The Influence of Controlled Rolling and Cooling on Microstructure and Mechanical Properties of Marine Steel

2020 ◽  
Vol 1003 ◽  
pp. 47-53
Author(s):  
Hao Xu Wang ◽  
Zhuang Li ◽  
Yi Qin Cai ◽  
Wen Hao Cai ◽  
Li Zhang ◽  
...  
Keyword(s):  
Impact Energy ◽  
Controlled Rolling ◽  
Granular Bainite ◽  
Longitudinal Impact ◽  
Lateral Impact ◽  
Impact Performance ◽  
Fine Grain ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness ◽  
Better Than

A microstructure consisted of granular bainite, upper bainite, acicular ferrite, polygonal ferrite, and a little of pearlite was obtained by controlling rolling and cooling in marine steel. The grain size of the two steels was refined to 5-9 μm. The size of the MA island was about 3-6 μm. Both steels had higher tensile strength, yield strength, elongation and hardness, and the performance of steel B was better than that of steel A. Both steels exhibited large and deep dimples at -80 °C impact fracture. The longitudinal impact energy of the specimens was above 250J, and the steel B even exceeded 300J. Its longitudinal impact performance was better than lateral impact performance. Both steels had achieved good performance due to fine grain strengthening, MA island strengthening, precipitation strengthening and dislocation strengthening caused by controlled rolling and cooling. The alloying element nickel effectively improved the low temperature impact toughness of the experimental steel. Excellent impact energy of both steels was attributed to higher texture strength for RD specimens.

Study on the Weldability of S32205 Steel under Different Welding Processes

2011 ◽  
Vol 239-242 ◽  
pp. 793-796 ◽  
Author(s):  
Li Yang ◽  
Na Zhang
Keyword(s):  
Corrosion Resistance ◽  
Mechanical Characteristics ◽  
Weld Zone ◽  
Metallic Phase ◽  
Weak Zone ◽  
Impact Performance ◽  
The Third ◽  
Temperature Impact ◽  
Welding Processes ◽  
Better Than

The effect of different welding methods on joints’ microstructure and properties of A240-S32205 duplex stainless steel was studied. The result showed all joints using GTAW and SMAW can attain good phase ratio and corrosion resistance. But the comprehensive mechanical characteristics of joint using GTAW was better than that of SMAW joint with acid electrode. Besides, the low temperature impact performance was not ideal in joints manual welded with acid electrode. The HAZ was identified as a weak zone where the corrosion resistance was the worst and in which the third detrimental metallic phase was more liable to emerge than in weld zone.

Impact Performance of ZnAl27Cu2.5MgMn Alloy from Room Temperature to 250°C

2014 ◽  
Vol 915-916 ◽  
pp. 597-601
Author(s):  
Ming Long Kang ◽  
Wu Hu ◽  
Jian Min Zeng
Keyword(s):  
Impact Toughness ◽  
Impact Energy ◽  
Room Temperature ◽  
Impact Testing ◽  
Impact Behavior ◽  
Impact Performance ◽  
Temperature Impact ◽  
Spectrum Curve ◽  
The Impact ◽  
Pendulum Impact

The impact performance of ZnAl27Cu2.5MgMn alloy from room Temperature to 2500 °C has been investigated by pendulum impact testing. The surface morphology of impact fracture is observed by scan electron microscope (SEM). The results indicate that impact energy of the alloy decreases as the temperature increases when the temperatures are lower than 100°C. Between 100°C and 200°C, impact energy increases as the temperature increases. And when the temperature exceeds 250°C, impact energy decreases dramatically. Impact energy gets to the maximum at room temperature. Impact behavior of the alloy can be evaluated by the width of impact spectrum curve. The wider the peak of impact spectrum curve, the higher the impact toughness. Whereas impact toughness is worse if peak is narrow.

scholarly journals Microstructure and Charpy Impact Toughness of a 2.25Cr-1Mo-0.25V Steel Weld Metal

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3013 ◽  
Author(s):  
Kefan Wu ◽  
Yingjie Yan ◽  
Rui Cao ◽  
Xinyu Li ◽  
Yong Jiang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Impact Toughness ◽  
Weld Metal ◽  
Power Plants ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Granular Bainite ◽  
Confocal Laser ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness

