This reprint aims to promote and disseminate applied research in the field of corrosion of steel structures and technological equipment. Within the text, the focus is firmly placed on the detailed ...study of corrosion processes affected by specific environments, as well as on the effects of corrosion damage on the reliability and service life of structural components and technological equipment. Special attention is paid to the study of the impact of corrosion processes on pipelines.
Beam-to-column joints equipped with friction dampers are promising solutions to improve the performance of steel moment resisting frames due to the possibility to guarantee large dissipation capacity ...limiting the structural damage under severe seismic conditions. In this paper, the experimental tests and the numerical simulations of two types of joints are shown and discussed with the aim of developing pre-qualified configurations. The friction dampers are designed to be easily removable from both the lower beam flange and the column face by means of bolted connections. The devices are composed of a stack of steel plates conceived to assure symmetrical friction. The friction surface is set in vertical direction in first case and in horizontal direction in the second type. The experimental tests confirmed the effectiveness of both examined joints and the finite element analyses allowed characterizing their local response, thus providing additional insights to improve the design requirements.
•The behavior of steel beam-to-column joints equipped with friction dampers is investigated.•Dampers with both horizontal and vertical friction surface are investigated.•Experimental tests on joints equipped with friction dampers show satisfactory response with negligible damage.•The tested joints show non-symmetric response under hogging and sagging moment.•Finite element simulations show that the vertical friction damper exhibit plastic deformations lower than the horizontal friction damper.
Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe-Al-Mn-C alloys were patented in 1950s for replacement of nickel or chromium in ...corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest.
Slurry aluminide coatings were elaborated on IN-800HT and HR3C austenitic stainless steels (ASS) and on P92 ferritic-martensitic steels. The thermal treatments conducted in Ar enabled the melting of ...Al and the high temperature synthesis with the substrate elements to result in an aluminium diffusion coating. Whether for the ferritic-martensitic or the austenitic stainless steels, the coatings were formed by the simultaneous Al inward diffusion into the steel matrix and the outward diffusion of Fe (and Ni for the ASS) on both steel substrates. As a result, the coatings exhibited a B2-(Fe,Ni)Al phase for the ASS and B2-FeAl phase for the P92 substrate. A reduction of the grain size after annealing was noticed for the ASS but their microstructures remained mostly austenitic. However, a significant increase of the grain size occurred in the P92 steel with a transformation from the initial tempered martensitic structure to an austenitic structure. The microhardness of the ASS did not change significantly whereas for P92, a large increase occurred.
•Aluminide coatings successfully elaborated on austenitic steels (HR3C, IN-800HT) and on ferritic-martensitic steel (P92).•Diffusion layers were mostly composed by the B2-(Fe,Ni)Al and B2-FeAl for the austenitic and the ferritic steels.•The Al inward and the Fe (and Ni, for the ASS) outward diffusion allowed the formation of a homogeneous diffusion layer.•No significant evolution of the microstructure, grain size and microhardness of the ASS substrates (HR3C and IN-800HT).•The thermal treatment carried out on the P92 substrate had a non-negligible impact on the microstructure of this alloy.
In order to explore the corrosion resistance of duplex stainless steel under seawater corrosion and the compressive stiffness of its reinforced concrete columns, this study first performed seawater ...corrosion resistance tests on HRB400 ordinary steel rebar and S32205 duplex stainless steel rebar. The effect of the corrosion product film on the corrosion behavior was investigated through polarization curve tests and electrochemical impedance spectroscopy tests. The results showed that the corrosion rate of S32205 duplex stainless steel in a seawater environment was approximately 1/15 that of the HRB400 ordinary steel rebar. The anodic polarization curve of duplex stainless steel rebars exhibited a greater slope than that of carbon steel rebars. In the simulated seawater environment, the corrosion rate of these two kinds of steel bars showed different trends. The corrosion rate of ordinary steel bar HRB400 first decreased and then increased, while that of duplex stainless steel S2205 increased steadily. Furthermore, 18 short concrete columns reinforced with ordinary and duplex stainless steel rebars were subjected to the axial compression test and stiffness analysis; the stiffness of the short columns was calculated from the test data. The theoretical values agreed with the test values, with a stiffness calculation error of less than 5%.
