Effect of Annealing on Microstructure and Corrosion Behavior of Interstitial Free Steel

Interstitial free steels with various grain sizes and textures were prepared by cold-rolling followed by an annealing process. The effect of grain size, crystallographic orientations and stored energy on corrosion behavior of interstitial free steel was investigated. It was found that the deformed microstructure and dislocation boundaries were consumed by recrystallizing grains during annealing. The average grain size increase ranging from 0.61 μm to 11 μm and the volume fraction of recrystallized grains was about 96% after annealing for 64 h; meanwhile, the γ fiber was the dominated recrystallized texture component. The stored energy gradually decreased due to the reduction in dislocation density by annealing. The potentiodynamic polarization and Nyquist plots show that the corrosion potential exhibits a more positive shift and depressed capacitive semicircle radius increase with rising annealing time. The 64 h annealed specimens had the biggest depressed semicircle in the Nyquist plots and the highest positive corrosion potential, which indicates the enhancement of corrosion resistance. Such an improvement of corrosion resistance is attributed to the increase in the volume fraction of the γ fiber and decrease in the stored energy.

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Study of Corrosion Behavior in Resistance Spot Welds of Thin Sheets of Zinc-Coated Interstitial-Free Steel

Journal of Materials Engineering and Performance ◽

10.1007/s11665-021-05474-0 ◽

2021 ◽

Author(s):

Parsa Pishva ◽

Sajad Salimi Beni ◽

Masoud Atapour ◽

Mohammad Reza Salmani ◽

Rouholah Ashiri

Keyword(s):

Corrosion Behavior ◽

Interstitial Free ◽

Thin Sheets ◽

Spot Welds ◽

Resistance Spot ◽

Resistance Spot Welds ◽

Interstitial Free Steel

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Development of Al–Mg–Si alloy performance by addition of grain refiner Al–5Ti–1B alloy

Science Progress ◽

10.1177/00368504211029469 ◽

2021 ◽

Vol 104 (2) ◽

pp. 003685042110294

Author(s):

Khaled Abd El-Aziz ◽

Emad M Ahmed ◽

Abdulaziz H Alghtani ◽

Bassem F Felemban ◽

Hafiz T Ali ◽

...

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Corrosion Resistance ◽

Testing Machine ◽

Dendritic Structure ◽

Grain Refiner ◽

Corrosion Properties ◽

Average Grain Size ◽

Structural Applications ◽

Alloy Addition

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.

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An Assessment of Bulk and Local Stored Energy Measurements in Ultrafine Grained Interstitial Free Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.89-91.244 ◽

2010 ◽

Vol 89-91 ◽

pp. 244-249 ◽

Cited By ~ 1

Author(s):

Sujoy S. Hazra ◽

Azdiar A. Gazder ◽

Elena V. Pereloma

Keyword(s):

Profile Analysis ◽

Energy Estimates ◽

Internal Stresses ◽

Line Profile Analysis ◽

Interstitial Free ◽

Stored Energy ◽

Scanning Calorimetry ◽

Angular Pressing ◽

Ultrafine Grained ◽

Interstitial Free Steel

The evolution of stored energy and associated thermal behaviour was investigated for an ultrafine grained Ti-IF steel severely deformed by Equal Channel Angular Pressing (ECAP) followed by cold rolling at ambient and liquid nitrogen temperatures. Bulk stored energy measurements by Differential Scanning Calorimetry (DSC) returned 350-600 whereas local stored energy estimates from microhardness, Electron Back-Scattering Diffraction (EBSD) and X-ray line profile analysis resulted in 5-140 . Higher bulk stored energy values correspond to the enthalpy release from all sources of strain in the material volume as well as Ti precipitation during annealing while the lower local stored energy range alludes only to dislocation content or internal stresses. An apparent activation energy of 500-550 suggests sluggish recrystallisation due to excess of Ti in solid solution.

