Boron and Phosphorus Segregation Behavior at Grain Boundary in a Ti-If Steel after Annealing

2010 ◽  
Vol 152-153 ◽  
pp. 320-325 ◽  
Author(s):  
Xin Li Song ◽  
Ze Xi Yuan ◽  
Juan Jia ◽  
Ping He Li ◽  
Di Wang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Rolling Direction ◽  
Optical Microscope ◽  
If Steel ◽  
Microstructure Development ◽  
Rolled Sample ◽  
Phosphorus Segregation ◽  
Segregation Behavior ◽  
Cold Roll ◽  
Cold Rolled

The cold roll B-added Ti-IF steel is annealed for different times at 810 oC. The microstructure development is studied by Optical Microscope（OM） and the concentration of boron and phosphorus segregation at grain boundary is measured by Auger electron spectroscopy（AES）. The result shows that the grain of the cold- rolled sample is elongated along the rolling direction and the elongated grains become into equi-axis shape after annealing 60 to 180sec. Boron and phosphorus segregated at gain boundaries. But boron’s concentration at grain boundary is higher than that of phosphorus and increase from 5at.% or so to about 10at% after annealing 150sec, Then boron’s concentration decrease slowly to 8at.% at 240sec. While phosphorus’s concentration increase to the max of 2.5at.% or so at 120sec, then its concentration decrease to 1at.% or so after annealing 240sec.

Phosphorus segregation behavior at the grain boundary in a Ti-IF steel after annealing

2010 ◽  
Vol 63 (4) ◽  
pp. 446-448 ◽  
Author(s):  
X.L. Song ◽  
Z.X. Yuan ◽  
J. Jia ◽  
D. Wang ◽  
L.X. Fan
Keyword(s):  
Grain Boundary ◽  
If Steel ◽  
Phosphorus Segregation ◽  
Segregation Behavior

Structure and Mechanical Properties of Asymmetrically Rolled IF Steel Sheet

2010 ◽  
Vol 654-656 ◽  
pp. 1255-1258 ◽  
Author(s):  
Dmitry Orlov ◽  
Rimma Lapovok ◽  
László S. Tóth ◽  
Ilana B. Timokhina ◽  
Peter D. Hodgson ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Steel Sheet ◽  
Rolling Direction ◽  
If Steel ◽  
Asymmetric Rolling ◽  
Cold Rolled ◽  
Hot Rolled ◽  
If Steel Sheet

As-received hot-rolled 5.6 mm thick IF steel sheet was symmetrically/asymmetrically cold rolled at room temperature down to 1.9 mm. The asymmetric rolling was carried out in monotonic (an idle roll is always on the same side of the sheet) and reversal (the sheet was turned 180º around the rolling direction between passes) modes. Microstructure, texture and mechanical properties were analysed. The observed differences in structure and mechanical properties were modest, and therefore further investigation of the effects of other kinds of asymmetry is suggested.

Degradation Characteristics of Mg-1,6Gd Alloy at Low Thickness Reduction of Warm Rolling

2020 ◽  
Vol 1000 ◽  
pp. 139-147
Author(s):  
Ahmad Nabil Faiz Hidayat ◽  
Ahmad Zakiyuddin ◽  
Sri Harjanto ◽  
Oknovia Susanti
Keyword(s):  
Hydrogen Evolution ◽  
Electrochemical Impedance ◽  
Immersion Test ◽  
Optical Microscope ◽  
Warm Rolling ◽  
Passive Layer ◽  
Corrosion Mechanism ◽  
Rolled Sample ◽  
Cold Roll ◽  
Polarization Test

Magnesium has been developed as a biodegradable bone implant material due to its similarity in elasticity modulus of bone. However, magnesium has a higher corrosion rate and a lower strength. Gadolinium is alloyed to magnesium in order to improve the corrosion resistance and then rolled to improve the strength due to grain refinement in rolling. Cold roll produced the finest grain, but magnesium has a poor formability. Due to this fact, warm rolling with temperature 247 – 375 oC is applied. Optical Microscope, Scanning Electron Microscope (SEM), and Energy Dispersive Spectrometry (EDS) are used for characterization. Electrochemical Impedance Spectroscopy (EIS) and Polarization test were carried out to observe the corrosion mechanism of Mg-Gd in SBF Kokubo to replicate a human body condition. The result of polarization test shows that the cross-rolled sample experienced an increase in E corr, with 0,15 and –0,048 V due to a better distribution of Gadolinium. EIS states that the single pass rolled sample has a stronger passive layer with 116 and 126 kΩ value of Rf due to a smaller grain size which resulted a fewer compression stress. The hydrogen evolution was also observed with immersion test. Keywords: uni-directional rolling, cross-directional rolling, corrosion, simulated body fluid, hydrogen evolution.