The effects of the abrasive particle size and the pH-value of the aqueous solution on the abrasive wear resistance of H–13 steel and Hadfield steel were investigated. Abrasive wear tests, using a wet ...rubber wheel abrasion tester, were carried out applying abrasive sizes in the range of 0.15–2.40mm. The pH-values of the aqueous solution ranged from 5.5 to 12.8. The microstructure of each material was characterized with optical microscopy. The wear surfaces and the wear particles (debris) were analyzed by scanning electron microscopy (SEM). The macro- and microhardness were measured before and after the wear tests using a Vickers hardness tester. The surface topography of the wear scars was examined by a non-contact 3D profiler in order to measure the depth of the abrasive penetrations.
The results demonstrated that Hadfield steel is more wear resistant than H-13 steel for all pH-values and all abrasive particle sizes used in the tests. Moreover, the micro-hardness of the wear scar surface of the Hadfield steel increased significantly with the size of the abrasive grain, while this increase was lower for the H-13 steel. The greater work-hardening of the austenitic Hadfield steels was considered to be responsible for this higher wear resistance in comparison with the martensitic H-13 steel. For both materials the loss of mass increased linearly up to a critical abrasive particle size (CPS); this CPS, the mass loss continued to increase but with a lower gradient. An explicit effect of the steel matrix on the mass loss behavior as a function of the abrasive grain size was not observed. The less acidic aqueous solution resulted in lower mass losses for both materials and for all abrasive grain sizes. This effect was greater for the two smaller abrasive grain sizes. For higher pH-values, lower depths of penetration of the abrasive particles were observed. The analysis of the wear particles in all test conditions displayed continuous and discontinuous chips for the H-13 steel but only discontinuous chips for the Hadfield steel,. For both materials two abrasive wear micromechanisms were determined: microcutting and microploughing. Finally, the results presented in this work suggest that the wear performance analysis of Hadfield steel, to be used in an abrasive environment, should consider the effects of the pH value of the aqueous solution and the abrasive particle size.
•The effect abrasive size on wear resistance of Hadfield and H13 steels was analyzed.•A new Critical Particle Size value for wear in wet abrasion conditions was determined.•Both hardness and depth of the work-hardened layer are dependent on the abrasive size.•Decreases in the pH value of the aqueous solution resulted in higher mass loss.•The abrasion-corrosion synergism effect was determined for different abrasive sizes.
The production of steel in the world is dominated by two types of technologies: BF + BOF (the blast furnace and basic oxygen furnace, also known as integrated steel plants) and EAF (the electric arc ...furnace). The BF + BOF process uses a lot of natural resources (iron ore is a feedstock for steel production) and fossil fuels. As a result, these steel mills have a significantly negative impact on the environment. In turn, EAF technology is characterised by very low direct emissions and very high indirect emissions. The raw material for steel production is steel scrap, the processing of which is highly energy-consuming. This paper analyses the energy intensity of steel production in Poland as a function of investments made in the steel industry in the years 2000–2019. Statistical data on steel production in the EAF process in Poland (which represents an approximately 50% share of the steel produced, as the rest is produced utilising the BF + BOF process) was used. Slight fluctuations are caused by the periodic switching of technology for economic or technical reasons. The hypothesis stating that there is a relationship between the volume of steel production utilising the EAF process and the energy consumption of the process, which is influenced by investments, was formulated. Econometric modelling was used as the research method and three models were constructed: (1) a two-factor power model; (2) a linear two-factor model; and (3) a linear one-factor model. Our findings show that the correlation is negative, that is, along with the increase in technological investments in electric steel plants in Poland, a decrease in the energy consumption of steel produced in electric furnaces was noted during the analysed period.
•Requirement of intermediate transverse stiffeners in HSS plate girders was investigated.•AASHTO design equations can not be directly used for transverse stiffeners in HSS plate girders.•Additional ...out-of-plane deflection leads to an adverse effect on shear resistance.
