of grains when loaded in welding in a ultrasonic field, acceleration of the diffusion process for ultrasonic activation, the appearance of hard carbides between grains

Theoretical and experimental contributions regarding the impact on work environment of welding processes in MIG / MAG protective gas medium

This paper presents the main factors that cause environmental pollution in the case of the welding procedure in a protective gas environment. In the research the MIG and MAG welding processes were taken into account. The materials used in the experiments were 8TiCr170 stainless steel as the base material and as filler materials 4 types of welding wires were used, characterized by different chemical compositions. To assess the impact on the work environment of such welding processes the pollution coefficient Cp was defined based on the material balance equation as the ratio of the mass of all materials used in the welding process Mt and the effective mass of the welded performed Mu

Theoretical and experimental contributions regarding the impact on work environment of welding processes in MIG / MAG protective gas medium

This paper presents the main factors that cause environmental pollution in the case of the welding procedure in a protective gas environment. In the research the MIG and MAG welding processes were taken into account. The materials used in the experiments were 8TiCr170 stainless steel as the base material and as filler materials 4 types of welding wires were used, characterized by different chemical compositions. To assess the impact on the work environment of such welding processes the pollution coefficient Cp was defined based on the material balance equation as the ratio of the mass of all materials used in the welding process Mt and the effective mass of the welded performed Mu