scholarly journals Effects of Cooling Rate during Quenching and Tempering Conditions on Microstructures and Mechanical Properties of Carbon Steel Flange

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4186 ◽  
Author(s):  
Haeju Jo ◽  
Moonseok Kang ◽  
Geon-Woo Park ◽  
Byung-Jun Kim ◽  
Chang Yong Choi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Cooling Rate ◽  
Charpy Impact ◽  
Hardness Test ◽  
Finite Element Method Simulation ◽  
Secondary Phases ◽  
Practical Applications ◽  
Low Temperature Toughness ◽  
Microstructures And Mechanical Properties

This study investigated the mechanical properties of steel in flanges, with the goal of obtaining high strength and high toughness. Quenching was applied alone or in combination with tempering at one of nine combinations of three temperatures TTEM and durations tTEM. Cooling rates at various flange locations during quenching were first estimated using finite element method simulation, and the three locations were selected for mechanical testing in terms of cooling rate. Microstructures of specimens were observed at each condition. Tensile test and hardness test were performed at room temperature, and a Charpy impact test was performed at −46 °C. All specimens had a multiphase microstructure composed of matrix and secondary phases, which decomposed under the various tempering conditions. Decrease in cooling rate (CR) during quenching caused reduction in hardness and strength but did not affect low-temperature toughness significantly. After tempering, hardness and strength were reduced and low-temperature toughness was increased. Microstructures and mechanical properties under the various tempering conditions and CRs during quenching were discussed. This work was based on the properties directly obtained from flanges under industrial processes and is thus expected to be useful for practical applications.

Effect of Quenching Temperature on Microstructures and Mechanical Properties of Boron-Nickel-Added Nb-Treated HSLA H-Beams

2011 ◽  
Vol 194-196 ◽  
pp. 165-168
Author(s):  
Wang Xiao ◽  
Zuo Cheng Wang ◽  
Xie Bin Wang ◽  
Xian Da Li ◽  
Jun Qing Gao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Quenching Temperature ◽  
Low Temperature Toughness ◽  
Microstructures And Mechanical Properties

To lower the fracture appearance transition temperature (FATT) of Nb-treated HSLA H-beams further, boron-nickel-added Nb-treated HSLA H-beams were tempered after they were quenched at 870, 910 and 950°C respectively. Microstructures and mechanical properties, especially low temperature toughness of the experimental steels were investigated by scanning electron microscopy (SEM), uniaxial tensile test and Charpy impact test (V-notch). The results indicate that the FATTs of quenched & tempered specimens are all below -70С and that of some specimens is even below -90°С . Tensile strength of all quenched & tempered steels and their total elongation value are above 570 MPa and 21 % respectively. It can be seen that dual-phase microstructure of ferrite and tempered martensite in steels leads to the best low temperature toughness, and carbides along grain boundaries are beneficial to low temperature toughness.

Microstructures and Mechanical Properties of AA6061-T4 Composites Containing SiC and B4C Particles Fabricated by Friction Stir Processing

2020 ◽  
Vol 12 (4) ◽  
pp. 531-537 ◽  
Author(s):  
Hyun-Joon Park ◽  
Byung-Wook Ahn ◽  
Jae-Ha Kim ◽  
Jong-Gun Lee ◽  
Seung-Boo Jung
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Friction Stir Processing ◽  
Vickers Hardness ◽  
Charpy Impact ◽  
Hardness Test ◽  
Charpy Impact Test ◽  
Ceramic Particles ◽  
Friction Stir ◽  
Microstructures And Mechanical Properties

AA6061-T4 composites containing SiC and B4C particles were fabricated by friction stir processing (FSP) with an SKD11 tool. The microstructures and mechanical properties of the composites were investigated with various test methods. With the inclusion of ceramic particles, refined grains in the stir zone (SZ) were observed using a scanning electron microscope (SEM) and tunneling electron microscope (TEM). Because the ceramic particles facilitated grain refinement in the SZ via the pinning effect, the SZ with the particles had a much smaller grain size than the SZ without the particles. Vickers hardness test, tensile test and Charpy impact test were conducted to evaluate the mechanical properties. Mechanical properties of the SZ with the ceramic particles were improved relative to those of the SZ without the particles. Vickers hardness (from 50 to 90 HV), tensile strength (from 117 to 253 MPa) and Charpy impact absorbed energy (from 4.2 to 5.6 J) of the SZ increased with the addition of ceramic particles.

