Experimental Investigation of Post-Fire Mechanical Properties of Q345R Steel

2015 ◽  
Author(s):  
Shanshan Shao ◽  
Guodong Jia ◽  
Luowei Cao ◽  
Chenyang Du
Keyword(s):  
Mechanical Properties ◽  
Heat Exposure ◽  
Tensile Tests ◽  
Pressure Vessels ◽  
Metallographic Analysis ◽  
Fire Exposure ◽  
Hardness Testing ◽  
Fire Event ◽  
Metallographic Examination ◽  
Different Temperatures

The degeneration of mechanical properties is one of the main concerns in assessment of fire damaged pressure vessels. This study investigates the influence of fire exposure on mechanical properties of Q345R steel which is widely used for pressure vessels in China. Heat treatment with different temperatures and holding times was conducted to simulate various heat exposure conditions in fire event. Hardness testing, metallographic analysis and tensile tests were carried out to investigate the effects of fire exposure temperature and duration. The experimental results indicate that the inflection temperature for mechanical property degeneration of Q345R steel is 700 °C. The decline of hardness, yield and tensile strengths due to spheroidization become more obvious with increasing heat exposure duration. A linear correlation is indicated by fitting the tensile strength and hardness. For the assessment of fire damaged component, the mechanical properties of Q345R steel at room temperature can be determined combining on-situ field metallographic examination and hardness testing with.

scholarly journals Effects of Different Solid Solution Temperatures on Microstructure and Mechanical Properties of the AA7075 Alloy After T6 Heat Treatment

2019 ◽  
Vol 38 (2019) ◽  
pp. 892-896 ◽  
Author(s):  
Süleyman Tekeli ◽  
Ijlal Simsek ◽  
Dogan Simsek ◽  
Dursun Ozyurek
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Tensile Tests ◽  
Solution Temperature ◽  
T6 Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
Different Temperatures

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.

scholarly journals Performance of Thermo-Mechanically Processed AA7075 Alloy at Elevated Temperatures—From Microstructure to Mechanical Properties

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 884 ◽  
Author(s):  
Seyed Vahid Sajadifar ◽  
Emad Scharifi ◽  
Ursula Weidig ◽  
Kurt Steinhoff ◽  
Thomas Niendorf
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Forming Process ◽  
Softening Mechanism ◽  
Rate Dependent ◽  
Heat Treated ◽  
Different Temperatures ◽  
Die Forming

This study focuses on the high temperature characteristics of thermo-mechanically processed AA7075 alloy. An integrated die forming process that combines solution heat treatment and hot forming at different temperatures was employed to process the AA7075 alloy. Low die temperature resulted in the fabrication of parts with higher strength, similar to that of T6 condition, while forming this alloy in the hot die led to the fabrication of more ductile parts. Isothermal uniaxial tensile tests in the temperature range of 200–400 °C and at strain rates ranging from 0.001–0.1 s−1 were performed on the as-received material, and on both the solution heat-treated and the thermo-mechanically processed parts to explore the impacts of deformation parameters on the mechanical behavior at elevated temperatures. Flow stress levels of AA7075 alloy in all processing states were shown to be strongly temperature- and strain-rate dependent. Results imply that thermo-mechanical parameters are very influential on the mechanical properties of the AA7075 alloy formed at elevated temperatures. Microstructural studies were conducted by utilizing optical microscopy and a scanning electron microscope to reveal the dominant softening mechanism and the level of grain growth at elevated temperatures.

scholarly journals Mechanical Properties of Antarctic Deep-Core Ice

1979 ◽  
Vol 24 (90) ◽  
pp. 487-489 ◽  
Author(s):  
H. Shoji ◽  
A. Higashi
Keyword(s):  
Mechanical Properties ◽  
Ice Sheet ◽  
Vertical Direction ◽  
Tensile Tests ◽  
Strain Rates ◽  
Stress Strain ◽  
The Core ◽  
Different Temperatures

AbstractTensile tests were carried out with core-ice samples obtained from various depths at Byrd Station, Antarctica in 1968, Specimens for the tests were so prepared as to have their long axes parallel (L specimen), perpendicular (T specimen), and inclined at 450(I specimen) with respect to the axis of the core, or to the vertical direction of the ice sheet. Stress-strain relations for many specimens were obtained from tensile tests with different strain-rates and also at different temperatures between —10 and — 20°C.

