High Performance Steel Research Articles

Mechanical properties, flexural behavior, and chloride permeability of high-performance steel fiber-reinforced concrete (SFRC) modified with rice husk ash and micro-silica

To improve the fiber-matrix bond and enhance the macro-mechanical performance of SFRC, this study is focused on the modification of the cement matrix by using two eco-friendly supplementary cementitious materials (SCMs), rice husk ash (RHA) and micro-silica (MS). The modification effects of SCMs on the steel fibers were observed and characterized by conducting several macro-mechanical tests i.e., compressive strength, splitting tensile strength, and load-deflection behavior. Besides that, ultrasonic pulse velocity, water absorption, and chloride migration tests were performed to characterize the durability of modified SFRC mixes. The results showed that the incorporation of RHA and MS at low levels notably enhanced the efficiency of steel fibers under splitting tensile and flexural strength testing. SFRC made with 7.5% MS and 7.5% RHA showed 79% and 96% more flexural strength than plain concrete (PC), respectively. Whereas SFRC experienced 14% and 26% further improvement in flexural toughness with the addition of 7.5% RHA and 7.5% MS, respectively. The addition of 7.5% and 12.5% RHA showed a beneficial effect on the resistance of SFRC against the penetration of chloride ions and water. The results of this study confirmed the synergistic interaction of steel fiber and SCMs.

Gas-phase aluminizing of HP40Nb steel used in reformer tubes: Synthesis, characterization, and its implications for the microstructure and high-temperature creep resistance of the base alloy

This study investigates the microstructure and creep behavior of gas-phase aluminized High-Performance (HP40Nb) steel. Microstructures of coated and base alloy were examined by electron and optical microscopes. Gas-phase aluminizing of HP steel resulted in the formation of a top AlNi layer over an interdiffusion zone (IDZ) on the base alloy. Results also showed that there were hardly any cavities or discontinuities formed in top layer and IDZ during the aluminizing process. The creep test results showed that the gas-phase aluminized steel had significantly a higher minimum creep rate and consequently a shorter time-to-rupture, as compared to uncoated HP40Nb steel. Microscopic examinations revealed that the main reason for the fracture of the steel after the creep test was formation of micro-cavities in the vicinity of carbides and growth of micro-cracks along the grain boundaries and alongside inter-dendritic areas. Also, fractography analysis showed that a quasi-cleavage fracture had occurred for both coated and uncoated steel. The implication of gas-phase aluminizing on creep resistance of coated HP40Nb steel, and its interrelation between the microstructure and observed mechanical properties are discussed and explained through the paper.

Experimental study on triple grades hybrid high-performance steel structure (TGHSS): Members and joints

The triple grades hybrid high-performance steel structure (TGHSS) is an innovative structural system with excellent seismic behaviour proposed by the authors. The TGHSS comprises high strength steel columns, ordinary strength steel beams, and low yield point steel buckling-restrained braces (BRBs). In full-scale cyclic tests on eight single-bay two-story specimens, strains on surfaces of beams, columns, and joints were extensively monitored, and deformations of BRBs at both stories were recorded. The global responses of TGHSSs were introduced and discussed in the first companion paper. This paper focuses on the local responses of members and joints under real boundary conditions in structures, which is deemed to provide more reasonable performance evaluations than independent tests on extracted specimens. The force analyses of beams, columns, and joints were conducted. The hysteresis behaviour, mechanical indexes, energy dissipation, and end rotation of BRBs were studied. Moreover, the plastic development sequences were obtained and discussed following the above contents. Results showed that the low yield point BRBs could provide reliable cyclic behaviour and energy dissipation with the cumulative ductility factor of 312.03 ∼ 1191.74, meeting the requirement in American and Chinese codes. The ordinary strength steel beams produced plastic hinges with considerable rotations of at least 0.02 rad. The high strength steel columns exhibited limited plasticity, especially the panel zones in beam-to-column joints almost kept elastic. Results revealed that the TGHSS featured a sequential plastic development as expected from BRBs to beams and then to columns. Following the test results, some design suggestions were proposed for TGHSSs.

