Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
This paper presents an overview of a research on six practical cases that were solved in a precise casting company where parts are cast by the mean of the low-wax casting method (investment casting) in order to decrease poor quality production. The steel cast parts production technology by the lost-wax method requires the detailed work procedures observation. On the base of statistical processing data of given types of casting products, it was possible to assess the significance of each particular checking events by using the statistical hypothesis testing. The attention was focused on wax and ceramic departments. The data in technological flow were compared before and after the implementation of the change and statistical confirmative influences were assessed. The target consisted in setting such control manners in order to get the right conditions for decreasing poor quality parts. It was evidenced that the cast part defect cause correct identification and interpretation is important.
EN
This paper presents an overview of a research on six practical cases that were solved in a precise casting company where parts are cast by the mean of the low-wax casting method (investment casting) in order to decrease poor quality production. The steel cast parts production technology by the lost-wax method requires the detailed work procedures observation. On the base of statistical processing data of given types of casting products, it was possible to assess the significance of each particular checking events by using the statistical hypothesis testing. The attention was focused on wax and ceramic departments. The data in technological flow were compared before and after the implementation of the change and statistical confirmative influences were assessed. The target consisted in setting such control manners in order to get the right conditions for decreasing poor quality parts. It was evidenced that the cast part defect cause correct identification and interpretation is important.
EN
The article deals with the influence of chemical composition of martensitic stainless steel for castings GXCrNi13-4 (the 1.4317 material) on mechanical properties and structure of as cast steel after heat treatment. Properties of these martensitic stainless steel are heavily influenced by chemical composition and structure of the material after heat treatment. Structure of these steels after quenching is formed with martensite and residual austenite. When tempering the steel the carbon content in martensite is reduced and gently deposited carbides occur. The way of heat treatment has a major impact on structure of martensitic steels with low carbon content and thus on strength, hardness and elongation to fracture of these steels. Chemical composition of the melt has been treated to the desired composition of the lower, middle and upper bounds of the nickel content in the steel within the limits allowed by the standard. Test blocks were gradually cast from the melt. The influence of the nickel equivalent value on structure and properties of the 1.4317 steel was determined from results of mechanical tests.
EN
This report addresses some chosen statistical methods that could be used to confirm and set up the required functions of technology in foundry companies where parts are cast by the low-wax casting method, whereas these chosen statistical methods are intended to reduce poor quality of produced parts. This research was made on a practical example. Utilization of hypothesis testing methods was examined in order to confirm technological parameters having some influence on the products quality. The data were compared before and after the implementation of changes aimed at reduction of poor quality produced parts in the wax department. The results confirmed that the implemented change had a statistically conclusive influence.
PL
Artykuł przybliża niektóre wybrane metody statystyczne, które można wykorzystać w celu sprawdzenia ustawień wymaganych funkcji w technologii odlewania metodą wosku traconego, do zmniejszenia wad produkcji. Badania przeprowadzono na konkretnym przykładzie. Zbadano wykorzystanie metod testowania hipotez w celu sprawdzenia parametrów technologicznych wpływających na jakość odlewów. Porównano dane przed i po wprowadzeniu zmian w celu ograniczenia wad produkcji w dziale woskowni. Wyniki potwierdziły, że wprowadzona zmiana miała statystycznie udokumentowany wpływ.
EN
The paper summarises experience with using synthetic slags on the CaO - Al2O3 oxide basis in the technological flow of the oxygen converter steelworks in TŘINECKÉ ŽELEZÁRNY, a.s. These slags are used as an alternative to slags containing fluorspar which unfavourably affects both the service life of ladle linings and the steelwork's working environment. The content gives the first knowledge of using the Refraflux type synthetic slag to desulphurize steel, and it also provides a basic statistical evaluation of the heat produced.
PL
W pracy podsumowano doświadczenia z użyciem żużli syntetycznych bazujących na tlenkach CaO - Al2O3 w technologii dmuchu tlenu w konwertorze stalowni TŘINECKÉ ŽELEZÁRNY, a.s. Żużle te są stosowane jako alternatywa dla żużli zawierających fluoryt, które niekorzystnie wpływają zarówno na żywotność wyłożenia kadzi i środowisko pracy stalowni. Artykuł przedstawia pierwsze doświadczenia z wykorzystaniem syntetycznych żużli typu Refraflux do odsiarczania stali, a także podstawowe dane statystyczne wytopu.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.