The Study on the Low Yield Strength for Super Fine Grain and High Strength Bearing Nb if Steel

2011 ◽  
Vol 335-336 ◽  
pp. 615-618
Author(s):  
Hong Mei Zhang ◽  
Li Feng Qiao
Keyword(s):  
Solid Solution ◽  
Yield Strength ◽  
Grain Boundary ◽  
High Strength ◽  
If Steel ◽  
Rolled Steel ◽  
Steel Sheets ◽  
Fine Grain ◽  
Cold Rolled ◽  
R Value

The cold rolling and simulative continuous annealing experiments after rolling were carried out in the laboratory on the base of super fine grain (SFG) steel sheet. The microstructure and the second-phase particles precipitated behavior were analyzed by the technology of OM, TEM and EDX. It is found that the fined Nb(C, N) can be formed by adding micro-alloy element Nb. It is noted that the yield strength is low as well as the tensile strength is high by the PFZ which is free of precipitate called precipitated free zone on the one side of the grain boundary. Contrast to the conventional IF steel, the super fine grain steel has super fine grains and gives excellent press-formability such as low yield strength, high r-value（the plastic strain ratio）. High strength cold-rolled steel sheets (HSS) with high formability have been developed in the last decade, in which the major strengthening method was solid-solution hardening with silicon, manganese and phosphorous [1-3]. When the IF steel is strengthened with the high amount of solid-solution elements, it becomes susceptible to the secondary work embrittlement because of the lack of grain boundary strength [4-6]. In this paper, High strength cold-rolled steel sheets (HSS) with high formability have been developed for the IF steel-bases. The grain refinement and precipitation hardening are achieved by means of the fine distribution of carbide under the appropriate combination of the relatively higher carbon content near 0.0070 mass% with niobium. As the result, this type of IF-HSS has been successfully developed to reach a higher r-value as compared with the conventional IF-HSS.

Grain-Boundary Segregation of Phosphorus and Inter-Granular Fracture Behavior under Low Tensile Stresses

2012 ◽  
Vol 525-526 ◽  
pp. 273-276 ◽  
Author(s):  
Yu Dong Fu ◽  
Qing Fen Li ◽  
Wei Xin Sun
Keyword(s):  
Grain Boundary ◽  
Intergranular Fracture ◽  
Fracture Behavior ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Fracture Rate ◽  
Phosphorus Segregation ◽  
Tensile Stresses ◽  
Segregation Behavior ◽  
Segregation Level

The present work is an effort to provide experimental results focusing on segregation behavior of phosphorus at grain boundary and the intergranular fracture behavio under low tensile stresses. AES (Auger electron spectroscopy) experiments and dynamic analyses on the non-equilibrium grain-boundary segregation (NGS) of phosphorus and the SEM photos of intergranular fracture in Auger specimens in 12Cr1MoV steel were carried out in this paper. The variation of phosphorus segregation level in grain boundary under different low tensile stresses and at different temperature were obtained. Results show that NGS of phosphorus occurred in the experimental steel while subjected to low tensile stresses. Maximum values of phosphorus segregation level were obtained at the critical times. SEM photos of intergranular fracture in Auger specimens of the test steel show that the intergranular fracture rate increased with increasing concentration of phosphorus. The intergranular fracture behavior is accordant with the segregation behavior of phosphorus at grain boundary.

Microstructure and Texture Evolution in Cold Rolled Interstitial Free (IF) Steel Sheet during Annealing under AC Magnetic Field

2010 ◽  
Vol 638-642 ◽  
pp. 2781-2786
Author(s):  
Chang Shu He ◽  
Sadahiro Tsurekawa ◽  
Hiroyuki Kokawa ◽  
Xiang Zhao ◽  
Liang Zuo
Keyword(s):  
Magnetic Field ◽  
Steel Sheet ◽  
Texture Evolution ◽  
Rolling Direction ◽  
Recrystallization Annealing ◽  
Interstitial Free ◽  
If Steel ◽  
Ac Magnetic Field ◽  
Cold Rolled ◽  
If Steel Sheet

An AC magnetic field (0.5Tesla) is applied with the field direction perpendicular to the rolling direction during annealing of a 76% cold-rolled IF steel sheet. Microstructure and texture evolution in the as-annealed specimens were determined using SEM based OIM technique. It is found that the recrystallization is noticeably retarded by AC magnetic field annealing. At the early stage of recrystallization (annealing at 650°C for 30min), the development of (111) <123> orientations was favored by the AC magnetic field. With progress of recrystallization (annealing at 700°C and 750°C for 30min), the applied AC magnetic field suppressed the development of γ-fiber recrystallization textures to some extent.