Mechanical performance and numerical simulation of high-performance steel fiber reinforced concrete

This paper presents the outcome of the investigation of high-performance steel fiber reinforced concrete (HP-SFRC) with water to binder ratio (w:b) of 0.30- 0.40. The binder included cement replacement of 10 and 15% by silica fume. Fiber volume fractions (Vf) of 0, 0.5, 1.0 and 1.5% with aspect ratios of 80 and 53 were used. The study aims to present the effect of the inclusion of micro-silica and steel fibers on the mechanical performance of HP-SFRC. Experimental results show that moderate increase in compressive strength and significant improvement in flexural strength of HP-SFRC at Vf = 1.5% (reinforcing index = 3.88) with 15% micro-silica replacement. Empirical expressions were developed for compressive and flexural strength of HP-SFRC as a function of steel fiber volume fraction. The power relation between flexural tensile and compressive strengths was developed with an integral absolute error of 6.39. Further, the validity of the proposed models was tested against published data. A machine learning framework was established based on an adaptive neuro-fuzzy inference system (ANFIS) to predict the compressive strength of HP-SFRC mixes with higher accuracy. Finally, a multiple linear regression (MLR) model is proposed for the strength of HP-SFRC mixes and tested against published data. The validity of the MLR model is checked with experimental results and it is shown that the model has good prediction capability.

Approach to Estimate the Phase Formation and the Mechanical Properties of Alloys Processed by Laser Powder Bed Fusion via Casting.

A high-performance tool steel with the nominal composition Fe85Cr4Mo8V2C1 (wt%) was processed by three different manufacturing techniques with rising cooling rates: conventional gravity casting, centrifugal casting and an additive manufacturing process, using laser powder bed fusion (LPBF). The resulting material of all processing routes reveals a microstructure, which is composed of martensite, austenite and carbides. However, comparing the size, the morphology and the weight fraction of the present phases, a significant difference of the gravity cast samples is evident, whereas the centrifugal cast material and the LPBF samples show certain commonalities leading finally to similar mechanical properties. This provides the opportunity to roughly estimate the mechanical properties of the material fabricated by LPBF. The major benefit arises from the required small material quantity and the low resources for the preparation of samples by centrifugal casting in comparison to the additive manufacturing process. Concluding, the present findings demonstrate the high attractiveness of centrifugal casting for the effective material screening and hence development of novel alloys adapted to LPBF-processing.

Wire and arc additive manufacturing fabrication of ODS-RAFM steels and preliminary evaluation on microstructures and mechanical properties

Oxide-dispersion-strengthened reduced-activation ferritic/martensitic (ODS-RAFM) steels have promising applications in future fusion reactors, but the rapid and cost-efficient fabrication of ODS-RAFM steel components still remains a major challenge. In this study, wire and arc additive manufacturing (WAAM) techniques were developed to fabricate a thin-wall ODS-9Cr-RAFM steel part, using flux cored wires containing nano-Y2O3 as the [Y] and [O] sources and Ti as micro-alloying element. Their microstructures and mechanical properties before and after austenite-quenching were both investigated, and the results were compared with other 9Cr-RAFM counterparts without the addition of nano-Y2O3 and Ti. It was suggested that Y2O3 could decompose into [Y] and [O] during the rapid melting, and then precipitate along with Ti as Y2TiO5 mostly (and perhaps also TiO2) during the rapid solidification of WAAM. These oxides have fine nano-sizes with a high number density and can provide multi-fold benefits from refining the grain/sub-grain structures, promoting martensite transformation, to pinning dislocations. After the aus-quenching, a new, more stable nano-phase of Y2Ti2O7 was formed, with combined features of ultra-fine size, high number density, and high coherency. The as-quenched ODS-9Cr-RAFM specimens can achieve markedly high strengths with good plasticity, both at room temperature and elevated temperatures up to 650 °C, showing great promises of WAAM techniques for large-scale fabricating high-performance ODS-RAFM steel structural components.

Investigation of the correlation between MBN signatures of low carbon content martensitic steels and their tensile properties

Nondestructive testing (NDT) of industrial steel products is commonly used to detect defects such as cracks using among other methods, electromagnetic techniques. When properly calibrated, these NDT can be adapted to evaluate the mechanical properties of steels. It is especially of prime importance when rigorous quality control must be achieved for high performance steels. In this context, the proposed article deals with the investigation of the Magnetic Barkhausen Noise (MBN) to characterize the tensile properties of high mechanical performance martensitic steels.

