MECHANICAL PROPERTIES OF STRUCTURAL STEEL AND HIGH-TENSION BOLT AT ELEVATED TEMPERATURE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Kyung-Jae Shin ◽  
Hee-Du Lee ◽  
So-Yeong Kim ◽  
Da-Som Chu ◽  
Jong-Hun Woo
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Yield Strength ◽  
Structural Steel ◽  
Elevated Temperatures ◽  
Residential Buildings ◽  
Tensile Force ◽  
Test Results ◽  
Steel Members ◽  
Reduction Factors

This paper presents the test results of the mechanical properties of three types of structural steel at high temperature, which are generally used for the Pre-Engineered Building (PEB) system. The PEB system is generally used for non-residential buildings, such as factories and warehouses. The structural steel members are installed without fire resistance protection, which means they are very weak in the case of fire. The end-plate connection could be critical in the case of fire because most of the moment is resisted by the tensile force of the bolts. Therefore, the mechanical properties of bolts at elevated temperatures are tested. Coupon test specimens for SS400(SS275), SM490(SS355), and F10T bolts were tested according to ASTM E8M. The high-temperature coupon tests were performed at 20°C, 400°C, 500°C, 600°C, 700°C, and 800°C. The test results were compared with the design reduction factors obtained from the American and European standards. The yield strength and tensile strength satisfied the minimum strength of the specified standards at 20°C. However, the reduction factor for yield strength obtained at a high temperature was lower than that of the standard value suggested by the code. In particular, the reduction factors for the high-strength bolt (F10T) were lower than those of the structural steel members (SS400(SS275), SM490(SM355)).

Modeling the Microstructural and Yield Strength Evolution of an Age-Hardenable Al Alloy for High Temperature Applications

2016 ◽  
Vol 879 ◽  
pp. 380-385 ◽  
Author(s):  
Marco Colombo ◽  
Elisabetta Gariboldi ◽  
Paola Bassani ◽  
Mihaela Albu ◽  
Ferdinand Hofer
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Yield Strength ◽  
Elevated Temperatures ◽  
Age Hardening ◽  
Homogeneous Distribution ◽  
Al Alloy ◽  
Physically Based ◽  
The Matrix ◽  
Physically Based Models

The mechanical properties of Al alloys are strongly affected by their microstructure: the size and shape of precipitates, their homogeneous distribution and their coherency with the matrix are of primary importance for an effective strengthening of the alloys at room and elevated temperatures. Physically-based models are powerful tools to predict the influence of the mentioned parameters on the mechanical properties of the alloy after age hardening, and also to predict the effect of high temperature service conditions on microstructure evolution. Scope of this work is to model the dimensional kinetic evolution of plate shaped precipitates of an Al-based alloy during aging and after different overaging times at elevated temperature, and use these results to estimate the alloy yield strength. The alloy strengthening response is due to three terms, linearly summed: the intrinsic strength of Aluminum, the contribution from solute in solid solution and the contribution arising from precipitates. The consistency of the model is verified with experimental data obtained from a 2014 Al alloy.

scholarly journals Mechanical Properties of ASTM A572 Grades 50 and 60 Steels at High Temperatures

2021 ◽  
Vol 11 (24) ◽  
pp. 11833
Author(s):  
Su-Hyeon Lee ◽  
Byong-Jeong Choi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
High Temperatures ◽  
High Strength Steel ◽  
Elevated Temperatures ◽  
High Strength ◽  
Reduction Factor ◽  
Reduction Factors

Studies involving the mechanical properties of high-strength steel (HSS) at elevated temperatures have received considerable attention in recent years. However, current research on HSS at high temperatures is lacking. As a result, the design of fire-protective steel structures with high standards is not sufficiently conservative or safe. This study investigates the effect that elevated temperatures have on the mechanical properties of ASTM A572 Gr. 50 and 60 steels. Reduction factors for the yield strength, tensile strength, and elastic modulus were derived and compared with the standard (AISC, EN1993-1-2) and previous studies (NIST). This study also provides extensive data on the reduction factors for the yield strength, tensile strength, and elastic modulus of mild steel (MS), HSS, and very-high-strength steel (VHSS). The reduction factor for the yield strength was analyzed by expanding the strain level up to 20%. Equations for the yield strength, tensile strength, and elastic modulus were proposed. In future studies, various strains should be analyzed according to the grade of the steel, with the derivation of a reduction factor that considers the plastic strain of the steel. Hence, the findings reported in this study generated a database that can be applied to fire safety design or performance-based fire-resistant design.

