Tensile strength/yield strength (TS/YS) ratios of high-strength steel (HSS) reinforcing bars

Abstract The paper analyzes the influence of different heat treatment processes on the mechanical properties of low-alloy high-strength steel denoted by Polish Standard (PN) as 10MnVNb6. One of the findings is that, after aging, the mechanical properties of rolled steel are high: the yield strength may reach > 600 MPa, and the ultimate tensile strength is > 700 MPa. These properties are largely dependent on the grain size and dispersion of the strengthening phase in the ferrite matrix. Aging applied after hot rolling contributes to a considerable rise in the yield strength and ultimate tensile strength. The process of normalization causes a decrease in the average grain size and coalescence (reduction of dispersion) of the strengthening phase. When 10MnVNb6 steel was aged after normalization, there was not a complete recovery in its strength properties.

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The Influence of Hot-Dip Galvanizing on the Mechanical Properties of High-Strength Steels

Materials ◽

10.3390/ma14185219 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5219

Author(s):

Milan Šmak ◽

Jaroslav Kubíček ◽

Jiří Kala ◽

Kamil Podaný ◽

Jan Vaněrek

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Chemical Composition ◽

Yield Strength ◽

High Strength Steel ◽

High Strength Steels ◽

High Strength ◽

Steel Members ◽

Different Types ◽

Standard Quality

Modern high-strength steels achieve their strength exclusively through the manufacturing process, as the chemical composition of these steels is very similar to the composition of standard-quality steels. Typically, hot-dip galvanizing is used to form a protective zinc layer on the steel parts of structures; nonetheless, the material is exposed to high temperatures during the process. With high-strength steels, this can lead to deterioration of the mechanical properties. This study aims to experimentally examine and evaluate the extent of deterioration of the mechanical properties of high-strength-steel members. The effect was studied on specimens made of three different types of steel with the yield strength ranging from 460 to 1250 MPa. For each type of steel, selected mechanical properties—yield strength, tensile strength, and hardness—were determined on specimens with and without hot-dip galvanization, and the obtained results were mutually compared. Our study shows a significant impact of the hot-dip galvanization process on the mechanical properties of some high-strength steels. With the studied types of steel, the yield strength decreased by up to 18%, the tensile strength by up to 13%, and the hardness by up to 55%.

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Application of 3D digital image correlation for the measurement of the tensile mechanical properties of high-strength steel

Materials Testing ◽

10.1515/mt-2020-0044 ◽

2021 ◽

Vol 63 (4) ◽

pp. 303-310

Author(s):

Feipeng Zhu ◽

Xiaoxia Gu ◽

Pengxiang Bai ◽

Dong Lei

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Digital Image Correlation ◽

Yield Strength ◽

Digital Image ◽

High Strength Steel ◽

High Strength ◽

Experimental Results ◽

Image Correlation ◽

3D Digital Image Correlation

Abstract High-strength steel plays an important role in engineering fields such as infrastructure. For this reason, an accurate determination of its mechanical properties is of critical importance. Considering the inconvenience of conventional mechanical extensometers for the deformation measurement of small-scale specimens, 3D digital image correlation (3D-DIC) was used to measure the deformation of Grade 8.8 bolts and Q690 high-strength steel specimens by means of a uniaxial tensile test, and in this way, stress–strain curves, elastic modulus, yield strength, tensile strength, percentage elongation after fracture, and percentage reduction of area were obtained. Experimental results show that Grade 8.8 bolts and Q690 steel result in higher yield strength and tensile strength than common steel. Moreover, owing to the phenomenon that stress remains constant with strain increase in the yielding stage, the evolution process from elastic deformation to plastic deformation of the specimens during the yielding stage could be studied. Experimental results show that the axial strain of Grade 8.8 bolts increases from 0.3 to 1 % during the yielding stage and for Q690 specimens the corresponding strain increases from 0.4 to 1.8 %.

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High-Strength Steel Door-Beam Design and Digital Simulation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1063.264 ◽

2014 ◽

Vol 1063 ◽

pp. 264-267

Author(s):

Zhong De Shan ◽

Qin Tai Yan ◽

Chao Jiang ◽

Wen Juan Rong

Keyword(s):

Tensile Strength ◽

Yield Strength ◽

High Strength Steel ◽

Digital Simulation ◽

High Strength ◽

Uniform Thickness ◽

Beam Design ◽

G1 Continuity ◽

Classical Part

Due to the yield strength σs, tensile strength σb of high-strength steel is much higher than original one, it is applied in making auto’s structure parts to improve the security of passengers and reduce the weight of auto. To make the production of the cold-stamp parts easier, the paper analyzed the structure of a classical part, door-beam, and found that the surface of the part should be G1 continuity at least, rather than G0 continuity. The G1 continuity part has more uniform thickness, less inner strain, and more safety from cracking.

