Sławomir Kłos
Wykorzystanie planów Plackett a-Burmana i analizy opinii ekspertów w celu oceny istotności parametrów sterowalnych procesu cięcia plazmowego
W artykule dokonano oceny istotności parametrów sterowalnych procesu cięcia plazmowego za pomocą metody Placketta-Burmana i analizy opinii ekspertów. Badania procesu cięcia plazmowego przeprowadzono przy użyciu przecinarki plazmowej WPA- 6000 Compakt na stali niestopowej konstrukcyjnej gatunku S235JR EN 10025-2:2007 z ekwiwalentem węglowym wynoszącym 0.35 %. Analizowano wpływ grubości blachy, natężenia prądu, prędkości cięcia, ciśnienia gazów podczas cięcia, odstępu palnika od blachy podczas cięcia, czasu dziurkowania oraz wysokości startu. Badania ujawniły wpływ badanych parametrów sterowalnych procesu cięcia plazmowego na wybrane parametry wyjściowe, w szczególności na skok śladów cięcia, na szerokość szczeliny na wejściu i wyjściu oraz na wartość prostopadłości szczeliny do powierzchni bazowej. Największe wpływy zarejestrowano dla natężenia prądu, prędkości cięcia oraz ciśnienia gazu podczas cięcia. Otrzymane wyniki badań zostały potwierdzone wynikami analizy opinii ekspertów.
The use of Plackett-Burman plans and the analysis of expert opinions, in order to assess the significance of controllable parameters of the plasma cutt ing process
This article evaluates the significance of controllable parameters in the plasma cutting process, using the Plackett-Burman Method and the Analysis of Expert Opinions Method. The plasma cutting process was tested using a WPA-6000 Compakt plasma cutter, on non-alloy steel, of the S235JR EN 10025-2:2007 grade, with a carbon equivalent of 0.35%. The effect of the thickness of the sheet, the current flow rate, the cutting speed, the gas pressure during cutting, the height of the torch during cutting, the pierce delay time and the initial pierce height, were analysed. The research revealed the influence of the controllable parameters tested, in the plasma cutting process, on selected output parameters, surface cut drag lines, the width of the kerf at the inlet and outlet, and the value of the perpendicularity of the kerf on the surface of the base. The greatest influences were recorded for intensity of cutting current, cutting speed and gas pressure during cutting. The results obtained were confirmed by the results of the analysis of expert opinions.
Analysis and prediction of leak detection in the low-pressure heat treatment of metal equipment
The low-pressure heat treatment of metals enables the continuous improvement of the mechanical and plastic properties of products, such as hardness, abrasion resistance, etc. A significant problem related to the operation of vacuum furnaces for heat treatment is that they become unsealed during operation, resulting from the degradation of seals or the thermal expansion of the construction materials. Therefore, research was undertaken to develop a prediction model for detecting leaks in vacuum furnaces, the use of which will reduce the risk of degradation in the charge being processed. Unique experimental studies were carried out to detect leakages in a vacuum pit furnace, simulated using the ENV 116 reference slot. As a consequence, a prediction model for the detection of leaks in vacuum furnaces- which are used in the heat treatment of metals- was designed, using an artificial neural network. (93% for MLP 15-10-1) was developed. The model was implemented in a predictive maintenance system, in a real production company, as an element in the monitoring of the operation of vacuum furnaces.