Promising use of high-strength nitrogen steel for the ice belt of marine machinery operating in the extreme arctic conditions

This article shows the possibility of using high-strength nitrogen-containing corrosion-resistant steel grade 04Kh20N6G11M2AFB for the construction of critical elements and units of marine equipment operating at low temperatures, including the Arctic. The advantages of nitrogen-containing steel over clad steel AB2 + 08Kh18N10T always used in shipbuilding and welded steel of F500W category are considered. According to the assessment of testing of homogeneous nitrogen steel sheets, the level of its physical and mechanical properties exceeds the analogous parameters of traditional AB2 + 08Kh18N10T steels in a wide temperature range, up to –90°C.

On the Possibility of Developing Magnetostrictive Fe-Co/Ni Clad Plate with Both Vibration Energy Harvesting and Mass Sensing Elements

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) has spread rapidly around the world. In order to prevent the spread of infection, city blockades and immigration restrictions have been introduced in each country, but these measures have a severe serious impact on the economy. This paper examines the possibility of both harvesting vibration energy and detecting mass by using a magnetostrictive alloy. Few efforts have been made to develop new magnetostrictive biosensor materials. Therefore, we propose magnetostrictive Fe-Co/Ni clad steel vibration energy harvesters with mass detection, and we numerically and experimentally discuss the effect of the proof mass weight on the frequency shift and output voltage induced by bending vibration. The results reveal that the frequency and output voltage decrease significantly as the mass increases, indicating that the energy harvesting device is capable of mass detection. In the future, device miniaturization and the possibility of virus detection will be considered.

Welding of pipes in fixed position with internal anti-corrosion protection of joints

The article reviews the weldability of clad steel used for protection of inner surface of oil-and-gas pipelines from corrosion by different welding materials. It is indicated that during welding of the root pass by stainless electrodes in one pass the transition structures appear on the interface of two dissimelar metals. This process leads to the formaion of cracks. To reduce negative impact of the transition structures on the characteristics of welded joints it is recommended to weld the first two passes with strainless electrodes.

Method of investigation of local corrosion processes on samples from clad steel

The article describes a method developed to evaluate the mechanism of local corrosion processes on the surface of a clad layer of steel specimens, which makes it possible to identify the difference in electrode potentials in artificially created holes. As a result of the study it was found that in a corrosive medium containing Cl- and S2O32- ions, the diffusion of oxidants into a hole of smaller diameter is difficult, which causes a large potential difference between the wall of the hole and its bottom. This process contributes to the development of local electrochemical corrosion.