scholarly journals Stretch Forming Behavior and Constitutive Equation of a Modified 5083 Alloy with High Mg Content at Elevated Temperatures

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 410
Author(s):  
Seung-Yoon Yang ◽  
Da-Bin Lee ◽  
Kweon-Hoon Choi ◽  
Nam-Seok Kim ◽  
Seong-Ho Ha ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
Test Results ◽  
Stretch Forming ◽  
Temperature Conditions ◽  
Wide Range ◽  
Mg Content

For the purpose of applying a modified 5083 alloy (New 5083M alloy) with high Mg content in various automotive sheet parts, the stretch forming behavior of the 5083M alloy was studied in tensile mode at a wide range of processing conditions. The tensile tests were conducted by using a tensile test machine under the temperature ranges of 100–400 °C and the strain rate ranges of 0.001–1 s−1. The test results showed that the 5083M alloy has superior mechanical properties to that of the commercial 5083 alloy at elevated temperatures. The microstructure before and after the stretch forming was analyzed using optical microscope (OM) equipped with a polarizing filter and electron backscattered diffraction (EBSD) unit. Deformed microstructure was observed under low temperature conditions and dynamic recrystallized microstructure under high temperature conditions. However, regardless of microstructure evolution, developed deformation textures were distributed in orientation distribution functions (ODF) images. In addition, at high temperature and low strain rate condition, complex shaped cavities which were detrimental to mechanical properties appeared at the grain boundary and grain triple junction. Based on the test results data, a constitutive equation predicting the deformation behavior of the 5083M alloy was derived. The calculated curves by the constitutive equation were compared with the measured curves by experiment and agreed well.

Application of Small Punch Test to Evaluate Tensile Properties of SA213T22 Grade Boiler Steel

2015 ◽  
Vol 830-831 ◽  
pp. 191-194
Author(s):  
M. Venkateswara Rao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tensile Properties ◽  
Test Methods ◽  
Uniaxial Tensile ◽  
Test Results ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test ◽  
Aging Phenomena

Conventional tensile test methods are used for service exposed high temperature boiler tubes to evaluate the deterioration in mechanical properties such as tensile strength, yield strength and percentage elongation. The mechanical properties are required to be evaluated periodically as the boiler components undergo material degradation due to aging phenomena. The aging phenomena occurs due to continuous exposure of tubes to high temperature & pressure steam prevailing inside the tubes and high temperature exposure to corrosive combustible gases from the external surfaces within the boiler.A recent developed new technique called small punch testing has been used to evaluate the tensile properties of SA 213T22 grade steel predominantly exists in super-heater and re-heater sections of boiler. The small punch tests have been carried out on the miniature disk shaped specimens of diameter of 8.0 mm and 0.5 mm thickness extracted from both the new and service exposed tubes. Conventional uniaxial tensile tests on standard specimens from the same tube material have also been performed for comparison. The service exposed tubes showed considerable loss in mechanical properties in both the conventional and small punch test results. Correlations of tensile properties have been obtained based on the comparative analysis of both small punch and uniaxial tensile test results. Further, the study showed that an appropriate empirical relation could be generated for new and service exposed materials between both the techniques. Conventional test methods require large quantity of material removal for test samples from in-service components whereas small punch test method needs only a miniature sample extraction. This small punch test technique could also be extended to evaluate the thicker section boiler components such as pipelines and headers in the boiler as a part of remaining life assessment study. Also this technique could be a useful tool to any metallic component where large quantity of sample removal may be difficult or may not be feasible.

scholarly journals Comparison of Mechanical and Microstructural Properties of as-Cast Al-Cu-Mg-Ag Alloys: Room Temperature vs. High Temperature

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1330
Author(s):  
Muhammad Farzik Ijaz ◽  
Mahmoud S. Soliman ◽  
Ahmed S. Alasmari ◽  
Adel T. Abbas ◽  
Faraz Hussain Hashmi
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Mechanical Testing ◽  
Tensile Testing ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Microstructural Properties ◽  
Testing Environments ◽  
Mechanical And Microstructural Properties ◽  
Mg Content