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Microstructural Control of Ductile Crack Propagation in TMCP HSLA Pipeline Steels

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.922.568 ◽

2014 ◽

Vol 922 ◽

pp. 568-573

Author(s):

Victor Carretero Olalla ◽

N. Sanchez Mouriño ◽

Philippe Thibaux ◽

Leo Kestens ◽

Roumen H. Petrov

Keyword(s):

Grain Size ◽

Crack Propagation ◽

Volume Fraction ◽

Main Role ◽

Charpy Test ◽

Initiation And Propagation ◽

Average Grain Size ◽

Main Disadvantage ◽

Steel Grades ◽

Increasing Demand

Control of ductile fracture propagation is one of the major concerns for pipeline industry, particularly with the increasing demand of new control rolled steel grades required to maintain integrity at high operational pressures. The objective of this research is to understand which microstructural features govern crack propagation, and to analyse the effect of two of them (average grain size, and volume fraction of pearlite). The main disadvantage during classical Charpy test was to discriminate the crack initiation and propagation energy during fracture of a notched sample. The initiation appears to be caused by the stress state in the neighbouring of Ti-containing precipitates or pearlite particles (no presence of M/A constituents or MnS inclusions was detected in the evaluated grades), propagation-arrest of the crack is assumed to play the main role concerning the control of fracture. Our approach to characterize the fracture resistance is to measure the energy absorbed during the crack propagation stage by means of load-displacement curves obtained via instrumented Charpy test. It was observed that the energy absorbed during crack propagation is not influenced by the average grain size but by the fraction and the morphological (banded-not banded) distribution of second pearlitic phase. This suggests that a different approach to characterize the heterogeneities in grain size clustering might be followed to correlate the energy measured during crack propagation and the morphological features of the steel.

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Study on Dynamic Recrystallization Behavior in Deformed Austenite of 52100 Steel by Using JMAK-Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.1833 ◽

2013 ◽

Vol 275-277 ◽

pp. 1833-1837

Author(s):

Ke Lu Wang ◽

Shi Qiang Lu ◽

Xin Li ◽

Xian Juan Dong

Keyword(s):

Grain Size ◽

Dynamic Recrystallization ◽

Hot Deformation ◽

Volume Fraction ◽

True Strain ◽

Strain And Strain Rate ◽

Average Grain Size ◽

Dynamic Recrystallization Behavior ◽

Simulation And Experiment ◽

Good Agreement

A Johnson-Mehl-Avrami-Kolmogorov (JMAK)-model was established for dynamic recrystallization in hot deformation process of 52100 steel. The effects of hot deformation temperature, true strain and strain rate on the microstructural evolution of the steel were physically studied by using Gleeble-1500 thermo-mechanical simulator and the experimental results were used for validation of the JMAK-model. Through simulation and experiment, it is found that the predicted results of DRX volume fraction, DRX grain size and average grain size are in good agreement with the experimental ones.

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Thermal Stability of Ultrafine-Grained Pure Titanium Processed by High-Pressure Torsion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.338 ◽

2021 ◽

Vol 1016 ◽

pp. 338-344

Author(s):

Wan Ji Chen ◽

Jie Xu ◽

De Tong Liu ◽

De Bin Shan ◽

Bin Guo ◽

...

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Grain Size ◽

High Pressure ◽

Annealing Temperature ◽

High Pressure Torsion ◽

Stored Energy ◽

Ultrafine Grained ◽

Average Grain Size ◽

Thermal Stability Of

High-pressure torsion (HPT) was conducted under 6.0 GPa on commercial purity titanium up to 10 turns. An ultrafine-grained (UFG) pure Ti with an average grain size of ~96 nm was obtained. The thermal properties of these samples were studied by using differential scanning calorimeter (DSC) which allowed the quantitative determination of the evolution of stored energy, the recrystallization temperatures, the activation energy involved in the recrystallization of the material and the evolution of the recrystallized fraction with temperature. The results show that the stored energy increases, beyond which the stored energy seems to level off to a saturated value with increase of HPT up to 5 turns. An average activation energy of about 101 kJ/mol for the recrystallization of 5 turns samples was determined. Also, the thermal stability of the grains of the 5 turns samples with subsequent heat treatments were investigated by microstructural analysis and Vickers microhardness measurements. It is shown that the average grain size remains below 246 nm when the annealing temperature is below 500 °C, and the size of the grains increases significantly for samples at the annealing temperature of 600 °C.

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