Characterization of X80 Grade Linepipe Steel Coil With 24 mm Thickness

2012 ◽  
Author(s):  
Nuria Sanchez ◽  
Nenad Ilić ◽  
Martin Liebeherr
Keyword(s):  
Volume Fraction ◽  
Shear Fracture ◽  
High Strength ◽  
Microstructural Characterization ◽  
Steel Coil ◽  
Microstructural Parameters ◽  
High Toughness ◽  
Average Grain Size ◽  
Fracture Appearance

High strength and high toughness at low temperatures on heavy wall thickness skelp is required to build high pressure gas transportation pipelines. Detailed mechanical and microstructural characterization was carried on 24mm thick ArcelorMittal X80 coils in order to identify the microstructure control required to reach high toughness as determined by the shear fracture appearance after DWTT testing. Detailed microstructural characterization through thickness reveals that the microstructure gradient described by a systematic increase of the average grain size between surface and middle thickness of the strip and the increment of the volume fraction of M/A (martensite/ retained austenite) are the key microstructural parameters to control in order to ensure the adequate toughness of the material. The obtained high toughness of the coils indicates that the microstructure, controlled by an optimized rolling and cooling practice, is homogeneous through thickness of heavy wall linepipe grades.

scholarly journals Mechanical properties, deformation and fracture mechanisms of bimodal Cu under tensile test

2021 ◽  
Vol 60 (1) ◽  
pp. 15-24
Author(s):  
Silu Liu ◽  
Yonghao Zhao
Keyword(s):  
Yield Strength ◽  
Grain Refinement ◽  
Volume Fraction ◽  
Shear Fracture ◽  
High Strength ◽  
Tensile Specimen ◽  
Deformation Mechanisms ◽  
Fracture Mechanisms ◽  
Fracture Angle ◽  
Area Reduction

Abstract Metals with a bimodal grain size distribution have been found to have both high strength and good ductility. However, the coordinated deformation mechanisms underneath the ultrafine-grains (UFGs) and coarse grains (CGs) still remain undiscovered yet. In present work, a bimodal Cu with 80% volume fraction of recrystallized micro-grains was prepared by the annealing of equal-channel angular pressing (ECAP) processed ultrafine grained Cu at 473 K for 40 min. The bimodal Cu has an optimal strength-ductility combination (yield strength of 220 MPa and ductility of 34%), a larger shear fracture angle of 83∘ and a larger area reduction of 78% compared with the as-ECAPed UFG Cu (yield strength of 410 MPa, ductility of 16%, shear fracture angle of 70∘, area reduction of 69%). Grain refinement of recrystallized micro-grains and detwinning of annealing growth twins were observed in the fractured bimodal Cu tensile specimen. The underlying deformation mechanisms for grain refinement and detwinning were analyzed and discussed.

Effect of nitrogen on transformation behavior and intragranular ferrite formation in a V–Ti microalloyed steel for forging

2018 ◽  
Vol 115 (3) ◽  
pp. 311 ◽  
Author(s):  
Ningbo Zhou ◽  
Fan Zhao ◽  
Yiqun Liu ◽  
Bo Jiang ◽  
Chaolei Zhang ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Volume Fraction ◽  
Microalloyed Steel ◽  
High Strength ◽  
Transformation Behavior ◽  
Ferrite Formation ◽  
High Toughness ◽  
Intragranular Ferrite ◽  
Production Experiment ◽  
Cct Diagrams

The transformation behavior and intragranular ferrite formation in V–Ti microalloyed steel with a nitrogen content of 0.005 wt.% and 0.015 wt.% are studied by the DIL 805A dilatometer. The results show that increasing the nitrogen content has no significant effect on AC1, AC3and MStemperature. However, the continuous cooling transformation (CCT) diagrams are shifted to left side. The minimum cooling rates of bainitc and martensitic transformation are increased from 3 °C/s to 5 °C/s and from 5 °C/s to 10 °C/s, respectively. (Ti, V)(C, N) particles on MnS is the nuclei of intragranular ferrite, and (1 0 0)(Ti, V)(C, N)and (1̅ 0 1̅α) are just misoriented by 6.7°. With the increase of nitrogen content, the number of intragranular ferrite is increased from 73 to 170 per · mm2. The volume fraction of intragranular ferrite is increased from 0.23%∼0.79% to 0.79%∼4.6% at cooling rate of 1 °C/s∼0.1 °C/s. According to the industrial production experiment, the toughness of forging crankshaft is improved by increasing the nitrogen content. It is benefit for achieving fair matching of high strength and high toughness of crankshaft.