The demand for heat-resistant steel has increased owing to its utility in numerous devices that must withstand high steam pressures and high temperatures, such as turbine rotors and blades in ultra-supercritical power plants. It is inevitable to join heat-resistance steel part by welding method, so it is important to maintain the toughness of the weld metals. In this study, the microstructure, low-temperature impact toughness, and fracture surface of as-welded and post-weld heat treatment (PWHT) of 2.25Cr-1Mo-0.25V weld metal were investigated. The microstructures of the as-welded and PWHT specimens are granular bainite and ferrite, respectively. This work revealed the relationship between effective microstructure nearby crack initiation origin and low temperature impact toughness for both the as-welded and PWHT specimens. The evolution of the microstructure and prior austenite was then investigated using confocal laser scanning microscopy (CLSM) to observe the formation of coarse ferrite grain structures. A suggestion for enhancing the low-temperature toughness was provided based on the effect of adjusting Mn content and forming acicular ferrite.

Microstructure and Properties of High Performance Steels by Controlled Rolling

2013 ◽  
Vol 459 ◽  
pp. 87-90
Author(s):  
Yue Bin Zhu ◽  
Xue Min Wang
Keyword(s):  
Low Temperature ◽  
Impact Toughness ◽  
High Performance ◽  
Uniform Elongation ◽  
Controlled Rolling ◽  
Similar Performance ◽  
Performance Requirements ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness ◽  
Quenched And Tempered Steel

High performancesteels (HPS) require low yield ratio, high uniform elongation and high low temperature impact toughness in addition to higher strength. In this paper,experimental steelswere produced by controlled rolling and tempering to meet high performance requirements. Itwasconcluded that experimental steels by controlled rolling and tempering had similar performance with quenched and tempered steel (QT).

Effect of Trace Boron on Low Temperature Impact Toughness of Hot-Rolled Nb-Added HSLA H-Beams

2012 ◽  
Vol 174-177 ◽  
pp. 1030-1033 ◽  
Author(s):  
Guo Tao Cui ◽  
Zuo Cheng Wang ◽  
Tao Sun ◽  
Wei Min Guo ◽  
Jun Qing Gao
Keyword(s):  
Impact Toughness ◽  
Impact Energy ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Total Oxygen ◽  
Transmission Electron ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness ◽  
Hot Rolled ◽  
The Impact

In this research, trace boron (4ppm, 8ppm, 11ppm) was added into the Nb-added HSLA H-beams. The impact toughness of H-beams with/without boron was examined by Charpy impact test (V-notch). The morphologies of the microstructure and the fracture surfaces of the impact specimens were observed by metalloscope, stereomicroscope and electron probe. The experimental results prove that the absorbed impact energy at -40°C for the 4ppm, 8ppm, 11ppm boron-added steels respectively reaches up to 80J, 126J, 85J from 15J and H-beams with boron have a lower FATT than that without boron. It is also found that the total oxygen content affects the absorbed impact energy to a certain extent. It is discovered by transmission electron microscope (TEM) that boron mainly exists in solid solution state, except that a little amount of Fe23(C, B)6is formed at the grain boundaries, and the distribution of Nb(C, N) is also influenced by boron addition.

Effect of Heat Treatment on Microstructure and Mechanical Properties of EH36 Alloy

2014 ◽  
Vol 487 ◽  
pp. 177-180 ◽  
Author(s):  
Xiao Dong Luo ◽  
Hao Liu ◽  
Yong Xiang Zhu ◽  
Cai Yu Zheng
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Optical Microscope ◽  
Controlled Rolling ◽  
Plate Steel ◽  
Controlled Cooling ◽  
Impact Performance ◽  
Mechanics Performance ◽  
Temperature Impact ◽  
Quenching And Tempering

The appropriate heat treatment process may obviously enhance the material mechanics performance, lengthens the service life of the machine parts , reduces the exploitation conditions of the material . This article uses mechanical properties test and the optical microscope research quenching and tempering comprehensive heat treatment craft is 15mm controls to thickness controlled rolling and controlled cooling (TMCP) condition tissue and the properties of the EH36 level ship plate steel influence. The result indicated that, after the heat treatment the TMCP condition ship plate steel overall performance has enhances greatly, although has the drop slightly in the intensity, but its plasticity, the low temperature impact performance all has the distinct improvement in particular.