Microstructure and Mechanical Properties of X80 Induction Heating Bends

2013 ◽  
Vol 762 ◽  
pp. 158-164
Author(s):  
Liu Qing Yang ◽  
Yu Liu ◽  
Bin Feng ◽  
Yu Ran Fan ◽  
Deng Zun Yao
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Induction Heating ◽  
Heating Temperature ◽  
Tensile Tests ◽  
Granular Bainite ◽  
Metallographic Analysis ◽  
Good Strength ◽  
Microstructure And Mechanical Properties ◽  
Strength And Toughness

By using physical thermal simulation technology, combined with metallographic analysis, tensile tests, impact and hardness tests, effects of heating temperature and cooling speed on microstructure and mechanical properties of X80 induction heating bends were investigated. The results show that as the heating temperature rises, TS of X80 induction heating bends increases gradually. However, when the heating temperature rises above 1100°C, plasticity and toughness of the bends begin to decrease, and grain growth tends to be obvious. When the heating temperature is 1050°C, X80 induction heating bends have a good strength and toughness. As the cooling rate increases, strength and toughness of X80 bends are improved considerably. In the cooling rate range between 20°C/s and 30°C/s, the microstructure of X80 bends is mainly composed of polygonal ferrite and granular bainite. Due to the very high dislocation density inside granular bainite and the fine and dispersed M-A constituents, X80 induction heating bends have a very good strength and toughness.

scholarly journals Excellent mechanical properties of taenite in meteoric iron

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shohei Ueki ◽  
Yoji Mine ◽  
Kazuki Takashima
Keyword(s):  
Mechanical Properties ◽  
Nitrogen Solubility ◽  
High Strength ◽  
Tensile Tests ◽  
Metallographic Analysis ◽  
Advanced High Strength Steel ◽  
Analysis Techniques ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Strength And Ductility

AbstractMeteoric iron is the metal that humans first obtained and used in the earliest stage of metal culture. Advances in metallographic analysis techniques have revealed that meteoric iron largely comprises kamacite, taenite, and cohenite, which correspond to ferrite, austenite, and cementite in artificial steel, respectively. Although the mechanical properties of meteoric irons were measured previously to understand their origin and history, the genuine mechanical properties of meteoric iron remain unknown because of its complex microstructure and the pre-existing cracks in cohenite. Using micro-tensile tests to analyse the single-crystalline constituents of the Canyon Diablo meteorite, herein, we show that the taenite matrix exhibits excellent balance between yield strength and ductility superior to that of the kamacite matrix. We found that taenite is rich in nitrogen despite containing a large amount of nickel, which decreases the nitrogen solubility, suggesting that solid-solution strengthening via nitrogen is highly effective for the Fe–Ni system. Our findings not only provide insights for developing advanced high-strength steel but also help understand the mysterious relationship between nitrogen and nickel contents in steel. Like ancient peoples believed that meteoric iron was a gift from the heavens, the findings herein imply that this thought continues even now.

Study on Mechanical Properties at High Temperatures and Microstructure of Mg-12Gd-3Y-0.5Zr Magnesium Alloy

2014 ◽  
Vol 997 ◽  
pp. 618-623 ◽  
Author(s):  
Tian Dong Cao ◽  
Xiao Ming Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
High Temperatures ◽  
Tensile Tests ◽  
Strengthening Mechanism ◽  
Heat Treated ◽  
Different Temperatures ◽  
Solution Strengthening ◽  
Tension Compression Asymmetry

In this paper, tensile tests were carried out on the as-rolled and heat-treated Mg-12Gd-3Y-0.5Zr magnesium alloy at different temperatures. Tendency of tensile strength vs temperature was investigated and strengthening mechanism was discussed. It shows that both as-rolled and heat-treated Mg-12Gd-3Y-0.5Zr magnesium alloy have good mechanical properties at high temperatures. The reason why they have poor tension-compression asymmetry was discussed by their texture analysis. It is indicated that solution strengthening and precipitation strengthening were main strengthening mechanisam, and RE additons improve their thermal stability which lead to their high tensile strength at high temperatures.

scholarly journals Mechanical properties of metal and polymeric viscoelastic materials and their applications

2022 ◽  
Vol 2152 (1) ◽  
pp. 012055
Author(s):  
Kai Kang
Keyword(s):  
Mechanical Properties ◽  
Polymeric Materials ◽  
Tensile Tests ◽  
Viscoelastic Materials ◽  
Loading Rates ◽  
Linear Elastic ◽  
Axial Tensile ◽  
Different Temperatures ◽  
Plastic Parts ◽  
Insight Into

Abstract Nowadays, With the wide application of metals and polymeric materials, how to describe the property of Viscoelastic material and how to apply them in engineering has become more and more critical. Due to the lack of insight into the mechanical properties of viscoelastic materials, many scholars have done a lot of experiments in studying the behavior of viscoelastic materials. Axial tensile tests were conducted on specimens to derive different mechanical behaviors of metals, polymers, and other materials at different temperatures and loading rates. Metal can generally be divided into elastic and plastic parts, while polymeric materials have the phases of the linear elastic region, drawing region, and oriented molecular strength region. This paper also shows a test conducted by Argon, Ali S., and M. I. Bessonov of four different kinds of polymers at different circumstances of temperature. After that, the paper shows the application of viscoelastic materials as CLD in damping and some engineering problems caused by the mechanical properties of viscoelastic materials. Currently, research on viscoelasticity should mainly focus on the application of Finite Element Methods and the acquisition of more experimental data to establish a complete theoretical system.