Microstructural Characterization of α2 + γ Titanium Aluminides

1997 ◽  
Vol 3 (S2) ◽  
pp. 701-702
Author(s):  
D. J. Larson ◽  
M. K. Miller
Keyword(s):  
Titanium Aluminides ◽  
Base Alloy ◽  
Significant Proportion ◽  
Weight Ratio ◽  
High Strength ◽  
Microstructural Characterization ◽  
Two Phase ◽  
Tial Alloys ◽  
Boron Doped

Two-phase α2+γ TiAl alloys with microalloying additions, Fig. 1, are of interest due to the high strength-to-weight ratio they can provide in automotive and aircraft applications. In boron-doped α2+γTiAl containing Cr, Nb, and W, the B levels were found to be significantly depleted below the nominal alloy content in both the α2 andγ phases. The boron solubilities in the γ and α2 phases were 0.011 ± 0.005 at. % B and 0.003 ± 0.005 at. % B, respectively in Ti-47% Al-2% Cr-1.8% Nb-0.2% W-0.15 % B that was aged for 2 h at 900°C (base alloy). The majority of the B was in a variety of borides including TiB, TiB2 and a Cr-enriched (Ti,Cr)2B precipitate. With the exception of the smaller (< 50 nm thick) Cr-enriched (Ti,Cr)2B precipitates, Fig. 2, most of the borides were larger than ∼100 nm. A significant proportion of the microalloying additions is in these borides, Table 1.

Effect of Processing Route on Mechanical Behavior of C-Mn Multiphase High Strength Cold Rolled Steel

2007 ◽  
Vol 539-543 ◽  
pp. 4375-4380
Author(s):  
Dagoberto Brandão Santos ◽  
Élida G. Neves ◽  
Elena V. Pereloma
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Quantitative Relationship ◽  
High Strength ◽  
Microstructural Characterization ◽  
Processing Route ◽  
Accelerated Cooling ◽  
Microstructural Parameters ◽  
Transmission Electron

The multiphase steels have complex microstructures containing polygonal ferrite, martensite, bainite, carbide and a small amount of retained austenite. This microstructure provides these steels with a high mechanical strength and good ductility. Different thermal cycles were simulated in the laboratory in order to create the microstructures with improved mechanical properties. The samples were heated to various annealing temperatures (740, 760 or 780°C), held for 300 s, and then quickly cooled to 600 or 500°C, where they were soaked for another 300 s and then submitted to the accelerated cooling process, with the rates in the range of 12-30°C/s. The microstructure was examined at the end of each processing route. The mechanical behavior evaluation was made by microhardness testing. The microstructural characterization involved optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM). The use of multiple regression analysis allowed the establishment of quantitative relationship between the microstructural parameters, cooling rates and mechanical properties of the steel.

Effect of Microalloying Elements on Mechanical Properties in the High Strength Low Alloy Steel

2015 ◽  
Vol 830-831 ◽  
pp. 231-233 ◽  
Author(s):  
P.K. Mandal ◽  
Ravi Kant
Keyword(s):  
Mechanical Properties ◽  
Hsla Steel ◽  
High Strength ◽  
Microstructural Characterization ◽  
Strengthening Mechanism ◽  
Treatment Processes ◽  
Heating Treatment ◽  
Secondary Precipitates ◽  
Microalloying Elements

The effect of microalloying elements in Ti-Nb-V containing high strength low alloy (HSLA) steel has been investigated in the present study. The addition of low alloying elements (such as Ti, Nb and V) and distinct heating treatment processes has been used to improve the mechanical properties of HSLA steel. The effect on the microstructure and mechanical properties of normalizing treatment (at 950°C) of as forged steel has been investigated. The microstructural characterization of microalloyed HSLA steel is carried out by using different techniques such as optical microscopy, scanning electron microscopy (SEM) etc. The hardness, tensile testing and Charpy V notch impact tests are performed to study the mechanical behaviour of the alloy. It has been concluded that the precipitation strengthening mechanism for the improvement of impact toughness due to secondary precipitates such as TiN, Ti(C, N), VN etc.