Crack-free in situ heat-treated high-alloy tool steel processed via laser powder bed fusion: microstructure and mechanical properties

In this study, high-alloy tool steel S390 was processed crack-free and dense for the first time using laser powder bed fusion (LPBF). The resulting mechanical properties and microstructure of the LPBF steel parts were investigated. High-alloy tool steels, such as high-performance high-speed Boehler S390 steel (containing 1.64 wt% C and W, Mo, V, Co, and Cr in the ratio 10:2:5:8:5 wt%), are prone to cracking when processed using LPBF because these steels have high carbon and carbide-forming alloying elements content. Cracks are induced by thermal stresses and solid-phase transformation, combined with weak grain boundaries caused by segregated primary carbides. Substrate plate heating reduces thermal stresses and enables in situ heat treatment, thus modulating solid-phase transformation and carbide precipitation and preventing cracking during cooling. The resulting microstructure, precipitations, and mechanical properties of the as-built LPBF specimens, which were in situ heat-treated at 800 °C, and the conventionally post-heat-treated specimens were assessed using optical microscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron backscatter diffraction, X-ray diffraction, hardness testing, bending testing, and density measurement. In situ heat treatment impacts microstructure, precipitation behavior, and solid-phase transformation, causing a change in the microstructure of the material along the build direction due to different thermal histories. The as-built specimens exhibit a hardness gradient along the build direction of 500 HV1 to 800 HV1 in the top layer. The average bending strength is 2500 MPa, measured from the tensile stresses on the harder side and the compressive stresses on the softer side. Conventional post-heat treatment yields a mean hardness of 610 HV1 and a mean bending strength of 2800 MPa.

Synergistic optimization in microstructure and mechanical properties of low carbon steel via trace amount of nano-sized TiC-TiB2

The current research studied the microstructure and mechanical properties of low carbon steels reinforced by a trace amount of TiC-TiB 2 nanoparticles. An innovative method was proposed to introduce the nanoparticles into molten iron through the use of an aluminum master alloy. It was found that the addition of nanoparticles refined the grains and lamellar structures in pearlite of low carbon steels. During the liquid-solid phase transformation, the amount of widmanstatten structures containing acicular ferrite decreased after adding the nanoparticles. For mechanical properties, the simultaneous enhancement of hardness, tensile properties and impact toughness of low carbon steels was achieved. According to the edge-to-edge matching model, it was found that the nanoparticles could be utilized as heterogeneous cores to facilitate the nucleation of austenite and ferrite. A higher nucleation rate resulted in finer microstructure under as-cast and annealed conditions. Moreover, the enhanced yield strength and tensile strength were attributed to the inhibition of migration of dislocations due to more grain boundaries and the nanoparticles. The enhanced ductility and toughness were associated with the fine microstructure and scattering behavior of cracks by the nanoparticles. These results can be used as references in the development of high-performance steels by using the nano-sized ceramic particles. • Nanoparticles-reinforced low carbon steels were prepared by using a TiC-TiB 2 /Al master alloy. • The as-cast and annealed microstructures were refined by adding TiC-TiB 2 nanoparticles. • The mechanical properties were simultaneously enhanced by adding TiC-TiB 2 nanoparticles. • An E2EM model indicated that the nanoparticles could be utilized as heterogenous cores.

Seismic behaviour of stainless-clad bimetallic steel welded box-section beam-columns

The stainless-clad (SC) bimetallic steel is an advanced high-performance steel with high strength and outstanding corrosion-resistant performance. It is especially competitive in the application of structures with demands of high corrosion resistance. However, the current research on SC bimetallic steels mainly focuses on the material level rather than the structural level, and it is not clear whether the excellent performance of materials can be reflected in the seismic behaviours of members. Thus, cyclic behaviours of SC bimetallic steel members need to be thoroughly investigated to fill the research gap and expand the application fields of this steel in the seismic region. To this end, this paper aims to study the cyclic behaviour of SC bimetallic steel box-section beam-columns subjected to combined constant axial load and low-cycle reciprocating lateral load through full-scale tests and finite element (FE) models. Four specimens were tested, and the influence of the width-to-thickness ratio of component plates was clarified through comparative research on the test processes, buckling details, hysteresis curves, strain curves, energy dissipation and ductility performance. Moreover, a refined FE model adopted single-layered modelling or double-layered modelling was developed respectively; and then, the model validation, the shear stress distribution at the bonding interface and parametric analyses were carried out. Research showed that the SC bimetallic steel beam-columns exhibit good energy dissipation and seismic behaviour under cyclic loadings; the smaller width-to-thickness ratio or axial load ratio could result in the plumper hysteresis curves, more sufficient energy dissipation and superior ductility performance; the ductility performance of SC bimetallic steel column was significantly improved; the ductility-based design approach proposed herein could approximately quantify the ductility performance of SC bimetallic steel box-section column, which could provide a reference for the seismic design.

