Elements machined by laser and abrasive water jet cutting sometimes require the use of a finishing treatment. One of the finishing methods for machined elements is vibratory shot peening (VSP). This paper presents the influence of VSP technological conditions on the surface topography and surface roughness (parameters Ra and Rsk) of aluminium alloy AW-7075 samples. Experiments were carried out according to the following plan: first, vibratory shot peening (VSP) was conducted using balls with a diameter d = 3 mm, 6 mm and 9 mm. Then, the surfaces of the samples after VSP (treated with 6 mm diameter balls) were subjected to re-vibratory shot peening (RVSP). As a result of vibratory shot peening, the Ra parameter of the specimens after laser cutting decreased by 71% to 91%, while for the AWJ-treated elements it decreased by 56% to 85%. The additional operation decreased the Ra parameter in the entry zone by 4% to 6% for the samples after laser cutting and by 5% to 7% for the samples after AWJ, when compared to the Ra value after single vibratory shot peening conducted using balls with d=6 mm. After VSP and RVSP, the surface topography of the samples changed. Vibratory shot peening led to the creation of "striations" on the shot-peened surface that could not be completely removed. The re-vibratory shot peening operation (for specific conditions) had a positive effect on the geometric structure of the surface of the elements after cutting. Both VSP and RVSP caused reduction in the analysed 3D surface roughness parameters.
Nowadays acoustic emission (AE) method is used in many fields of science, including in the diagnosis and monitoring of machining processes such as turning, grinding, milling, etc. Monitoring of turning process allows ensuring stable conditions of treatment. Stable conditions of turning process have a great impact on the quality of the surface. This is especially important during finishing treatment. The research was carried out on a universal ZMM-SLIVEN CU500MRD lathe centre-using tool with removable insert SANDVIK Coromant WNMG 080408 – WMX Wiper. Lathing process was performed on the shaft of 74 mm in diameter made of S235 steel. The research was carried out at constant cutting speed v = 230 m/min. Changed parameters were feed f = 0.1; 0.2; 0.4 mm/rev and cutting depth ap = 0.5; 0.75; 1 mm. In the research was used a set of acoustic emission Vallen System. The kit includes: 4 channel signal recorder AMSY 6, two measurement modules ASIP-2/S, preamplifier with a frequency range 20 kHz – 1 MHz and the strengthening of 34dB and AE signal measurement sensor type VS 150M, with a frequency range 100 – 450 kHz. During the study, the acoustic emission (AE) generated during the lathing process were recorded parameters e.g. amplitude, number of events – hits, the effective value of the signal (RMS). The test results indicate, that the higher instability of the process was during turning with parameters: ap = 0.75 mm and f = 0.1 mm/rev. The study can be the basis for the use of acoustic emission method for monitoring lathing process to ensure stable conditions of that process and the same to obtain a high quality surface.
Przedstawiono wyniki badań odporności korozyjnej blach cynkowych. Określono wpływ dodatków stopowych do cynku na odporność korozyjną wytworzonych blach oraz skuteczność zabezpieczania stosowanej obróbki wykańczającej blach. Przeprowadzono laboratoryjne przyspieszone badania korozyjne w dwóch standardowych ośrodkach korozyjnych: w obojętnej mgle solnej oraz w wilgotnej atmosferze zawierającej SO2. Stwierdzono, że stosowane w chwili obecnej dodatki stopowe tytanu i miedzi do cynku głównie w celu poprawy podatności blach do przeróbki plastycznej, wpływają również korzystnie na odporność korozyjną. Korzystnie na odporność korozyjną w początkowym okresie eksploatacji, a także na podniesienie walorów wizualnych, wpływa zabieg dodatkowego zabezpieczenia powierzchni cynku powłoką polimerową lub podwójną powłoką fosforanową i polimerową.
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Results of the investigation into corrosion resistance of zinc sheets are presented. An effect of the alloying components added to zinc on the corrosion resistance of the sheets fabricated and effectiveness of the applied protective final treatment have been determined. Accelerated laboratory-scale corrosion tests were performed in two standard corrosive environments: neutral salt spray and in a wet SO2-containing atmosphere. It was found that titanium and copper, which are added at present to zinc in order to improve workability of the sheets, exhibit also a beneficial effect on the corrosion resistance. Moreover, additional protecting of the zinc surface with a polymer coating or with a combined phosphate/polymer coating increases the corrosion resistance in the first exploitation period and improves appearance of the sheets.
Artykuł dotyczy obróbki wykończeniowej elementów rurowych wykonanych ze stali nierdzewnej, stosowanych w pojazdach samochodowych. W związku z licznymi zaletami wynikającymi z zastosowania metody gładkościowego nagniatania, proponuje się jej zastosowanie zamiast wykończeniowej obróbki szlifowaniem. Porównano wyniki pomiaru chropowatości powierzchni rur po nagniataniu gładkościowym z wynikami pomiaru chropowatości po szlifowaniu. Do badań wykorzystano rury ze stali nierdzewnej 1.4301. Proces nagniatania przeprowadzono przy pomocy głowicy do nagniatania bezkłowego i przelotowego, natomiast szlifowanie przy pomocy taśm ściernych. Przedstawiono wybrane wyniki badań doświadczalnych.
EN
Article applies finishing operation on elements made of stainless steel, used in vehicles. In connection with many advantages resulting from application of the smooth burnishing, it proposed to used it instead of finishing treatment grinding. The results of surface roughness on pipes after smooth burnishing with the results after grinding were compared. Stainless steel of pipes is 1.4301. The process was done using a head of through and centreless burnishing while grinding using a abrasive belts. The results of experimental research were presented in this paper.