Actual Yield Strength Research Articles

Achieving high mechanical performance of the large-scale sand-casting Mg–4Y–x nd–y Gd–0.4Zr alloys by tailoring Nd and Gd contents

This research meticulously investigates the effects of varying contents of Nd and Gd, along with various heat treatment conditions, on the microstructure and mechanical characteristics of Mg–4Y-Nd-Gd-0.4Zr (wt.%) alloys within the commercial WE43 series, aiming to enhance mechanical performance while minimizing production costs. Findings reveal that Mg–4Y-1Nd-2Gd-0.4Zr alloy exhibits superior mechanical performances after undergoing a solution treatment at 500 °C for 14 h followed by peak-ageing at 200 °C for 120 h. Specifically, the ultimate tensile strength of 342.1 ± 4.9 MPa for the peak-aged Mg–4Y-1Nd-2Gd-0.4Zr alloy exceeds those of Mg–Y series alloys previously reported. The contribution of grain boundary, solid solution and precipitation strengthening is calculated to be 26.2 %, 17.3 %, and 56.5 % of actual yield strength in the peak-aged Mg–4Y-1Nd-2Gd-0.4Zr alloy, respectively, indicating that the precipitates β′ have an ascertainable influence on the yield strength. During deformation the basal slips could be effectively arrested by the prismatic β′ precipitates, leading to the augmentation of mechanical performance.

Cyclic loading tests and numerical modeling of concrete-filled 700 MPa high-strength steel tubes incorporating deep plasticity

Concrete-filled high-strength steel tubes (CFHST) could improve structural efficiency with lighter weight and higher capacity. However, the relative lower ductility and higher yield-to-tensile strength ratio of high-strength steel arouse worries about seismic performance of CFHST. In order to reveal the influence of high-strength steel on the elastoplastic hysteretic behavior of CFHST, 8 cantilever columns with Q550 and Q690 steel were subjected to constant axial load and cyclic top displacement. The actual yield strength of the steel was over 700MPa and the maximum axial load ratio was over 0.5. Based on the experimental observations, a finite element model was developed in ABAQUS that could consider deep plasticity behavior of CFHST members more precisely by introducing full-range elastoplastic constitutive model of high-strength steel and damaging–crushing behavior of infill concrete. The model was validated by the 8 tests of this study and other 34 cyclic-loaded CFST specimen from different researchers. 288 cyclic-loaded CFHST models were simulated by the effective numerical model in the parametric study on the elastoplastic deformation capacity of CFHST columns. The experimental and numerical investigations show that the CFHST could still have considerable deformation capacity if the local deformation of the steel tubes develop moderately. For heavy loaded CFST columns, high-strength thin-walled steel tubes have satisfying elastoplastic deformation capacity and ductility that are not worse than CFST with thick conventional steel tubes. The application of high-strength steel could delay the steel yield and control the damage of the concrete, leading to larger pre-peak deformation capacity. Finally, the empirical formulas were proposed to roughly yet efficiently estimate the ultimate drift θu of cyclic-loaded CFSTs with fy=345∼ 690 MPa, fc’=24∼72 MPa, ξ=1.0∼6.0 and n=0.20∼0.80, which is fairly practical in plastic inter-story-drift check and seismic design of CFHST structures.

Hydrogen stress cracking of Alloy 716 under cathodic protection—root cause analysis, and an evaluation of quality control methods

A subsea fastener made of Alloy 716 (UNS N07716) experienced a brittle fracture in service. The investigations described herein suggested that the failure was caused by hydrogen stress cracking (HSC), thus, adding to the number of reported HSC incidents on precipitation hardened nickel-based alloys over the last two decades. Incremental step loading testing on notched tensile specimens showed a net section threshold stress of <44% of the fastener materials actual yield strength. X-ray diffraction revealed that the grain boundary (GB) precipitates were predominantly the σ–related precipitate F-phase, which were suggested to have a detrimental effect on HSC resistance—even in low amounts. The low amounts of GB precipitates were indicated by a low degree of sensitization in the double-loop electrochemical potentiokinetic reactivation test. Two additional heats from the same alloy were investigated to elucidate the effect of different GB precipitates on HSC resistance and to evaluate quality control methods that are discussed in the research community.