Bearing behavior of high-performance concrete-filled high-strength steel tube composite columns subjected to eccentrical load

In order to study the bearing capacity of high-performance concrete-filled high-strength steel tube (HCHST) composite stub columns subjected to eccentrical load, 22 HCHST composite stub columns, 4 concrete-filled steel tube (CFST) composite stub columns and 8 high-performance concrete-filled steel tube (HCST) composite stub columns were designed with the cubic compressive strength of concrete (fcu), the yield strength of steel tube (fy), the thickness of tube wall (t), the eccentricity (e) and slenderness ratio (λ) as the main parameters. Considering the nonlinear constitutive model of concrete and simplified constitutive model of steel, the finite element (FE) model of HCHST composite stub columns was established by ABAQUS software. By comparison with the existing test results, the rationality of the constitutive model and boundary conditions was verified. The variation of ultimate bearing capacity and the typical failure modes of HCHST composite stub columns under different parameters was analyzed. The results show that the specimens exhibit obvious bulge outward at the end of the steel tube and shear failure at the end of concrete. High-performance concrete (HPC) can significantly improve the ultimate eccentrical compression bearing capacity of composite columns, and high-strength steel tubes have better restraint effect on HPC. With the increasing of t, the ultimate eccentrical compression bearing capacity and the load-holding capacity of HCHST columns increases gradually, while the ultimate eccentrical compression bearing capacity decreases gradually with the increasing of λ and e. By introducing the reduction coefficient of eccentricity (φ1) and the reduction coefficient of slenderness ratio (φ2), the calculation formula of the eccentric bearing capacity of HCHST columns is proposed by statistical regression, which can lay a foundation for the application of HCHST columns in practical engineering.

Development of triple grades hybrid high-performance steel structure (TGHSS): Concept and experiments

To develop an innovative steel structural system with excellent seismic performance, this paper proposed triple grades hybrid high-performance steel structures (TGHSSs), composed of high strength steel columns, ordinary strength steel beams, and low yield point steel buckling-restrained braces (BRBs). The basic concept was introduced, and then eight full-scale specimens were tested under cyclic loads to validate their seismic behaviour. All the specimens were single-bay and two-story, in which seven specimens are TGHSSs, and a benchmark specimen utilised ordinary strength steel columns for comparisons. In TGHSS specimens, columns included three grades of high strength steel (i.e., 460 MPa, 690 MPa, and 890 MPa), beams utilised 345 MPa steel, and BRBs included three grades of low yield point steel (i.e., 100 MPa, 160 MPa, and 225 MPa). Test observations and structural responses were analysed, involving failure modes, hysteresis behaviour, loading resistance, lateral stiffness, deformation responses, and energy dissipation. The results showed that the TGHSS fulfilled a sequential yielding mechanism as expected with satisfactory seismic behaviour. Specifically, the low yield point steel BRBs yielded at first (overall drift ratio 1/820-1/420) to dissipate seismic energy. Then, the ordinary strength steel beams developed plastic hinges at beam ends (approximate overall drift ratio 2%). At last, the high strength steel columns kept almost elastic or only presented limited plasticity at column bases. Results demonstrated that the proposed TGHSS has strong potential to be an alternative structural system in seismic areas and provides feasible solutions for high-performance structures made of steel having multiple strength grades.

Bonding Performance of Steel Rebar Coated with Ultra-High-Performance Concrete

In this study, to improve the bond performance of reinforcing bars fixed inside concrete, a pullout test using ultra high-performance concrete (UHPC) and structural steel fibers was conducted and a model that could predict the performance was also presented. After creating a UHPC layer on the rebar surface, the specimens were prepared along with three types of structural fibers. The structural fibers with different shapes were mixed up to 0.2%, 0,4%, 0.6%, 0.8%, 1% and 2% to analyze their effects on the bond failure at the interface. As a result of the experiment, the pullout resistance ability of the specimen thinly coated with UHPC maintained high residual stress due to the steep section reaching the maximum load, increased the maximum pullout load, and delayed the bond failure during the extraction process. As a result of the cross-sectional examination of the specimen, the coating of UHPC was strongly attached to the rebar surface and the bond surface was broken through sliding at the interface (UHPC–ordinary Portland concrete (OPC)). It was found that the increase in the structural fiber significantly improved the pulling-out resistance at the interface. The proposed model based on the existing Cosenz–Manfredi–Realfonzo (CMR) and Bertero–Popov–Eligehausen (BPE) prediction models was found to be in good agreement with the experimental results.

