This paper presents the results of a study of the influence of water and the commercial inhibitor VCI 379/611 on the corrosion behaviour of HTCS-130 hot work tool steel. Using the thermodynamic program Thermo-Calc, phase equilibria were determined according to the choice of calculation conditions and the known chemical composition of tool steels. From the obtained projections, it is possible to observe the secretion of individual phases at certain temperatures. To obtain insight into the corrosion resistance of steel, the following electrochemical methods were used: open circuit potential measurement; electrochemical impedance spectroscopy; and Tafel extrapolation. Metallographic tests were performed on a sample previously etched in nital to identify the microstructure of the steel. Using an optical microscope, the sample surface was analysed after each measurement. Images of the sample surface subjected to water without inhibitors indicate the occurrence of pitting corrosion. The presence of tungsten and molybdenum carbides was identified by scanning electron microscopy and energy dispersion spectroscopy. It was found that the corrosion process is more pronounced in the area of the metal base while in the areas of excreted carbides, weaker corrosion activity was observed.

The corrosion behavior of the EN AW-5083 alloy was investigated due to its widespread use in marine and transportation applications. The study examined the influence of microstructure development on corrosion behavior in both as-cast and homogenized conditions. Thermodynamic calculations, differential scanning calorimetry, and metallographic characterization were used to analyze solidification and microstructure development, while electrochemical testing was applied to evaluate corrosion resistance in a solution simulating severe outdoor exposure conditions, primarily marine, industrial, and transportation environments. The results show that the as-cast microstructure contains a heterogeneous distribution of anodic and cathodic intermetallic phases, which promotes localized corrosion. Homogenization at 520 °C led to the dissolution of the Al₈Mg₅ (β) phase, resulting in reduced sensitization effects and slightly improved corrosion resistance. However, high corrosion rates were observed in both metallurgical conditions, indicating limited resistance under the applied testing conditions. The study confirms that microstructural modification through homogenization influences corrosion mechanisms in EN AW-5083.

This paper studied the corrosion resistance of W600 tool steel in artificial rainwater and 3.5 % NaCl solution. The equilibrium phase diagram was determined from the material’s chemical composition, with calculations and thermodynamic simulations carried out using Thermo-Calc software, enabling accurate prediction of stable phases as a function of temperature and composition. According to the obtained projections, the solidification and precipitation of individual phases at characteristic temperatures was read. Following the completion of the electrochemical measurements, insight into the corrosion behavior of the tested sample was provided. Electrochemical tests showed a decrease in charge transfer resistance and an increased corrosion rate in the 3.5 % NaCl solution, indicating inadequate resistance in a chloride-containing solution, attributed to the formation of a thin oxide layer caused by the attack of chloride ions from the solution. Metallographic analysis confirmed the occurrence of slowly progressing pitting corrosion in chloride solution, while no significant changes were observed after testing in artificial rainwater. The lower rate of pitting corrosion was attributed to the martensitic microstructure with fine needle-like morphology with uniformly distributed carbides in the W600 tool steel. Such investigations are essential for understanding material behavior in aggressive environments and for reliably predicting its durability in real applications.

Fizikalne štetnosti obuhvaćaju buku, vibracije, svjetlost, zračenje i mikroklimatske uvjete prostora, koji predstavljaju potencijalni rizik za zdravlje i sigurnost radnika, ali i za okoliš. U današnje vrijeme polažu se veliki napori kako bi se smanjio rizik od fizikalnih štetnosti i njihovih posljedica, međutim postoje djelatnosti u kojima je nemoguće ukloniti sve rizike. Ljevaonice su, u pravilu, zatvoreni prostori u kojima dolazi do isparavanja, dima, prašine, buke, povišene temperature, radnici rade u prisilnom položaju tijela, manipuliraju velikim i teškim predmetima, rastaljenim metalom, stoga posljedično dolazi do velikog naprezanja organizma. Nažalost, radna mjesta u ljevaonicama zbog prirode samog procesa imaju nepovoljne uvjete rada i svrstavaju se u poslove s posebnim uvjetima rada. Zaposlenici raspoređeni na radna mjesta s posebnim uvjetima rada u potencijalnom su riziku od razvoja profesionalne bolesti bez obzira na korištenje osobne zaštitne opreme. U ovom radu navedene su i pobliže objašnjene fizikalne štetnosti koje nastaju tijekom radnih procesa u ljevaonicama uz osvrt i na druge opasnosti, štetnosti i napore s kojima se susreću zaposlenici tijekom metaloprerađivačkog procesa.