CO2-SCC in Flexible Pipe Carbon Steel Armor Wires

Carbon dioxide-induced stress corrosion cracking (CO2-SCC) is an environmentally assisted corrosion cracking phenomenon that has recently been identified as a new failure mode in flexible pipe armor wires. The phenomenon has been observed to take place notably in severe CO2 environments and is a cause of great concern to the flexible pipe industry. As its detection, a diverse and extensive testing program has been established to develop an understanding of the phenomenon and define safe application limits for carbon steel wires to prevent the initiation of CO2-SCC. Several different testing methodologies have been explored and small-scale laboratory testing has played an instrumental role in this overall effort. This paper focuses on the results from three different small-scale testing methodologies and the impact of different parameters such as CO2 fugacity, temperature, and confinement that play a crucial role in the initiation of CO2-SCC. Furthermore, careful prominence has been given to the test setup and methodology that has been rigorously developed over the last few years. With this developed protocol in place, CO2-SCC has been effectively reproduced on all wire grades in a small-scale testing environment. Results have also shown that for a CO2 fugacity greater than 15 bar and applied stress at 100% of the actual yield strength, all existing wire grades are susceptible to CO2-SCC thus creating significant limitations to flexible pipe design with respect to this new failure phenomenon.

Mechanical integrity of tubing string in high‐temperature and high‐pressure ultra‐deep gas wells based on uncertainty theory

AbstractDuring the manufacturing process of tubing and casing, manufacturing deviations can occur in quality parameters, such as yield strength, outer diameter, and wall thickness, which can lead to uncertainty in the actual strength of the tubing string. Specifically, tubing string failures periodically occur in high‐temperature, high‐pressure, and ultra‐deep gas wells owing to the uncertainty in string strength, attenuation of high‐temperature material properties, and influence of complex load fluctuations. Therefore, in this study, Monte Carlo method is adopted to simulate the local fluctuation of downhole actual load, and the load variation rule of tubing string in high‐temperature and high‐pressure ultra‐deep well is obtained. By considering the effect of manufacturing tolerance and corrosion, variation law of string strength is obtained. Additionally, the influence of load, temperature, manufacturing tolerance, and other uncertainties on the strength and stress of the tubing string is analyzed, and a quantitative evaluation method for the mechanical integrity of the tubing string is established. The calculation results show that the uncertainty of complex loads and influence of high temperature increase the failure probability of the mechanical integrity of tubing string. Furthermore, a failure risk can potentially exist under conditions wherein conventional verification results denote no failure. It is determined via sensitivity analysis that temperature, corrosion rate, and steel grade are the main factors for the failure of the tubing string mechanical integrity. By considering the influence of high temperature, the failure probability of the tubing string is increased by 25.33% when compared to the original basis. However, considering the manufacturing tolerance of tubing string, the actual yield strength of tubing string is higher than the nominal yield strength, which reduces the failure probability of the tubing string. This implies that reduction of the subjective influence in the risk assessment process can lead to precise and quantitative analysis of the failure risk of the tubing string mechanical integrity and optimization of the structure of the tubing string in high‐temperature, high‐pressure, and ultra‐deep gas wells.

Sulfide Stress Cracking (SSC) of Low Alloy Linepipe Steels in Low H<sub>2</sub>S Content Sour Environment

Resistance to Sulfide Stress Cracking (SSC) caused by local hard zones of pipe inner surface has been required in low alloy linepipe steel. In this study, using two samples with different surface hardness, the detailed SSC initiation behavior was clarified by four-point bend (4PB) SSC tests in which immersion time and applied stress were changed in a sour environment containing 0.15 bar hydrogen sulfide (H2S) gas. SSC cracks occurred when the applied stress was higher than 90% actual yield strength (AYS) in higher surface hardness samples over 270 HV0.1. From the fracture surface observation of SSC crack sample, it was found that the mechanism gradually shifted from active path corrosion (APC) to hydrogen embrittlement (HE), and that the influence of APC mechanism remained partially in the process of SSC initiation at the tip of corrosion pit or groove. The polarization measurement in the 4PB SSC test showed that the anodic and cathodic reactions (especially cathodic reactions) were activated when the applied stress was 90% AYS or higher. The FEM coupled analysis simulating the stress and strain concentration at the bottom tip of the corrosion groove and the hydrogen diffusion and accumulation was carried out. The principal stress in the tensile direction showed the maximum value at 0.04-0.06 mm away from the tip of the corrosion groove, and the hydrogen accumulation became the maximum. It was analytically found that the SSC crack initiated and propagated with HE mechanism dominated type when the threshold value of about 0.82 ppm is exceeded.

