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The changes in the material properties of water turbine blades are characterized an undesirable process, which could lead to the end of usable life or to the emergency conditions of this turbine. For this reason, it is important to determine of any material quality changes and continuously monitor them. Considering that, these essential parameters are showing the ability of material to resist the operational stress. It is necessary to choose rapid methods of the material testing which are without preparation of the samples (it is inadmissible to the functional blades) able to immediately monitor the state of the materials by nondestructive methods. Due to mechanical stress and operational wear, the losses and damage occur in the water turbine blades, as the result, it leads to the deformation changes. This article is focused on the methodology of determination mechanical properties of corrosion-resistant steel, which is used on a large scale for the production of hydraulic elements and especially blades of water turbines.

Al-Cu-Mg based alloys are often used in the automotive industry. There are characterized by high strength characteristics but poor corrosion resistance, which appears to be problematic in this sector. The manufactured blanks of these alloys may be protected by some of the barrier protection methods, including cladding. Semifinished products made of these methods can be protected against corrosion by a thin layer of aluminium oxidescalled clad Durals. The surface layer creates a stable and durable Al2O3 layer, which provides corrosion resistance, which leads to an extended service life of the piece. However, this type of protection is adversely affected by the effect of copper diffusion, which is dependent on the heat treatment mode of the alloy. Temperature and temperature hold are the main factors influencing the diffusion process. In the solution annealing of aluminium alloys, the temperature is in the range of (470-500) ° C, resulting in intense diffusion processes at the inter phases interfacial. The paper deals with the analysis of the influence of the heat treatment regime on the corrosion resistance of Al2024 alloy sheets (AlCu4Mg1 type alloy) provided with an Al1050 alloy clad coating on both sides in a corrosive salt mist environment in accordance with EN ISO 9227, which is supposed to have a positive effect on extending the service life of a car component.

An article deals with the assessment of the heat treatment of the material for a particular machine component. This material is 34CrNiMo6, made of two melts. This steel belongs to a group of materials with special properties for working at higher temperatures and for the production of demanding components, turbine wheels, cardan shafts, toothed wheels. The material was evaluated for microstructure quality before and after heat treatment. Based on metallographic microstructures, it is possible to review the heat treatment mode, which subsequently affects the mechanical properties of the components. For a particular design element, better cast material was recommended based on a comprehensive evaluation.

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