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Thermo-Mechanically Controlled Processed Ultrahigh Strength Steels

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.685 ◽

2014 ◽

Vol 783-786 ◽

pp. 685-691

Author(s):

Subrata Chatterjee ◽

S.K. Ghosh ◽

P.S. Bandyopadhyay

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Yield Strength ◽

High Strength Steel ◽

Bainitic Ferrite ◽

High Strength ◽

Bearing Steel ◽

Pressure Vessels ◽

Low Carbon ◽

Ultra High Strength Steel

A low-carbon, titanium and niobium (Ti-Nb) bearing and a low-carbon titanium, niobium and copper (Ti-Nb-Cu) bearing ultra high strength steel have been thermo-mechanically processed on a laboratory scale unit. Evolution of microstructure and mechanical properties of the above air cooled steels have been studied at different finish rolling temperatures (FRTs). Microstructural characterization reveals largely a mixture of granular bainite and bainitic ferrite along with the precipitation of microalloying carbide/carbonitride particles and/or Cu-rich precipitates. (Ti-Nb) bearing steel yields higher yield strength (1114-1143 MPa) along with higher tensile strength (1591-1688 MPa) and moderate ductility (12-13%) as compared to (Ti-Nb-Cu) bearing steel having yield strength (934-996 MPa) combined with tensile strength (1434-1464 MPa) and similar ductility (13%) for the selected range of 850-750°C FRT. Due to higher strength-ductility combinations, these present investigated steels can be regarded as the replacement material for ballistic applications as well as other sectors like defense, pipeline, cars, pressure vessels, ships, offshore platforms, aircraft undercarriages and rocket motor casings etc. Key words: Thermo-mechanical controlled processing, ultra high strength steel, microstructure, mechanical properties.

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Phase Transformation Rule, Microstructure and Properties of JG590 High Strength Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.29 ◽

2007 ◽

Vol 561-565 ◽

pp. 29-32

Author(s):

Yong Feng ◽

Wei Hua Sun

Keyword(s):

Tensile Strength ◽

Phase Transformation ◽

Yield Strength ◽

Cooling Rate ◽

High Strength Steel ◽

High Strength ◽

Steel Plates ◽

Transformation Rule ◽

Cooling Rates ◽

Iron And Steel

The phase transformation rule, microstructures and properties of JG590 high strength steel produced in Jinan Iron and Steel Co. ltd. have been investigated in this paper. When the chemical composition of steel are given, the cooling rates after finished rolling affect on the properties of steel greatly. The yield strength and tensile strength increasing, the elongation and reduction of area decreasing as increasing of cooling rates after rolling. The main cause is due to appearance and increasing of Bainite and Martensite other than Ferrite and Pearlite in room temperature. The finished rolling temperature have distinct effects upon the mechanical properties of steel plates. Finished rolling at different temperature with the 0.5°C/s cooling rate, the tensile strength vary in 599-698MPa, the yield strength changed from 412 MPa to 536MPa. The elongation is between 30.4-40.5%. But when finished rolling at different temperature with the 2.0°C/s cooling rate, the tensile strength vary in 747-784MPa, the yield strength changed from 441 MPa to 601MPa. The strength index can both meet the requirements of employ. But the elongation is only 18.7-24.5%. This is related with production of lots of Bainite microstructure more than 2°C/s cooling rate. In the procedure of manufacture of JG590 high steel, the quickly cooling rate should be avoided to keep suitable microstructure and good elongation and toughness.

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

Applied Sciences ◽

10.3390/app112411833 ◽

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.

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CRUCIBLE D6

Alloy Digest ◽

10.31399/asm.ad.sa0129 ◽

1962 ◽

Vol 11 (5) ◽

Keyword(s):

Fracture Toughness ◽

Tensile Strength ◽

Low Temperature ◽

High Strength Steel ◽

High Strength ◽

Heat Treating ◽

Steel Company ◽

Temperature Performance ◽

Ultra High Strength Steel ◽

Crucible Steel

Abstract Crucible D6 is a low alloy ultra-high strength steel developed for aircraft-missile applications and primarily designed for use in the 260,000-290,000 psi tensile strength range. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on low temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-129. Producer or source: Crucible Steel Company of America.

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Study on the Bending and Joint Performances of Reinforced Concrete Beams Using High-Strength Rebars

Sustainability ◽

10.3390/su13063482 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3482

Author(s):

Seoungho Cho ◽

Myungkwan Lim ◽

Changhee Lee

Keyword(s):

Yield Strength ◽

High Strength ◽

Reinforced Concrete Beams ◽

High Yield ◽

Performance Tests ◽

Reinforcing Bars ◽

Joint Performance ◽

Lap Splice ◽

Reinforcing Bar ◽

Nominal Strength

High-strength reinforcing bars have high yield strengths. It is possible to reduce the number of reinforcing bars placed in a building. Accordingly, as the amount of reinforcement decreases, the spacing of reinforcing bars increases, workability improves, and the construction period shortens. To evaluate the structural performance of high-strength reinforcing bars and the joint performance of high-strength threaded reinforcing bars, flexural performance tests were performed in this study on 12 beam members with the compressive strength of concrete, the yield strength of the tensile reinforcing bars, and the tensile reinforcing bar ratio as variables. The yield strengths of the tensile reinforcement and joint methods were used as variables, and joint performance tests were performed for six beam members. Based on this study, the foundation for using high-strength reinforcing bars with a design standard yield strength equal to 600 MPa was established. Accordingly, mechanical joints of high-strength threaded reinforcing bars (600 and 670 MPa) can be used. All six specimens were destroyed under more than the expected nominal strength. Lap splice caused brittle fractures because it was not reinforced in stirrup. Increases of 21% to 47% in the loads of specimens using a coupler and a lock nut were observed. Shape yield represents destruction—a section must ensure sufficient ductility after yielding. Therefore, a coupler and lock nut are effective.

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