International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

CMT technology provides significant advantages, such as reduced deformation due to high temperatures, high welding speed and a significant reduction in spatter compared to the MIG/MAG method. The experimental work was focused on verifying the possibility of renovating the surfaces of molds for high-pressure aluminum casting using CMT technology. A mold wear analysis was performed and a method of restoring functional surfaces was proposed. Two types of additive materials were used – Thermanit 625 and Thermanit X. The quality of the layers was evaluated by SEM, EDX microanalysis and the coefficients of friction of the layers were determined by the Ball-ondisc method. The renovation layers were also subjected to an immersion test in Al alloy at 680 °C.

The paper focuses on the evaluation of the quality of fillet welds produced robotically by the method of impulse synergic welding MAG. This welding technology is used in the automotive industry in the production of rear seat backs for passenger cars. In the process of automated production, the speed of the process, accuracy, and quality of the made joints are important. Several factors affect the accuracy and quality of welded joints. The paper presents the results of research where the influence of filleting of fillet welds on their quality was confirmed. Visual and capillary methods were used to determine the quality of welds, metallographic analysis for evaluation depth of weld root penetration, strength properties of welds were evaluated by static tensile test. Statistical ANOVA methods were used to process the obtained values. Experimental work confirmed that the depth of welding of the weld root into the base material has the greatest influence on the final quality of fillet welds. It is this parameter that results in the elimination of the weld and thus the entire produ ct.

The paper presents the results of quality evaluation of weldments produced by a mutual combination of different steel grades. Weld joints were made using GMAW technology (method -135 ISO 4063). The type of welding parameters used for the quality of welded joints was monitored. The quality of welded joints was assessed using non-destructive tests. In non-destructive tests, the Visual test according to EN ISO 17637, the Penetration test with colour indication according to EN ISO 22476-12 was used to identify surface defects. The presence of internal errors was assessed by a radiation test according to EN ISO 17636-1. Within the destructive tests, the quality of the welds was assessed by a tensile test according to EN ISO 6892-1, by the test of brittleness of welds according to EN ISO 5173, the course of hardness according to EN ISO 6507-1 was determined on transverse cuts. The bending impact test according to EN ISO 9016 will determine the toughness of the weld metal and heat-affected areas. Metallographic analysis of welds according to EN ISO 17639 was performed on transverse metallographic sections using light microscopy. Based on the performed experiments, recommendations were set, or proposed changes in the welding procedures of the given steel grades.

The paper presents the results of research focused on the restoration of functional areas of products by the application of PTA technology. Hardfacing layers intended for the renovation of the surfaces of aluminum alloy injection molds were evaluated. The base material was medium alloy steel X38CrMoV5-1 (H11). Three types of powder additives were applied to form the functional layers: two types based on iron, designated HSS 23 and HSS 30, and one type based on nickel, designated DEW Nibasit 625 -P. The quality of the layers was evaluated using non-destructive and destructive tests. The surface integrity of the layers was assessed by visual and capillary tests. The microstructure of the materials and its hardness were evaluated. The tribological properties of the welds were determined by the pin-on-disc method.

The paper presents the results of the research of the evaluation of the overlay layers quality made by the fusible arc methods. By applying arc welding methods, it is possible to significantly extend the life of injection molds and thus significantly reduce production costs. The newly formed layers must meet a number of requirements so as not to degrade the advantages of high-pressure injection technology over conventional casting technologies. High pressure casting solves most of the problems of conventional casting technologies such as: porosity of the casting, high surface roughness, long casting time, inability to produce thin cross-sections and low dimensional accuracy. During exploitation, the mold surface is damaged, mostly by thermal cracking and combined adhesive-abrasive wear. Material used for high pressure die casting permanent mold is a medium alloyed hot tool steel Uddeholm Dievar. Layers were made using three types of filler materials on the Fronius TransTig 4000. To eliminate the effect of mixing, three layers were made. The quality of the deposits was assessed by non-destructive and destructive tests.

The paper presents results of quality evaluation of hardfacing layers applied to functional parts of dredger teeth. Layers were made by arc welding methods MMAW and FCAW. High-alloy types of filler materials were used in the experiment. Their chemical composition allows the production of overlay layers with a high content of carbide particles. These particles ensure high resistance to abrasive wear of the layers. Excavator teeth were made by casting high-grade manganese steels Grade B-3 A 128 / A128M-93. In the experiments, the presence of surface defects of the weld deposit was assessed by visual inspection. The resistance of the hard-facing layers to the effects of abrasive wear was assessed using a Di-1 experimental apparatus and evaluated on the basis of weight loss.