Abstract:The paper presents the results of resistance spot welding of hot-dip galvanized microalloyed steel sheets used in car body production. The spot welds were made with various welding currents and welding time values, but with a constant pressing force of welding electrodes. The welding current and welding time are the dominant characteristics in spot welding that affect the quality of spot welds, as well as their dimensions and load-bearing capacity. The load-bearing capacity of welded joints was evaluated by tensile test according to STN 05 1122 standard and dimensions and inner defects were evaluated by metallographic analysis by light optical microscope. The welding parameters of investigated microalloyed steel sheets were optimized for resistance spot welding on the pneumatic welding machine BPK 20.

The paper presents the application of weld layers used in renovations of functional surfaces of components that are exposed to several tribodegradation factors in operation of metallurgical and engineering industries. Surfaces of selected components are renovated using arc welding processes, namely: (MMAW) Manual Metal Arc Welding, (SAW) Submerged Arc Welding methods, (GMAW) Gas metal arc welding and (FCAW) Flux cored wire metal arc welding without gas shield. Claddings were made always three-layered directly on the surfaces of renovated components using dedicated cladding machines in operations and laboratory conditions respectively. Their quality was assessed using non-destructive tests, namely (VT) visual testing by STN EN ISO 17637 and (UT) Ultrasonic testing STN EN ISO 11666. Within the destructive tests the quality of claddings was evaluated using the metallographic analysis conducted on a light microscope Olympus BX and electron microscope Jeol where the impact of mixing the weld metal as well as heat treatment after cladding on the final structure of claddings was observed. Using the Shimadzu HMV 2 device the microhardness of cladding layers was evaluated on metallographic samples by STN EN ISO 9015-2. In laboratory conditions the resistance of cladding layers to abrasive wear was verified on the device Di-1. Experimental testing of the claddings confirmed that the selected additives and cladding parameters witting individual technology were chosen correctly as in cladding layers no presence of internal defects was observed.

The paper deals with the tribological properties of investigated types of hard-faced materials at erosive wear process. Influence of inclination angle of elements on friction resistance and microhardness changes of hard-faced layer were investigated too. From quantitative aspect were hard-faced layers evaluated on the base of weight loses. From achieved results follow that inclination angle is one from determining factors on to material’s wear measure.

This article examined the possibility of using CuSn6P claddings in sliding bearing renovation of movable pontoon bridge props. The bronze layer was welded on cylinders of the high-strength steel S355J0WP EN 10155-93, in an inert atmosphere using an automated welding method (gas tungsten arc welding). Pulsed arc welding was used to minimize the effects of heat on the cladding area, while also accounting for the differences in the physical properties of the joined metals. The sliding bearing was created in two layers. The quality of the cladding layer was evaluated by nondestructive and/or destructive tests. The quality of the surface was assessed by visual inspection (visual testing) in accordance with the EN ISO 17637 standard. The quality of the claddings was evaluated by metallographic analysis, performed using light microscopy. The microhardness values of a few weld areas were determined by Vickers tests, performed according to the EN ISO 9015–2 standard. The analyses confirmed that the welding parameters and filler material used resulted in high-quality weld joints with no internal (subsurface) or metallurgical defects.

The article deals with the comparison and evaluation of milling strategies, which are available in CAM systems and are used for the production of components with freeform surfaces. For the purpose of the experiment a test sample with a repeating shape feature was designed. First half of the test sample shape features were machined using 3-Axis milling strategies while second half was performed with strategies available on 5-Axis CNC machining centre. Simulated machining times as well as virtually machined surfaces using color maps with deviation values were evaluated by employed CAM software. Obtained data was used to evaluate the performance of 3-Axis and 5-Axis milling centre both individually and mutually. These results will be used to compare software data with data obtained from real sample production. The main goal is to verify the reliability of the results provided by CAM systems in the production of parts with freeform feature surfaces.