Corrosion Resistance, Evaluation Methods, and Surface Treatments of Stainless Steels

Stainless steels are widely recognized and find applications in many engineering industries and companies due to their excellent properties including high resistance to corrosion as a result of their minimum 10.5% chromium content, exceptional strength and durability, temperature resistance, high recyclability, and easy formability. In the present book chapter, the basic concepts of stainless steel including its applications, classifications, and corrosion properties will first be discussed. Thereafter, their corrosion behaviour will then be explained. The various methods by which the corrosion resistance behaviour can be significantly improved including surface treatments such as coatings/electrodepositions, alloying, mechanical treatment, and others will be discussed in detail.

technical level of small-town shoemaking in Gdańsk Pomerania in the 14th century

Based on the late medieval leather artefacts from Puck, Gniew, Lębork and Chojnice, an attempt was made to assess the level of shoemaking production at that time. Microscopic analyses of leather goods and production waste proved that in the field of tanning the activities related to the mechanical treatment of leather were carefully performed, although with insufficient professional knowledge concerning the process. The results of the identification of the animal origin of the leather confirmed the purposeful selection of raw material with different properties for individual footwear elements and the ability to properly cut it. The quality of the shoemaking products was highly rated in terms of technology and style. However, in the analysed collections a clearly perceptible difference in craftsmanship and assortment of products from Gniew and the other three towns was noticed.

Mechanical treatment of wastewater

Подбор оборудования для механической очистки сточных вод является важным этапом при реконструкции или новом строительстве очистных сооружений, который определяет их эффективность и надежность с точки зрения технологии и эксплуатации. Приведены примеры распространенных на данный момент технических решений по конструкции фильтрующего полотна решеток для механической очистки сточных вод. Дано сравнение эффективности данных решений. На основе исследования очистных сооружений в Германии представлено сравнение эффективности задержания отбросов в зависимости от применяемого ранга фильтрации: двумерной (перфорация) и одномерной (прозор). The selection of equipment for mechanical wastewater treatment is an important stage in the reconstruction or new construction of the treatment facilities that determines their efficiency and reliability in terms of the technology and operation. The examples of the currently widespread technical solutions for designing filtering cloth of the screens for mechanical wastewater treatment are given. The effectiveness of these solutions is compared. On the basis of studying wastewater treatment facilities in Germany, a comparison of the debris retention efficiency depending on the applied filtration grade, i. e., two-dimensional (perforation) and one-dimensional (bar spacing) is presented.

Experience in the application of the non-destructive method of acoustic emission in the production of titanium billets and products of transport engineering

The article discusses the issue of using the non-destructive method of acoustic emission at the stage of blank production. So, due to the violation of the heat treatment modes, various defects are formed in the starting material, which affects the operational properties of the finished products. To eliminate this problem, the stages of production of titanium blanks and products of transport engineering were studied, such as: heat and mechanical treatment, ultrasonic quality control, determination of the level of mechanical properties and control of the structure. In the course of the research, a method of acoustic emission control was developed and tested. The experiment on setting the locations of defects was carried out on ingots of VT22 titanium alloy during cooling. The reliability of the developed method is confirmed by the existing method of ultrasonic flaw detection. It has been established that this method can be effectively used to control workpieces and machined workpieces for the manufacture of particularly critical mirrors for searching for inhomogeneous inclusions and increasing the efficiency of the technological process by eliminating machining of VT1-0 titanium surfaces with inhomogeneous inclusions. In addition, this method can be used to search for defects commensurate with the grain size of the ingot, as well as significantly smaller sizes.

Electromagnetic characteristics of materials based on ultrafine hexaferrite powders

The electromagnetic characteristics of composite materials based on nanosized powders of W-type hexaferrites are considered in the article. It is shown that not only the composition, but also the mechanical treatment affects the electromagnetic parameters. This article presents the frequency dependence of the complex magnetic and dielectric permittivity of a system of W-type hexafferites. The studies were carried out on a universal wide-band measuring complex based on the Agilent PNA-X N4257A Vector Network Analyzer. The results are presented in the frequency range from 2 to 14 GHz.