The electrochemical corrosion properties of 26Mn-3Si-3Al and 27Mn-4Si-2Al austenitic steels in two different states were studied in 0.1 M H 2 SO 4 and 3.5% NaCl using potentiodynamic polarization tests. The effect of cold deformation on the microstructure and corrosion behavior of steels was analyzed. In acid solution, both steels exhibited lower corrosion resistance than in chloride solution independently on the steel state (hot-rolled, cold-worked). Cold deformation decreases the corrosion resistance, though this effect is smaller than the effect of chemical composition related to the combined Al + Si addition. All steels showed the evidence of pitting corrosion. The intensive dissolution of Fe and Mn takes place in the acid medium.

The main aim of the article was to present the investigation results of created megnetorheological fluids using carbonyl iron (CI) particles and analyse their behaviour in terms of the internal structure formation by a control of external magnetic field. Results of the experimental studies of a prototype magnetorheological rotary shock-absorber at various magnitudes of control current was presented in this paper.

This article presents the results of an examination of the properties of thermal flame sprayed coatings produced by material in the form of four powders (two polymers: PA11 and PA12 CastoPlast, and two high purity: tin and aluminum) on the substrate of the unalloyed structural steel of S235JR grade. Investigations of coating properties are based on metallography tests (SEM and CLSM), measurement of microhardness (acc. to PN-EN ISO 6507-1:2007), anticorrosive (acc. to PN-EN ISO 9227:2017-06) and bend testing. Results demonstrate properties of flame sprayed coatings that are especially promising in the industrial applications where corrosion-resistant coating properties are required. Consequently, performed experiments show that the highest corrosion resistance is demonstrated by steel samples with a polyamide anti-corrosion system. Accelerated corrosion tests showed the lowest corrosion resistance of the tin coating system, however, they do not fully correspond to the corrosion processes in operating conditions.

The paper presents the influence of heat treatment on the structure and corrosion resistance of X5CrNi18-10 steel. To determine the structure which has been obtained after heat treatment the methods of light and scanning electron microscopy with EDS microanalysis were used. The electrochemical corrosion properties of the investigated steel were studied in 3.5% NaCl solution using potentiodynamic polarization tests. Basing on the registered curves, the corrosion current, polarization resistance and corrosion potential were determined. The corrosion tests were followed by fractographic researches.

The article presents the results of the research on the influence of heat treatment conditions on corrosion resistance of newly developed HSLA-type (High Strength Low Alloy) steel in selected corrosive environments. Laboratory tests were carried out with using a salt spray chamber, enabling the continuous spraying of brine mist (5% NaCl) during 96 h under high humidity conditions. Additionally, as part of corrosion experiments, tests were carried out using the gravimetric method, in which the intensity of corrosive processes was measured by the linear corrosion rate. The research conducted revealed that the best corrosion resistance was noted for steel with a high-temperature tempered martensite microstructure. Investigated 0.28C–1.4Mn–0.3Si–0.26Cr steel with Nb, Ti, and V microadditions can be used in offshore drilling constructions and production platforms exposed to salts present in sea water, chlorides, sulfates, carbonates, and bromides, among others.

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This study discusses the effect of laser beam welding parameters on the structure, mechanical properties and corrosion resistance of 1.2 mm thick galvanized sheets made of low-carbon steel DC04 provided with a ZE36/36 GardoprotectOC2BU organic coating. The test laser beam butt welded joints were made without the filler metal, using a variable welding rate, where linear welding energy was restricted within the range of 30 J/mm to 90 J/mm. The joints were subjected to non-destructive tests, destructive tests and corrosion resistance tests. The tests revealed the possibility of making joints meeting the criteria specified in the ISO 15614-11 standard. Regardless of the value of linear welding energy applied in the process, all the joints were characterised by high mechanical and plastic properties. It was noticed that an increase in linear welding energy from 30 J/mm to 90 J/mm was accompanied by the widening of the weld and that of the heat-affected zone (HAZ). In addition, an increase in linear welding energy was accompanied by a decrease in the maximum weld hardness to approximately 250 HV0.2. In the HAZ, hardness was restricted within the range of 190 HV0.2 to 230 HV0.2 and decreased along with increasing linear welding energy. In the static tensile test, regardless of the value of linear welding energy, the test specimen ruptured in the base material. In the bend test, regardless of the value of linear welding energy, a bend angle of 180° was obtained without partial tear or scratches; unit elongation was restricted within the range of 29% to 42%. The electrochemical tests and experiments performed in the salt spray chamber revealed the very high effectiveness of the corrosion protections against aggressive chloride ions.

The paper presents the evaluation of the brazing capabilities of the multi-beam Trifocal laser joint system made of galvanized steel DX51D with a thickness of 3 mm, covered with a protective coating of Magnelis type. The brazed joints obtained have been subjected to metallographic, strength and corrosion resistance tests in the Ascott CCIP450 salt cell. The tests have shown that there is a certain range of brazing process parameters that allow to make the correct overlap joints of high quality with small welding distortions and a narrow heat affected zone. The obtained joints are characterized by a slightly worse corrosion resistance than the basic material, and zinc evaporation by means of additional low-power laser beams improves the solder's flow.