Numerical analysis of tunnel segments strengthened by steel–concrete composites

In order to study the feasibility of strengthening of segmental tunnel linings by using steel–concrete composites (SCC), a three-dimensional (3D) finite element (FE) model is proposed in this paper. The nonlinear mechanical behavior of concrete is described by a plastic-damage model. The nonlinearity, resulting from the interface of the SCC and reinforced concrete (RC) segments, is simulated with the help of a system of springs. The analysis results are compared with those obtained from a full-scale test of a tunnel segment. Their agreement validates the usefulness of the 3D FE model. Numerical re-analysis of the test shows that the interfacial connectors govern both the strengthening effect of SCC and the failure pattern of the strengthened segments. Thus, the force-transmitting capacity of the interfacial connectors should be concerned in design activities. As regards the circular segments, the interfacial connectors refer to both the shearing and the stripping connectors. The composite effect of the SCC and RC segments increases with the increasing number of these connectors. The latter, therefore, results in the increases of the bearing capacities and stiffnesses of the strengthened segments. Those increases become insignificant as the number of these connectors is sufficient to ensure a perfect composite effect of the SCC and RC segments. In addition, the numerical simulations show that using high-performance steel shell (HPS) or/and ultra-high-performance concrete (UHPC) is an effective way to increase the strengthening effect of SCCs.

Mechanical behavior of high-performance steel ring restrainers with negative Poisson’s ratio effect

The steel ring restrainer (SRR) is a novel restrainer for bridges, which can prevent the unseating of bridges when an earthquake occurs. The traditional SRR is commonly made of mild steel, so it has the limitation of low strength and insufficient safety margin. In this paper, a new type of high-performance steel with negative Poisson’s ratio effect (NPR steel) is introduced for use in an SRR. Finite element (FE) models of SRRs are constructed, and the credibility of the FE model is validated based on previous experiments. Then, the FE models of SRRs under the mild steel, high-strength steel, and NPR steel are established, and the mechanical performance of SRRs fabricated of different steel grades is compared. The comparison results show that the macroscopic deformation processes of SRRs made of different steel grades during operation are similar, but their mechanical properties differ. Among them, the SRR made of NPR steel (SRR-NPR) has the advantage of high strength, excellent ductility and sufficient safety margin, so it can overcome the limitations of traditional SRRs. Subsequently, in order to further explore the mechanical behavior of SRR-NPR, several FE models of SRR-NPR are supplemented by changing the design parameters. The analytical results indicate that the trends in the influence of the design parameters on the mechanical properties of SRR-NPR are similar to those of traditional SRRs. However, the sensitivity of the mechanical properties of SRR-NPR to design parameters is higher than that of traditional SRRs. Finally, based on the results of numerical analyses, the problem that the conventional method of predicting the relationship between force and displacement of SRRs is inapplicable to SRR-NPR is overcome, and prediction formulas of SRRs that considers more factors are proposed and verified.

Effect of magnesia-calcium hexaaluminate refractories on the quality of low-carbon alloy steel

High-performance alloy steel is distinguished by its purity. Inclusion contamination and oxygen addition to the steel due to long contact between the refractories of the tundish and the steel should be avoided. In this study, the static crucible method was used in the interaction experiments between MgO–CA6 composite and low carbon alloy steel. The effects of different proportions of MgO–CA6 on the content of alloying elements in steel were analyzed. Morphology, quantity, size, and distribution of inclusions were also examined. The results indicated that more inclusions (e.g., MnO, FeO, and MnS) were generated between the MgO material and alloy elements (e.g., Fe and Mn) in molten steel. The oxygen content in molten steel of CA6, MgO–0.28CA6, and MgO–0.70CA6 materials, as well as the number of inclusions, were sharply reduced. The particle size was smaller, resulting in good molten steel purification ability. The oxygen content of the steel in contact with the MgO–0.28CA6 material was relatively low, characterized by a reduction in the proportion of inclusion area and particle.

