International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Galvanized steel pipes have long been widely used in drinking water supply systems due to the zinc coating that protects the steel from corrosion. However, during operation, especially when hot water is supplied, the zinc protective layer gradually breaks down, especially if there are galvanic pores in the pipeline or stray electric currents are generated in the pipeline. If the zinc coating is damaged, the steel base begins to corrode, rust forms, the pipe wall thickness decreases and the water quality deteriorate.
In addition to internal corrosion, a significant problem is external pipe corrosion caused by condensation forming on the surface of cold-water pipes. When the pipe surface temperature is below the dew point of the ambient air, moisture accumulates on it. Long-term wetting of the surface, especially if the zinc coating or protective paint layer is damaged, creates favorable conditions for the development of atmospheric corrosion. The corrosion process is further accelerated by poor indoor ventilation, high relative humidity or incorrectly calculated insulation layer thickness.
The article will examine two corrosion situations of steel pipes for drinking water supply using metallographic, water parameter studies, and stray current measurements.

Titanium rich alloys of Ti-Al-C and Ti-Al-B system was synthesised by Spark Plasma Sintering (SPS) and Field Activated Pressure Assisted Sintering (FAPAS) methods with altering sintering temperatures in the range of 950°C-1020°C with different current for the duration of 5 minutes. The initial powders of the composite 85%Ti and 15%Al was processed by High Velocity Energy Distribution (HVED) in a solution of kerosene at the specific energy of 25MJ/kg to reduce the size of the particles to nano-scale. This method of using different parameters of production technology have helped to analyse the most efficient, energy saving, and less waste generation technological process with improved mechanical properties. The metal-based samples were examined by optical and electron microscopy. Mechanical properties of composites were determined by measuring microhardness.
The aim of the investigation was to determine the dependence between parameters of production technology and properties of Ti-AlC composites.

Different types of oil are used widely in all over the world. It is used for lowering friction force at the contact zones, e. g., bearings, gears and other areas where at least one element is moving in relation to another one. Several types of oils find place in automotive industry: mineral, semi-synthetic and synthetic. Over the time oil characteristics were improved by enriching with different additives. Special additives can reduce friction forces, present better wash of abrasion products, extend oil life, etc.
This article deals with the research of degradation of oil lubrication quality in vehicle combustion engine over the exploitation period.
Quantity of contaminating particles in oil sample was determined by optical microscopy. Oil film strength test was performed with oil samples used after various exploitation periods.