Unfolding the structure–property linkages between the mechanical performance and microstructural characteristics could be an attractive pathway to develop new single- and polycrystalline Al-based alloys to achieve ambitious high strength and fuel economy goals. A lot of polycrystalline as-cast Al-Cu-Mg-Ag alloy systems fabricated by conventional casting techniques have been reported to date. However, no one has reported a comparison of mechanical and microstructural properties that simultaneously incorporates the effects of both alloy chemistry and mechanical testing environments for the as-cast Al-Cu-Mg-Ag alloy systems. This preliminary prospective paper presents the examined experimental results of two alloys (denoted Alloy 1 and Alloy 2), with constant Cu content of ~3 wt.%, Cu/Mg ratios of 12.60 and 6.30, and a constant Ag of 0.65 wt.%, and correlates the synergistic comparison of mechanical properties at room and elevated temperatures. According to experimental results, the effect of the precipitation state and the mechanical properties showed strong dependence on the composition and testing environments for peak-aged, heat-treated specimens. In the room-temperature mechanical testing scenario, the higher Cu/Mg ratio alloy with Mg content of 0.23 wt.% (Alloy 1) possessed higher ultimate tensile strength when compared to the low Cu/Mg ratio with Mg content of 0.47 wt.% (Alloy 2). From phase constitution analysis, it is inferred that the increase in strength for Alloy 1 under room-temperature tensile testing is mainly ascribable to the small grain size and fine and uniform distribution of θ precipitates, which provided a barrier to slip by deaccelerating the dislocation movement in the room-temperature environment. Meanwhile, Alloy 2 showed significantly less degradation of mechanical strength under high-temperature tensile testing. Indeed, in most cases, low Cu/Mg ratios had a strong influence on the copious precipitation of thermally stable omega phase, which is known to be a major strengthening phase at elevated temperatures in the Al-Cu-Mg-Ag alloying system. Consequently, it is rationally suggested that in the high-temperature testing scenario, the improvement in mechanical and/or thermal stability in the case of the Alloy 2 specimen was mainly due to its compositional design.

Mechanical Properties and Oxidation Behavior of Si3N4/BN Laminated Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 1869-1872
Author(s):  
Cui Wei Li ◽  
Chang An Wang ◽  
Yong Huang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Boron Nitride ◽  
Oxidation Behavior ◽  
Elevated Temperatures ◽  
Testing Procedure ◽  
No Oxidation ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior

Laminated ceramics with high mechanical properties were fabricated in the Si3N4/BN system. The mechanical properties at elevated temperatures were tested, and the oxidation behavior during tested procedure was studied at the same time. The flexure strength of the Si3N4/BN laminated ceramics changed a little below 1000°C. The displacement-load curves appeared non-linear characteristic even at high temperature. During testing procedure at high temperature, oxidation behavior of silicon nitride and silicon carbide happened, and no oxidation product of boron nitride was found. The silicon nitride layers were oxidized to form a protective silicate scale, which prevented oxidation of the boron nitride interlayers. The stability of boron nitride was beneficial to the boron nitride interlayer to partition the silicon nitride matrix layers at high temperature.

Mechanical Properties and Microstructure of the Newly Developed Steel (Low C 18Cr-11Ni-3Cu-Mo-Nb-B-N) After Aging Treatment

2020 ◽  
Author(s):  
Nao Otaki ◽  
Tomoaki Hamaguchi ◽  
Takahiro Osuki ◽  
Yuhei Suzuki ◽  
Masaki Ueyama ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Vickers Hardness ◽  
Elevated Temperatures ◽  
Rupture Strength ◽  
Aging Treatment ◽  
High Strength ◽  
High Temperature Strength ◽  
Short Term ◽  
Rich Phase