Simultaneous enhancements of strength and ductility of a selective laser melted H13 steel through inoculation treatment

Recent studies have confirmed that the high brittleness and property anisotropy of the selective laser melting (SLM) fabricated H13 tool steel are attributed to the presence of elongated, unstable high carbon γ (austenite) thin films in between the columnar structures. To overcome this problem, TiN nanoparticles (0.5 wt.%) were used as an inoculator to promote heterogeneous nucleation of the prior γ-grains, converting the columnar structure into equiaxed and refined grains. As a result, the finer α’-blocks formed upon the subsequent martensitic transformation. This not only leads to the elimination of the property anisotropy, but also simultaneously increases the strength (tensile strength of 2051 ± 48 MPa) and ductility (elongation of 7.4 ± 0.7%) of the SLM-fabricated H13 steel. The present work forms a significant step towards to fabricating high-performance tool steels using the SLM technique.

Overall buckling behaviour of superior high-performance steel columns under fire

This paper presents the experimental and numerical investigation on the overall buckling behaviour of superior high-performance (SHP) steel welded I-section columns under fire. Ten full-scale column tests with different slenderness and axial compression ratios being involved were carried out in a vertical test furnace using the transient test method. The test phenomena, failure modes, temperature-time curves, axial displacement-time curves and critical temperatures were obtained and analysed based on the test results. Finite element (FE) models were developed afterward and validated accordingly. Furthermore, comprehensive parametric study was performed to systematically clarify the effects of geometric initial imperfection, residual stress and steel grade on the critical temperature. Comparisons of the FE modelling results with Chinese and European standards indicate that the current design methods need to be modified for the use of the SHP steel. On the basis of the evaluation results, a new set of modified formulae adapting the critical temperature method are proposed in the present work.

Microstructure manipulation mechanism and mechanical properties improvement of H13 steel via trace nano-(TiC + TiB2) particles

In this study, an innovative method, wherein trace in situ synthesized nano-(TiC+TiB2) particles are added forged H13 steel, was designed and used to manipulate its microstructure. This refined the grains and laths martensite, increased the retained austenite and carbides, and controlled the carbide segregation. Thus, the strength, plasticity, and toughness of the steel were simultaneously improved. Among the samples, the H13 steel, manipulated by 0.02 wt% nano-(TiC+TiB2) particles, exhibited the best mechanical properties. Its yield strength, tensile strength, elongation, unnotched impact toughness and U-notch impact toughness increased by 11.6%, 7.6%, 14.2%, 35.0% and 33.8%, respectively, and reached 1142 MPa, 1426 MPa, 16.9%, 449.3 J/cm2, and 41.39 J/cm2, respectively. The main strengthening mechanisms were grain boundary strengthening, dislocation strengthening and dispersion strengthening. This study provides a new method for the bonding between ceramic nanoparticles and steel and provides a novel idea for the development of high-performance and low-cost steel.

Residual stress within stainless-clad bimetallic steel welded box sections

Stainless-clad (SC) bimetallic steel is a new high-performance steel which is composed of a substrate layer (CM steel) and a clad layer (stainless steel), and they are bonded metallurgically together. It is beneficial to both structural performance and corrosion resistance together with a high cost efficiency. This paper presents an experimental programme to investigate and model the residual stresses within SC bimetallic steel welded box sections. Eight box sections with various widths, thicknesses and clad ratios were fabricated and tested with sectioning method. A total of 494 strip specimens were obtained to quantify both magnitudes and distributions of welding-induced residual stresses within these sections. In each section, the maximum compressive stress is significantly smaller than those reported previously, while the compressive stress within the clad layer is much higher than the one within the substrate layer. A simplified model which ignores variations of magnitudes along the thicknesses was proposed. The distribution regions of this multi-stepped model are determined and the compressive residual stresses were found to be dependent on both widths and thicknesses of the sectional component plates. Moreover, deviation of the compressive residual stresses within the clad and the substrate layers was observed in this study, and it was demonstrated that this deviation depended significantly on the clad ratio of the bimetallic steel plates. A layered model was further established after considering these differences between these residual stresses within the two layers, in which the deviation of the compressive residual stresses within the clad and the substrate layers is found related to both the width-to-thickness ratio and clad ratio of the component plate. Two models proposed herein are shown to agree well with the measured residual stress distributions. Furthermore, numerical models were established to assess accuracy of these two models in simulating column buckling, and it showed that both the simplified model and the layered model were applicable to simulate column buckling behaviour.