Microstructural and Electrical Characterization of Barium Strontium Titanate Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
Yujing Wu ◽  
Elizabeth G. Jacobs ◽  
Russell F. Pinizzotto ◽  
Robert Tsu ◽  
Hung-Yu Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Electrical Characterization ◽  
Microstructural Characterization ◽  
Plan View ◽  
Pt Electrodes ◽  
Average Grain Size ◽  
Metal Organic ◽  
Bst Thin Film ◽  
Anneal Time

ABSTRACTThe kinetics of BST thin film grain nucleation and growth caused by rapid thermal annealing have been investigated. A series of Ba0.67Sr0.33Tii0.5O3 films were deposited on Pt electrodes using a metal-organic decomposition process. The effects of anneal time and temperature on BST grain sizes were studied by altering the processing conditions during RTA. A series of films were annealed by RTA at temperatures ranging from 550°C to 950°C for times ranging from 30 to 120 seconds. Crystallographic and microstructural characterization were done using XRD and TEM. The XRD results indicated that BST grain size increased with increasing anneal temperature, but was not affected by anneal time. Plan-view TEM indicated that BST grains were imbedded in an amorphous matrix. The average grain size was on the order of 200 Å.

Microstructural characterization of high strength and high conductivity nanocomposite wires

1996 ◽  
Vol 34 (7) ◽  
pp. 1067-1073 ◽  
Author(s):  
F. Dupouy ◽  
E. Snoeck ◽  
M.J. Casanove ◽  
C. Roucau ◽  
J.P. Peyrade ◽  
...  
Keyword(s):  
High Strength ◽  
Microstructural Characterization ◽  
High Conductivity

Microstructural Characterization of Clad Interface in Welds of Ni-Cr-Mo High Strength Low Alloy Steel

2011 ◽  
Vol 49 (08) ◽  
pp. 628-634 ◽  
Author(s):  
Hong-Eun Kim ◽  
Ki-Hyoung Lee ◽  
Min-Chul Kim ◽  
Ho-Jin Lee ◽  
Keong-Ho Kim ◽  
...  
Keyword(s):  
Alloy Steel ◽  
High Strength ◽  
Microstructural Characterization ◽  
Low Alloy Steel

Research on Multi-Artificial Aging Applied to Aluminum Alloy 7150 Plate

2012 ◽  
Vol 706-709 ◽  
pp. 340-345
Author(s):  
Zhi Hui Li ◽  
Bai Qing Xiong ◽  
Yon Gan Zhang ◽  
Xin Yu Lu ◽  
Zhen Bo He ◽  
...  
Keyword(s):  
Tensile Property ◽  
Artificial Aging ◽  
Volume Fraction ◽  
Electron Backscatter Diffraction ◽  
High Strength ◽  
Microstructural Characterization ◽  
Grain Structure ◽  
Artificial Ageing ◽  
Thickness Direction ◽  
Near Surface

The AA 7150-T351, in the form of 40 mm thick plates, was subjected to single-stage aging leading to peak aged condition, and two selected multi-artificial aging treatments leading to the over aged conditions. The microstructural differences along the thickness direction of the AA 7150-T351 plate were investigated using OM and electron backscatter diffraction (EBSD) technique, and the microstructural characterization was studied at different stages of multi-artificial ageing process by transmission electron microscopy. Tensile properties and electrical conductivity measurements were used to evaluate the property homogeneity along the thickness direction of the plate under various artificial aging tempers. It was revealed that the microstructural features and tensile property are inhomogeneous in different layers along the thickness direction, and both grain structure and tensile property exhibit appreciable anisotropy at the same thickness layer. The volume fraction of recrystallized grain of T351 plate in the near surface layer is higher than that in the center layer remarkably. It is also shown that two selected multi-artificial aging tempers can provide optimal precipitates in matrix and at grain boundaries, which gives rise to a combination of high strength and stress corrosion cracking (SCC) resistance in such materials.

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