Abstract In petroleum refinery plants, materials with high sensitization resistance are required. 347AP has particularly been developed for such applications and shows good sensitization resistance owing to its low C content. However, further improvement in high temperature strength is required for high temperature operations in complex refineries, such as delayed cokers. Recently, a new austenitic stainless steel (low C 18Cr-11Ni-3Cu-Mo-Nb-B-N, UNS No. S34752) with high sensitization resistance and high strength at elevated temperatures has been developed. In this study, the mechanical properties and microstructures of several aged specimens will be reported. By conducting several aging heat treatments in the range of 550–750 °C for 300–10,000 h on the developed steel, it was revealed that there were only few coarse precipitates that assumed sigma phase even after aging at 750 °C for 10,000 h. This indicates that the newly developed steel has superior phase stability. The developed steel drastically increased its Vickers hardness by short-term aging treatments. Through transmission electron microscopy observations, the fine precipitates of Cu-rich phase were observed dispersedly in the ruptured specimen. Therefore, the increase in Vickers hardness in short-term aging is possibly owing to the dispersed precipitation of Cu-rich phase. There was further increase in Vickers hardness owing to Z phase precipitation; however, the increment was smaller than that caused by Cu-rich phase. The newly developed alloy demonstrated excellent creep rupture strength even in the long-term tests of approximately 30,000 h, which is attributed to these precipitates.

High Temperature Mechanical Behavior of Some Advanced Ni3Al

1986 ◽  
Vol 81 ◽  
Author(s):  
S. E. Hsu ◽  
N. N. Hsu ◽  
C. H. Tong ◽  
C. Y. Ma ◽  
S. Y. Lee
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Yield Strength ◽  
Mechanical Behavior ◽  
Single Phase ◽  
Rupture Strength ◽  
Strengthening Mechanisms ◽  
High Temperature Mechanical Properties ◽  
Higher Temperature

AbstractHigh temperature mechanical properties of various Zr and Cr strengthened single phase Ni3Al are investigated, with emphasis on the ability of each element to elevate Tp, the temperature corresponding to the peak yield strength. It is observed that Zr is a very effective strengthener, more so below Tp than above it, while a combination of Cr and Zr is capable of shifting Tp to a higher temperature. The combination results in an effective improvement of the rupture strength of Ni3Al. The strengthening mechanisms of each element will be discussed in this paper.

Development of High-Strength Steel Plates for Low-Temperature Use

1988 ◽  
Vol 110 (3) ◽  
pp. 171-176
Author(s):  
Y. Nakano ◽  
Y. Saito ◽  
K. Amano ◽  
M. Koda ◽  
Y. Sannomiya ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Yield Strength ◽  
Structural Steel ◽  
Welded Joints ◽  
High Strength Steel ◽  
Control Process ◽  
Charpy Impact ◽  
High Strength ◽  
Steel Plates

This paper describes the metallurgical approaches for producing 415MPa and 460MPa yield strength offshore structural steel plates and the mechanical properties of the steel plates and their welded joints. A thermo-mechanical control process (TMCP) was adopted to manufacture YP415MPa and YP460MPa steel plates with weldability comparable to conventional YP355MPa steel plates. The Charpy impact and CTOD tests of the steel plates and their welded joints proved to be very good.

Performance of ilmenite concrete at sustained elevated temperatures

1988 ◽  
Vol 15 (5) ◽  
pp. 776-783
Author(s):  
H. S. Wilson
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Flexural Strength ◽  
Key Words ◽  
Elevated Temperatures ◽  
Cement Ratio ◽  
Nondestructive Tests ◽  
High Temperature Mechanical Properties ◽  
Curing Period

Two similar mixes were made with cement contents of about 350 kg/m3 and a water–cement ratio of 0.50. The concrete specimens, moist cured for 7 days, were cured in air for 28 and 120 days, respectively, prior to heating. The exposure temperatures were 75, 150, 300, and 450 °C. The periods of exposure at each temperature were 2, 30, and 120 days.The compressive strengths, before heating, of the specimens cured for 35 and 120 days were 41.0 and 46.2 MPa, respectively, and the flexural strengths were 4.9 and 5.8 MPa. Compared with those strengths, the strengths of the specimens heated for 30 days or more increased at 75 °C but decreased at higher temperatures. The losses increased with increase in temperature, reaching about 30% at 450 °C.The flexural strength of the concrete cured in air for 28 days was more adversely affected than was the compressive strength. The flexural and compressive strengths of the concrete cured in air for 120 days were affected to about the same degree. The longer curing period had little effect on the relative losses in compressive strength, but the longer curing period reduced the loss in flexural strength. In most applications, the loss in strength could be compensated by proportioning the mix to overdesign for strength. Key words: high-density concrete, ilmenite, aggregates, high temperature, mechanical properties, nondestructive tests.

Sign in / Sign up

Export Citation Format

Share Document