Mechanical Properties and Microstructure of LR Grade a Thick Plate Welded by Double Side Gas Metal Arc Welding

2016 ◽  
Vol 851 ◽  
pp. 168-172
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
Tegar Rileh Argihono ◽  
Ryan Sutrisno
Keyword(s):  
Mechanical Properties ◽  
Gas Flow ◽  
Gas Metal Arc Welding ◽  
Charpy Impact ◽  
Hardness Test ◽  
Charpy Impact Test ◽  
Optical Microscope ◽  
Steel Plates ◽  
Weld Metals ◽  
Metal Arc Welding

Mechanical and microstructure of double side weld with various angle groove was studied in this research. LR Gr A steel plates (12 mm thickness) were welded using GMAW with corresponding 180 A, 23 V, and 20 l/min respectively with current, voltage, and gas flow. Shielding gas and filler metals used are argon and ER 70S-6. The angle groove that used were 20⁰, 40⁰ and 60⁰. The measured of mechanical properties with regard to hardness, toughness and strength using, Vickers hardness test, Charpy impact test and tensile test respectively The microstructure examined with optical microscope. The results show that the highest hardness values found in welds with groove angle 40ͦ. The transition temperatures of weld metals are at temperatures between -20°C to 0°C. Weld metals with all variations of the groove angle has a value of less than 0.1 mmpy. Microstructure of base metals and HAZ were ferrite and pearlite. While the microstructure of weld metals are accicular ferrite, grain boundary ferrite and Widmanstatten ferrite.

scholarly journals Effects of Silicon Content and Tempering Temperature on the Microstructural Evolution and Mechanical Properties of HT-9 Steels

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 972 ◽  
Author(s):  
Junkai Liu ◽  
Wenbo Liu ◽  
Zhe Hao ◽  
Tiantian Shi ◽  
Long Kang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Microstructural Evolution ◽  
Charpy Impact ◽  
Hardness Test ◽  
Mechanical Tests ◽  
Fourth Generation ◽  
Martensitic Steels ◽  
Microscopic Mechanism ◽  
Tempering Temperature

Two kinds of experimental ferritic/martensitic steels (HT-9) with different Si contents were designed for the fourth-generation advanced nuclear reactor cladding material. The effects of Si content and tempering temperature on microstructural evolution and mechanical properties of these HT-9 steel were studied. The microstructure of experimental steels after quenching and tempering were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM); the mechanical properties were investigated by means of tensile test, Charpy impact test, and hardness test. The microscopic mechanism of how the microstructural evolution influences mechanical properties was also discussed. Both XRD and TEM results showed that no residual austenite was detected after heat treatment. The results of mechanical tests showed that the yield strength, tensile strength, and plasticity of the experimental steels with 0.42% (% in mass) Si are higher than that with 0.19% Si, whereas hardness and toughness did not change much; when tempered at 760 °C, the strength and hardness of the experimental steels decreased slightly compared with those tempered at 710 °C, whereas plasticity and toughness increased. Further analysis showed that after quenching at 1050 °C for 1 h and tempering at 760 °C for 1.5 h, the comprehensive mechanical properties of the 0.42% Si experimental steel are the best compared with other experimental steels.