Modeling of elastic-plastic deformation of the ring parts as applied to the analysis of the results of testing the material of the fuel-element cladding

An analytical formula for a smooth description of the tension diagram of EK-181 steel and a method for rearranging the diagram when changing the direction of deformation are proposed for the first time. The process of straightening a quarter of an annular sample and further stretching is numerically modeled. It is shown that the conditional yield strength of the material of the straightened sample is 7.5% less than the actual conditional yield strength of steel. It is shown that the test for pure bending of a cantilever sample in the form of a semicircle with the processing of the bending diagram (by analogy with GOST 3565–80 for torsion) provides an estimate of the conditional yield strength which is 32% higher than the actual yield strength. The possibility of numerical reconstruction of the tension diagram from the diagram of pure bending of a cantilevered semi-ring sample is proved. It is shown that this procedure really gives the value of the conditional yield strength of steel EK-181 with a tolerance for the residual deformation of 0.2%. The analysis of the test procedure for the rings of fuel element cladding and the proposed algorithm for determination of the conditional yield stress of the ring material is carried out. Attention is drawn to the arbitrariness of the choice of the designed load on the two-stage diagram of the diametrical tension of the ring and to the lack of scientific substantiation of the possibility of determining the yield stress on the second part of the diagram. It is shown that this method in the current form contradicts GOST for tensile testing due to the absence of a base with a uniform stress state on the ring. Therefore, the considered method is not recommended for determining the values of the conditional yield strength suitable for strength calculations.

Lateral cyclic testing and backbone curve development of high-strength steel built-up box columns under axial compression

The AISC 341 (2016) has a more stringent width-to-thickness (b/t) limit for highly ductile hollow box columns (HBCs) than the AIJ (2010) or Taiwan Code (2010), resulting in significant thickness difference in design. Moreover, the cyclic backbone curves based on ASCE 41 (2013) and NIST (2017) underestimate the post-buckling flexural strength of HBCs, particularly in high axial compression force. This paper presents test results of six full-scale, built-up HBCs using SM 570 M steel with the actual yield strength of 460–530 MPa. The lateral cyclic behavior of built-up columns was studied in terms of different b/t ratios, magnitudes of axial compression forces, and lateral drift histories (i.e., cyclically symmetric versus near-fault displacement histories). The built-up box columns were 290–400 mm wide with b/t ratios from 11 to 21, 4000 mm high, and tested laterally with both ends fixed after under a constant axial compression force, 2591–7935 kN. The HBC specimens which were designed based on the highly ductile member requirement in AISC 341 (2016), even under an axial compression force (=40%Py), performed satisfactorily at 4% drift and experienced flange and web fracture at 5% drift. However, the HBC specimens that satisfied the most compact b/t requirement in AIJ (2010) or Taiwan code (2010) did not perform well at 4% drift, losing the axial capacity after significant column local buckling and shortening. The gathered test data, supported by more test data in this work, were analyzed by a multiple regression method to obtain empirical formulations for predicting the maximum column moment, plastic rotation and post-yield hardening parameters. The proposed formulation reasonably predicts the first-cycle envelope curves of built-up HBCs, improving prediction results based on ASCE 41 (2013) and NIST (2017).

Application of nanoindentation to evaluate the hardness and yield strength of brass joints produced by FSW: microstructural and strengthening mechanisms

Nanoindentation test was employed to measure the actual hardness and yield strength of the stir zone in the friction stir-welded single-phase brass joints. For this aim, different joints were prepared according to an experimental matrix based on the central composite rotatable design. In this design matrix, the tool rotational speed, tool traverse speed, and tool axial force were the input parameters. The outputs were the hardness and yield strength of the joints. To measure the hardness and tensile strength of the joints, the nanoindentation test was employed. Moreover, electron back scattered diffraction and transmission electron microscopy techniques were used to study the microstructural features. The results showed that by decreasing rotational speed and axial force, and by increasing the traverse speed, the hardness and yield strength of the joints were increased. In other words, lower heat inputs caused higher strength in the joints. Finer grain sizes, larger grain average misorientation amounts, i.e., existence of more dislocations, and greater Taylor factors in the lower heat input joints revealed that the influence of grain boundaries, dislocations, and texture were the origins of better mechanical properties.