The postbuckling capacity of HSS plate girders is larger than that of mild steel plate girders because of the differences in material properties. Hence, to fully develop the postbuckling capacity, the intermediate transverse stiffener requirement of HSS plate girders could be different from that of mild steel plate girders. The plate girders concerned in this study are without a longitudinal stiffener. To investigate the aforementioned issue, the minimum moment of inertia requirements of intermediate transverse stiffeners in HSS and mild steel plate girders are studied through the finite element analysis (FEA). After the comparison between the FEA results and the results from the design equations in AASHTO LRFD, it states that the design equations in AASHTO LRFD could not be directly used in the design of intermediate transverse stiffeners in HSS plate girders. Hence, based on the FEA results, a new equation is proposed to predict the minimum moment of inertia requirement of intermediate transverse stiffeners in HSS plate girders. Furthermore, because of the difference in the resistant capacity between HSS and mild steel plate girders, the maximum additional out-of-plane deflection of the intermediate transverse stiffener in HSS plate girders corresponding to the ultimate shear resistance is significantly larger than that of the intermediate transverse stiffener in mild steel plate girders. Hence, there is a noteworthy adverse effect caused by the additional out-of-plane deflection of the intermediate transverse stiffener on the shear resistance of HSS plate girders with the maximum limit value set.
•Axial performance of ultra-high strength CFST columns is presented.•Measures to improve ductility are provided.•Confinement effect should be ignored for calculating axial resistance.•Modified ...Eurocode 4 method is applicable to ultra-high strength CFST columns.
The use of high strength concrete and steel have significant advantages for composite members subject to significant compression as in the cases of high-rise buildings. Current design codes place limits on the strengths of steel and concrete due to limited test data and experience on the behaviour of composite members with the high strength materials. To extend their applications, a comprehensive experimental program has been carried out to investigate the behaviour of concrete filled steel tubes (CFSTs) with high- and ultra-high- strength materials at ambient temperature. This article presented some new findings on the axial performance of 56 short CFSTs. High tensile steel with yield strength up to 780MPa and ultra-high strength concrete with compressive cylinder strength up to 190MPa were used to prepare the CFST test specimens. The key issue is to clarify if the plastic cross-sectional resistance could be used at ultimate limit state as for CFSTs with the normal strength materials. To address this, experimental and analytical methods were adopted where the test results were compared with the predictions by various design codes world widely, and design recommendations were therefore proposed so that the prediction methods could be safely extended to the short CFSTs with the high- and ultra-high- strength materials.
•Cold-formed stainless steel RHS undergoing combined bending and web crippling was studied.•34 tests were conducted on specimens of lean-duplex and ferritic stainless steel grades.•Parametric studies ...of 312 specimens were performed.•Current combined bending and web crippling design provisions are shown to be conservative.•Improved design rules are suggested in this study.
The behaviour and resistances of cold-formed stainless steel rectangular hollow section (RHS) members undergoing combined bending and web crippling were studied based upon experimental and numerical investigations. A test program consists of 4 pure bending tests, 7 pure web crippling tests and 23 web crippling-bending interaction tests was conducted. The RHS specimens were cold-rolled from lean-duplex and ferritic stainless steel sheets. Numerical models were built and validated against the test results. Upon validation, parametric studies comprised of 312 finite element analyses were undertaken. The obtained test and numerical results were compared with nominal resistances predicted from the American, Australian/New Zealand and European design standards for stainless steel structures. Moreover, the provisions in the North American Specification for cold-formed steel members were also evaluated. The comparison results indicate that the codified design provisions are generally safe to use for design of cold-formed stainless steel RHS members undergoing combined bending and web crippling, among which the European provision yields overly-conservative predictions. The codified web crippling-bending interaction curves can be applied for designing the stainless steel RHS members undergoing combined bending and web crippling, whilst improved predictions could be achieved by employing recently proposed bending and web crippling design rules.
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