Effect of Annealing Temperature on Phosphorus Segregation at Grain Boundary in a Ti-IF Steel

2012 ◽  
Vol 430-432 ◽  
pp. 724-728 ◽  
Author(s):  
Xin Li Song ◽  
Ze Xi Yuan ◽  
Juan Jia ◽  
Li Xia Fan ◽  
Kun Peng ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Auger Electron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Intergranular Crack ◽  
Annealing Temperature ◽  
Phosphorus Concentration ◽  
If Steel ◽  
Secondary Crack ◽  
Phosphorus Segregation

The concentration of phosphorus at grain boundary of the Ti-IF steel annealed for 180sec at 780°C、810°C and 840°C respectively is measured by auger electron spectroscopy (AES). The results show that the segregation concentration of phosphorus at grain boundary decreases with increasing annealing temperature from 780 to 840°C. The maximum phosphorus concentration at grain boundary is 13.5at% or so for the specimen annealed for 180sec at 780°C. Most of the grains are intergranular crack and there are a few secondary crack for the samples annealed at 780°C and 810°C. The grains grow up and the cleavage planes increase with increasing the annealing temperature from 780 to 840°C.

Flow Stress Anisotropy - Effect of Microstructure and Texture in Aluminium and IF Steel

2005 ◽  
Vol 495-497 ◽  
pp. 1541-1546
Author(s):  
Z.J. Li ◽  
Grethe Winther ◽  
Niels Hansen
Keyword(s):  
Flow Stress ◽  
Rolling Direction ◽  
Rolling Plane ◽  
Strengthening Effect ◽  
If Steel ◽  
Tensile Direction ◽  
Stress Anisotropy ◽  
Commercial Purity Aluminium ◽  
Cold Rolled ◽  
Effect Of Microstructure

The effect of microstructure and texture on the flow stress anisotropy in aluminium and IF steel has been investigated. The samples are recrystallized commercial purity aluminium (AA1050) cold rolled to prestrains of 0.05, 0.11 and 0.2, and recrystallized IF steel cold rolled to a prestrain of 0.28. The flow stress anisotropy was measured by tensile testing of specimens cut along different directions in the rolling plane. Pronounced anisotropy was found in both materials in spite of weak textures. The yield stress increases with increasing angle between the tensile direction and the rolling direction at all prestrains. The effect of microstructure and texture on the flow stress anisotropy was modelled by incorporating into a full-constraint Taylor model the strengthening effect of dislocation boundaries. The modelling and experimental results agree well, leading to a discussion of effect of the microstructure and texture on the flow stress anisotropy.

On {h,1,1}, the Recrystallisation Texture of Heavily Cold Rolled BCC Steel

2004 ◽  
Vol 467-470 ◽  
pp. 269-274 ◽  
Author(s):  
Hotaka Homma ◽  
Shuichi Nakamura ◽  
Naoki Yoshinaga
Keyword(s):  
Grain Boundary ◽  
Cold Rolling ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Rolling Direction ◽  
Experimental Results ◽  
Rolled Steel ◽  
Fibre Structure ◽  
Pole Figures ◽  
Cold Rolled

Heavily cold rolled BCC steel has been indicated to generate {411}<148> recrystallisation texture and its family orientations which might be represented as {h,1,1}<1/h,1,2>. As a-fibre structure, or RD//<011> texture is significantly developed during the cold rolling, it is naturally speculated to be the recrystallisation site of {h,1,1}<1/h,1,2> fibre. The present paper prompts to demonstrate the recrystallisation procedure by utilising EBSP-OIM analysis. The first demonstration was carried out with OIM analysis on partially recrystallised cold rolled steel. At the stage of 50% recrystallisation, only ND//<111> texture has appeared for the recrystallised area. {100}<011> - {211}<011> a-fibre remains as deformed structure, and several {h,1,1}<1/h,1,2> grains could be found at the grain boundaries. Therefore, a bi-crystal of {100}<011> was employed to simulate the irregular deformation at the grain boundary. After cold rolling, a warp toward the grain boundary was observed. Although the interior of the {100}<011> single crystal was hardly recrystallised, sharp {411}<148> texture was created along the grain boundary. In order to confirm the phenomenon, another experiment was carried out that a cold rolled {100}<011> single crystal was bent along the rolling direction and annealed. Very sharp {411}<148> recrystallisation texture was formed again at the bent perimeter. These experimental results lead us to conclude that the irregular strain was sufficiently piled at the grain boundary after the heavy deformation and generates {h,1,1}<1/h,1,2> texture. On {100} pole figures, the recrystallisation textures were equivalently scattered around three <100> poles, therefore the rotation relationship around <111> axes with the original orientation was suggested.

Sign in / Sign up

Export Citation Format

Share Document