High-strength steel reinforced squat UHPFRC shear walls: Cyclic behavior and design implications

Ultra-high performance fiber reinforced concrete (UHPFRC) is characterized by ultra-high compressive strength and ductile tensile strain hardening behavior accompanied by dense fine cracks. This study experimentally investigated the seismic behavior of squat UHPFRC shear walls. For this purpose, four squat shear walls were tested under displacement reversals, with the experimental variables including the strength of steel reinforcement, shear stress demand for the wall, steel fiber, and dowel bar. In particular, the performance of squat UHPFRC shear walls reinforced with high-strength steel rebar with an actual yield strength above 685MPa was explored. The seismic behaviors of the squat walls were evaluated using various performance measures, such as the hysteretic response, steel reinforcement strain, stiffness, strength, energy dissipation capacity, and detailed displacement component. The results revealed that the presence of steel fibers enhanced the strength, confinement, and crack-width control ability of squat UHPFRC shear walls, allowing the walls to exhibit ductile flexural-dominant behavior even when the shear stress demand for the wall was 20% greater than the code-specified maximum allowable value. Furthermore, the proposed novel squat shear wall not only took advantage of the ultra-high mechanical properties of high-strength steel and UHPFRC materials, but also resolved the concern of the potential premature failure modes for high-strength reinforcement and concrete.

Определение составляющих силы резания при точении в зависимости от механических свойств обрабатываемого материала

Cited in the reference literature, empirical formula is usually acceptable for standard materials processed. When new materials have to repeat the experiments again. The article presents the analytical relationships derived from the generalization of the work of Russian and American scientists, in particular: VF Bobrov, NI Lvov, VS Kushner, a Merchant ME, Astakhov, V.P. These relationships relate the values of the components of the cutting force with time and the actual yield strength of the material being processed, making it much easier to calculate the components of the experiment of cutting force in turning based on the radius of curvature of the cutting edge and tool wear on the rear surface. Shrinkage factor chips taken approximately equal to one. Experimental verification showed acceptability found dependences for practical use, particularly important in the processing of materials of new brands.

Fatigue testing and analysis of cathodically protected notched specimens tested in a fully aerated aqueous 3.5% NaCl solution

Fatigue test results of notched low alloy steel specimens tested in a fully aerated aqueous 3.5% NaCl solution with cathodic protection (CP) are presented. A CP potential of −1050mV Ag/AgCl was used. This work extends the testing presented in Wormsen et al. (2015a, 2015b, 2015c), covering fatigue testing of smooth and notched low alloy steel specimens tested in-air and smooth specimens tested in 3.5% NaCl with CP. The specimens were machined from material cut from a hollow, thick-walled AISI 8630M low alloy steel forging with an actual yield and tensile strength of 632MPa and 771MPa, respectively. The reduction in fatigue life for the notched specimens tested in the 3.5% NaCl solution with CP relative to air was found to be consistent with the reduction in fatigue life for the smooth specimens in Wormsen et al. (2015b). It is considered that a design S-N curve for seawater with CP can be constructed from the smooth specimen in-air S-N curve using an environmental reduction factor of 2.5 (HSE, 1999; BS 7608, 2014) for subsea components of this steel subjected to high cycle variable amplitude loading. The fatigue test results seem to indicate that a larger environmental reduction factor may be required for constant amplitude loading when the maximum stress in the cycle is higher than the yield stress.

Investigation of stress corrosion cracking behavior of super 13Cr tubing by full-scale tubular goods corrosion test system

In this paper, a self-built device called “full-scale tubular goods corrosion test system” was used to test a 6m length super 13Cr tubing (with coupling) to study its corrosion performance in spent acid. The specimen fractured at the tubing and was investigated by visual inspection, optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and mechanical test. It was the joint function of tensile force (78.6% actual yield strength), inner pressure (70Mpa) and spent acid that induced stress corrosion cracking (SCC) of the tubing at 120°C. Three different areas were found on the fracture surface, including crack initiation area, crack expansion area, and final fracture area. The fracture initiated from the “X” shape corrosion cracks which were evolved from small corrosion pits. The reduction of ductility and toughness may also facilitate SCC of the tubing.