Influence of Extrusion Temperature on Microstructures and Properties of Cu-17Ni-3Al-X Alloy

2013 ◽  
Vol 749 ◽  
pp. 105-111
Author(s):  
Wei Yan ◽  
Yuan Hui Weng ◽  
Zong Qiang Luo ◽  
Wei Wen Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Brinell Hardness ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Different Temperatures ◽  
Electronic Microscope

The microstructures and mechanical properties of the Cu-17Ni-3Al-X alloy extruded at different temperatures were investigated by hardness and tensile tests, optical microscope and scanning electronic microscope. The experimental results showed that dynamic re-crystallization occured during the hot extrusion at 1000 . The grain size of the extruded alloy was significantly refined and the mechanical properties increased remarkably compared to the as-cast alloy. The alloy extruded at 1075 exhibited good mechanical properties with tensile strength of 994 MPa, Brinell hardness of 296 and elongation of 8.0%, which are 30%, 9% and 285% higher than that of the as-cast alloy.

Experimental Investigation of Mechanical Properties and Forming Capabilities in Thin Magnesium Sheet at Elevated Temperature

2013 ◽  
Vol 315 ◽  
pp. 527-530
Author(s):  
M. Waseem Soomro ◽  
M. Akhtar ◽  
R. Khan ◽  
S. Altaf
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Strain Diagram ◽  
Drawing Ratio ◽  
Punch Force ◽  
Blank Holder ◽  
Different Temperatures

This paper investigates the mechanical properties and forming capabilities of magnesium ZE10. Mechanical properties are observed by stress strain diagram. Three types of the samples are used which are machined from thin sheets of 0.8mm thickness in 00, 450, 900 of the rolling direction (RD). The samples are then tested at different temperatures varying from room temperature (RT) to 400°C. The factors that are considered in tensile tests are Youngs modulus, Yield strength, Ultimate tensile strength and fracture strain. The later part of this paper is devoted to deep drawing tests in which specimen are drawn from room temperature to 250°C. In these tests variation of Limit Drawing Ratio (LDR) is investigated at different temperatures. The other parameters observed are drawing depth, punch force, blank holder force and their variation from room temperature to elevated temperature.

Fitness for Service Assessment of a Propylene Heat Exchanger Subjected to Fire Damage

2020 ◽  
Author(s):  
Shanshan Shao ◽  
Luowei Cao ◽  
Guodong Jia ◽  
Zhiyuan Han
Keyword(s):  
Heat Exchanger ◽  
Construction Material ◽  
Heat Exposure ◽  
The Finite Element Method ◽  
Hardness Testing ◽  
Fire Event ◽  
Exposure Temperature ◽  
Magnetic Particle Testing ◽  
Fire Accident

Abstract Pressurized equipments maybe deform partially or wholly, and the mechanical properties of the construction material would be degraded due to a fire event. Fitness for service assessment can help to minimize reconstruction costs and allow safe resumption of unit operation as fast as possible. A propylene heat exchanger was exposed to overheating for about 3 hours due to a fire accident five or six meters far away. A fitness for service assessment was conducted according to API 579-1/ASME FFS-1. The material of the propylene heat exchanger is 09MnNiDR. The possible damage was examined by dimensional checks, hardness testing, in-situ field metallography, ultrasonic testing and magnetic particle testing. The heat exposure temperature of the propylene heat exchanger during the fire accident was estimated through the comparison between the results of in-situ field metallography examination and heat exposure simulation experiments. The heat exposure zones were identified based on the results of visual inspection and conjectural heat exposure temperature. The level 2 assessment was adopted to evaluate the heat exposure zones of V and VI. The approximate ultimate tensile strengths for the shell and the eastern head were converted from the hardness testing results. The caculated MAWP of the shell side is higher than the design pressure of the heat exchanger. The finite element method was adopted to evaluate the influence of the bulge in the upper part of the shell. The analytical results showed that the bulge had no significant effect on the operation of the heat exchanger before next inspection.

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