Influence of Heat Treatment on the Microstructures and Mechanical Properties of K465 Superalloy

2016 ◽  
Vol 849 ◽  
pp. 570-579
Author(s):  
Qiang Huang ◽  
Jin Xia Song ◽  
Qing Li ◽  
Wei Peng Ren ◽  
Xin Guang Guan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Room Temperature ◽  
Rupture Life ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M6C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.

Effects of Electromagnetic Stirring Frequency on the Microstructure and Mechanical Properties of Al-7Si-0.42 Mg-0.1Cu Alloy by Semi-Solid Processing

2017 ◽  
Vol 898 ◽  
pp. 104-110 ◽  
Author(s):  
Peng Qi ◽  
Bo Long Li ◽  
Wen Jian Lv ◽  
Tong Bo Wang ◽  
Zuo Ren Nie
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Low Temperature ◽  
Fracture Morphology ◽  
Electromagnetic Stirring ◽  
Spherical Morphology ◽  
Microstructure And Mechanical Properties ◽  
Microstructures And Mechanical Properties ◽  
Semi Solid ◽  
Dendritic Structures

The effect of the different electromagnetic stirring frequency after low temperature pouring on microstructures and mechanical properties of Al-7Si-0.42 Mg-0.1Cu alloys was studied. It was found that the primary α-Al becomes smaller and tended to be spherical morphology, and the particles were uniformly distributed after electromagnetic stirring. The tensile strength of alloys improved gradually from 193.02 MPa to 212.54 MPa, and the elongation increased from 3.73% to 6.67% when the stirring frequency was 10 Hz. From the fracture morphology, the fracture for alloy stirred at frequency of 10 Hz showed more dimples than that without stirring. When the stirring frequency increased to 15 Hz, the microstructures of primary α-Al appeared to be dendritic structures, and the grains became coarse. As a result, the 10 Hz was the best electromagnetic stirring frequency.

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.

Effect of Severe Plastic Deformation at Ambient Temperature on Microstructures and Mechanical Properties of Aluminum Alloy 2519

2013 ◽  
Vol 745-746 ◽  
pp. 298-302
Author(s):  
Ying Liu ◽  
Ruo Lin Cheng ◽  
Jing Tao Wang ◽  
He Zhang ◽  
Xin Ming Zhang
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Severe Plastic Deformation ◽  
Cold Rolling ◽  
Ambient Temperature ◽  
Hardness Test ◽  
Equal Channel Angular Processing ◽  
Microstructures And Mechanical Properties

The effect of severe plastic deformation at ambient temperature on microstructures and mechanical properties of aluminum alloy 2519 was investigated by means of tensile test, micro-hardness test, optical microscopy and scanning electron microscopy. The results showed that tensile strength of as-queched 2519 alloy was greatly enhanced to nearly 550MPa (ultimate tensile strength, UTS) and 520MPa (yield strength, YS) by severe cold rolling or equal channel angular processing (ECAP) while the elongation decreased to 5%. The 2519 alloy could obtain quite well mechanical properties as much as 80 % and 12 passes cold rolling deformation. This indicated that pre-deformation by ECAP is effective in improving the mechanical properties of 2519 alloy by grain refinement, strain aging and high density dislocations.

Study on Microstructures and Properties of 22Mn2SiVBS Steel on Different Cooling Rate

2012 ◽  
Vol 535-537 ◽  
pp. 768-771
Author(s):  
Min Wang ◽  
Hong Xin ◽  
Shu Lan Guo
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Fine Grain ◽  
Proeutectoid Ferrite ◽  
Microstructures And Mechanical Properties

Abstract:The microstructures and mechanical properties of 22Mn2SiVBS steel after austenitizing at 1280°C and then cooling in air and piled up after rolled were studied in this paper .the results show that when 22Mn2SiVBS steel cooling in air it can obtain the fine grain granular bainte and remain austenite,and piled up after rolled it can obtain granular bainte and proeutectoid ferrite. After heat treatment the strength and hardness is higher than the sample piled up after rolled, but the toughness is lower.

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