Effects of Surface Modification and Bulk Geometry on the Biotribological Behavior of Cross-Linked Polyethylene: Wear Testing and Finite Element Analysis.

The wear and creep deformation resistances of polymeric orthopedic bearing materials are both important for extending their longevity. In this study, we evaluated the wear and creep deformation resistances, including backside damage, of different polyethylene (PE) materials, namely, conventional PE, cross-linked PE (CLPE), and poly(2-methacryloyloxyethyl phosphorylcholine)- (PMPC-) grafted CLPE, through wear tests and finite element analysis. The gravimetric and volumetric degrees of wear of disks (3 or 6 mm in thickness) of these materials against a cobalt-chromium-molybdenum alloy pin were examined using a multidirectional pin-on-disk tester. Cross-linking and PMPC grafting decreased the gravimetric wear of the PE disks significantly. The volumetric wear at the bearing surface and the volumetric penetration in the backside of the 3-mm thick PE disk were higher than those of the 6-mm thick PE disk, regardless of the bearing material. The geometrical changes induced in the PE disks consisted of creep, because the calculated internal von Mises stress at the bearing side of all disks and that at the backside of the 3-mm thick disks exceeded their actual yield strengths. A highly hydrated bearing surface layer, formed by PMPC grafting, and a cross-linking-strengthened substrate of adequate thickness are essential for increasing the wear and creep deformation resistances.

Corrosion behavior about tubing steel in environment with high H2S and CO2 content

The corrosion behavior of C100 steel in simulated environments with high H2S and CO2 content was studied through high-temperature and high-pressure autoclave, and the H2S stress corrosion cracking (SSC) resistance of C100 steel was evaluated by SSC tests. Scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD) technique were employed to characterize the corrosion products and the metal matrix. The results indicate that all of the corrosion products in this investigation are mainly composed of different types of iron sulfide such as Fe0.95S, FeS0.9, Fe0.985S, Fe7S8 and FeS, and the absence of iron carbonate in the corrosion scales suggests that the corrosion process is governed by H2S corrosion. The corrosion rate decreases in the initial stage and then increases with the enhancement of the temperature. There exists a minimum corrosion rate at about 110 °C. Under the partial pressure of H2S lower than 9 MPa, the corrosion rate decreases with the increase of \(P_{H_2 S} \) While over 9 MPa, a higher \(P_{H_2 S} \) will result in a faster corrosion process. When the applied stress is 72%, 80% and 85% of actual yield strength (AYS), all tested specimens show no crack, which reveals a superior SSC resistance.

The Experiment Research of Corrosion Behavior about Tubing Steel in Environment with High H<sub>2</sub>S and CO<sub>2</sub> Content

The corrosion behavior of C100 steel in simulated environments with high H2S and CO2 content was studied through high-temperature and high-pressure autoclave, and the H2S stress corrosion cracking (SSC) resistance of C100 steel was evaluated by SSC tests. Scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD) technique were employed to characterize the corrosion products and the metal matrix. The results indicate that all of the corrosion products in this investigation are mainly composed of different types of iron sulfide such as Fe0.95S, FeS0.9, Fe0.985S, Fe7S8 and FeS, and the absence of iron carbonate in the corrosion scales suggests that the corrosion process is governed by H2S corrosion. The corrosion rate decreases in the initial stage and then increases with the enhance of the temperature. There exists a minimum corrosion rate at about 110°C. Under the partial pressure of H2S lower than 9MPa, the corrosion rate decreases with the increase of P . While over 9MPa, a higher P will result in a faster corrosion process. When the applied stress is 72 %, 80 % and 85 % of actual yield strength (AYS), all tested specimens show no crack, which reveals a superior SSC resistance. The precipitation of the second phase particles at the grain boundary or in crystal grain, the dislocation tangle and the dislocation pinning of the dispersion carbonide hinder the SSC cracks to propagate.