Microstructure and Properties of Weld CGHAZ under Different Heat Input for X90 Pipeline Steel

2016 ◽  
Vol 850 ◽  
pp. 943-949
Author(s):  
Liu Qing Yang ◽  
Yong Li Sui ◽  
Pei Pei Xia ◽  
Hai Hong Zhao ◽  
Zhang Hua Yin
Keyword(s):  
Impact Toughness ◽  
Impact Energy ◽  
Heat Input ◽  
Pipeline Steel ◽  
Charpy Impact ◽  
Optical Microscope ◽  
Granular Bainite ◽  
Alloy Content ◽  
Low Temperature Impact Toughness ◽  
The Impact

Two kinds of industry trial X90 pipeline steels which have different chemical composition were chosen as test objects, and the grain coarsening, microstructural characteristics and the variation rules of low-temperature impact toughness in weld CGHAZ of this two steel under different welding heat input were studied by physical thermal simulation technology, SEM, optical microscope and Charpy impact tests. The results showed that the microstructure in weld CGHAZ of 1# steel was mainly bainite ferrite (BF) and most of the M/A constituents were blocky or short rod-like; the grains of 2# steel were coarse and there was much granular bainite (GB). Meanwhile M/A constituents became coarser and their morphology changed from block to long bar; alloy content of X90 pipeline steel under different weld heat input had great effect on the grain size of original austenite. When heat input was lower than 20KJ/cm, the impact toughness in CGHAZ of lower alloy content pipeline steel was good; as heat input increased, impact toughness in CGHAZ of 1# steel increased to the values between 260J and 300J when heat input was between 20KJ/cm and 25KJ/cm and the dispersion of impact energy was small. The impact toughness of 2# steel decreased gradually and the impact energy had the obvious dispersion.

Effects of Heat Treatment on Microstructure Parameters, Mechanical Properties and Cold Resistance of Sparingly Alloyed High-Strength Steel

2021 ◽  
Vol 410 ◽  
pp. 197-202
Author(s):  
Pavel P. Poleckov ◽  
Olga A. Nikitenko ◽  
Alla S. Kuznetsova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cold Resistance ◽  
Heating Temperature ◽  
High Strength ◽  
Steel Microstructure ◽  
Treatment Conditions ◽  
Microstructure Parameters ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness

This study considers the influence of various heat treatment conditions on the change of steel microstructure parameters, mechanical properties and cold resistance at a temperature of-60 °C. The common behavior of these properties is considered depending on the heating temperature used for quenching and subsequent tempering. Based on the obtained results, heat treatment conditions are proposed that provide a combination of a guaranteed yield point σ0.2 ≥600 N/mm2 with a low-temperature impact toughness KCV-60 ≥50 J/cm2 and plasticity δ5 ≥17%. The obtained research results are intended for industrial use at the mill "5000" site of MMK PJSC.

Design of a novel HSLA steel with a combination of high strength (140–160 ksi) and excellent toughness

2021 ◽  
Vol 112 (10) ◽  
pp. 800-811
Author(s):  
Mehdi Soltan Ali Nezhad ◽  
Sadegh Ghazvinian ◽  
Mahmoud Amirsalehi ◽  
Amir Momeni
Keyword(s):  
Impact Toughness ◽  
Yield Strength ◽  
Hsla Steel ◽  
Charpy Impact ◽  
High Strength ◽  
Controlled Rolling ◽  
The Other ◽  
Grain Structure ◽  
Charpy Impact Toughness ◽  
Fine Grain

Abstract Three steels were designed based on HSLA-100 with additional levels of Mn, Ni, Cr and Cu. The steels were prepared by controlled rolling and tempered at temperatures in range of 550–700°C. The continuous cooling time curves were shifted to longer times and lower temperatures with the increased tendency for the formation of martensite at lower cooling rates. The microstructures revealed that controlled rolling results in austenite with uniform fine grain structure. The steel with the highest amount of Mn showed the greatest strength after tempering at 750 °C. The top strength was attributed to the formation of Cu-rich particles. The steel with 1.03 wt.% Mn, tempered at 650 °C exhibited the best Charpy impact toughness at –85°C. On the other hand, the steel that contained 2.11 wt.% Mn and tempered at 700 °C showed the highest yield strength of 1 097.5 MPa (∼159 ksi) and an impact toughness of 41.6 J at –85°C.

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