Material Testing and Evaluation of Steel Mechanical Properties for Classification of Steel Grade of Existing Civil Engineering Structure

The paper is generally focused on the determination and evaluation of yield and ultimate strengths of structural steels, not only current materials but also materials of existing steel structures when the properties are unknown and no material certificates exist. The attention is paid i.a. to the testing and evaluation of steel strengths, especially from the viewpoint of the statistical elaboration of material test results aimed to obtain strength values leading to the reliable structural design [3], in the meaning of general rules according to the European Standards for structural design of civil engineering constructions. The paper deals with actual yield and ultimate strengths obtained using material tests and with characteristic and design strengths based on the test results evaluation versus nominal and design strengths given by European Standards which are used for the structural design in the usual cases when steel grade is known. But in the case of existing structures, very often no information about the material exist that actual values of steel properties shall be determined using material tests and their statistical elaboration to obtain such values of steel properties which lead to the reliable structural design [3], [6], [7]. However, approaches of the derivation of characteristic and design steel strengths using actual test results are principally different from the consideration of nominal and design steel strengths covered by the rules of the European Standards. This paper illustrates the evaluation of the results of material tests performed on the test specimens taken from the steel roof structure of the sport stadium almost 50 years aged, within the diagnostics of load-carrying steel structures of this building [1] aimed to the evaluation of the existing construction [2].

Classification of Structural Steel of Existing Civil Engineering Structure Based on Testing and Evaluation of Yield and Ultimate Strengths

The paper is generally focused on yield and ultimate strengths of structural steels. The attention is mainly paid to the testing and subsequent determination of steel strengths, especially from the viewpoint of the statistical evaluation aimed to obtain the strength values leading to the reliable structural design, in the meaning of general rules given by the European Standard for the structural design of civil engineering constructions. The presented paper deals with the actual yield and ultimate strengths obtained from material tests and their characteristic and design values based on the test results evaluation, versus nominal and design values considered according to European Standard rules and used for the structural design in the usual cases if the steel grade is known. But in the case of existing constructions, sometimes there are no information about the material that the actual steel properties shall be determined using the material tests and their statistical evaluation to obtain such steel properties values which can lead to the reliable structural design. However, approaches of the determination of characteristic and design steel strengths using actual test results are different from the determination of the nominal and design steel strengths given by standard rules. As an illustration the paper summaries the results and evaluations of tests of structural steel performed on the specimens taken from the load-carrying roof structure of the sport stadium aged about 40 years, within the steel construction diagnostics.

An extended evaluation for the shear behavior of hollow tubular flange plate girders

In this paper, an extended numerical investigation is conducted to study the shear behavior of transversely stiffened hollow tubular flange plate girders (HTFPGs) using ABAQUS software. A comparison between the HTFPGs and plate girders with flat flange plates (IPGs) is first made considering the elastic-buckling and the post-buckling strength. The results indicated that the realistic support condition at the juncture of the web and flanges of HTFPGs is nearly fixed. The study is then extended to examine hybrid HTFPGs (HHTFPGs). The main goal of this extension was to examine the validity of the current EN 1993-1-5 provisions regarding both the shear resistance and the behavior trend of such hybrid girders. The validity of the other international design codes such as the AASHTO, AISC and BS 5950 were also checked. The results of the finite element (FE) models confirmed that using HHTFPGs provides economy as their strength could be utilised efficiently. In addition, it was found that the strengths obtained with EN 1993-1-5 provisions do reproduce suitably the trends obtained numerically, but their design equations were found to be extremely conservative. Moreover, the shear strength recently proposed for homogenous HTFPGs seemed to be slightly conservative for the case of HHTFPGs. Therefore, it was modified herein by taking the relative effect of the actual flange yield strength into account. This shear strength currently modified is found to represent the actual behavior of these girders better than the original and recently proposed EN 1993-1-5 shear strengths. Several remarks regarding the selection of optimum dimensions for the HTFPGs are also presented.

Seismic performance evaluation of moment resisting frames using high performance steel

A new high quality steel material (SN) was developed by reducing the distribution at yield point. This steel material has an advantage of having accurate yield strength compared to regular steel materials (SS and SM). Therefore, by using SN steel, the collapse mechanism can be controlled as intended for design. SS, SM, and SN steel materials were tested, and variations of yield strengths were investigated. The effect of having dispersed yield strength was investigated by conducting experiments on 8 test specimens. Column to beam yield strength ratio was changed from intended column to beam yield strength ratio because of the difference between the specified minimum yield stress and the actual yield strength of the steel materials, and it affected the collapse mechanism and the overall behavior of the specimen. It was verified through static cyclic test and static pushover analysis that the seismic performance of buildings designed using SS and SM steel could be decreased by as much as 20% compared to using SN steel. It is observed that the provision of upper bound limit on yield point in SN steel is effective in securing seismic performance of steel buildings.