Enhancement of Reaction of Zinc on Superficially Nanocrystallized IF Steel by Near Surface-Severe Plasitc Deformation

2006 ◽  
Vol 512 ◽  
pp. 361-366 ◽  
Author(s):  
Yoritoshi Minamino ◽  
Nobuhiro Tsuji ◽  
Yuichiro Koizumi ◽  
Y. Nakamizo ◽  
M. Sato ◽  
...  
Keyword(s):  
Boundary Diffusion ◽  
Volume Diffusion ◽  
Interface Reaction ◽  
Layer Growth ◽  
If Steel ◽  
Layer Width ◽  
Near Surface ◽  
Coarse Grains ◽  
Cold Rolled ◽  
Diffusion Mass

The reaction between the zinc plate (ZP) and the IF steel with near surface ultra fine grains (NSUFG) structure with grain size of about 89 nm was studied in temperature range of 473K to 623K in order to elucidate the temperature dependence of the reactions and its mechanism, by comparison with the reactions of ZP to coarse grains (CG) sheet, superficial cold rolled CG sheet (CG+R) and superficial cold rolled NSUFG sheet (NSUFG+R). It was found that this NSUFG structure considerably affected reactions between IF steel and ZP. There was almost no effect of superficial cold rolling on their reactions, but the NSUFG structure dramatically enhanced the reactions. The incubation times for appearance of the reaction layer and its layer width of ZP /(NSUFG or NSUFG+R) reactions are shorter and thicker than those of the ZP/(CG or CG+R) ones. The activation energy for reaction was 107kJ/mol, which indicates that the volume diffusion in zinc side and the grain boundary diffusion in the iron side play an important role in the reaction. The layer growth up to the layer thickness less than about 10µm was controlled mainly by the interface reaction and it over about 10µm mainly by the diffusion mass transfer.

Retention coefficients and thermal release profiles of ion-injected argon from silicates and iron

1970 ◽  
Vol 48 (12) ◽  
pp. 1472-1479
Author(s):  
Harry C. Lord III
Keyword(s):  
Volume Diffusion ◽  
Ion Irradiation ◽  
Defect Diffusion ◽  
Substrate Composition ◽  
Retention Coefficient ◽  
Thermal Release ◽  
Argon Concentration ◽  
Cold Rolled ◽  
Argon Ions ◽  
Release Profiles

Thermal release profiles and retention coefficients of injected argon ions were investigated as functions of substrate composition and prior ion-irradiation history. Samples of forsterite, enstatite, oligoclase, obsidian, and cold-rolled steel were irradiated with various sequences of 1 keV H+, 4 keV He+, and 40 keV Ar+. The release temperature of the maximum argon concentration was found to be a function of incident Ar+ dose and pre-irradiation history but not substrate composition. The hydrogen or helium pre-irradiation converted the volume diffusion argon release to a low temperature defect diffusion release. An increase in the incident dose of Ar+ ions resulted in increasing the percentage of the argon released by defect diffusion, and also decreased the argon retention coefficient.

An Study of Nanoscale Mechanical Twins in GH4169 Alloy by Laser Shot Peening Processing

2021 ◽  
Vol 1027 ◽  
pp. 155-162
Author(s):  
Qiang Wang
Keyword(s):  
Shot Peening ◽  
Electron Backscatter Diffraction ◽  
Laser Shot ◽  
Near Surface ◽  
Refined Grains ◽  
Transmission Electron ◽  
Coarse Grains ◽  
Mechanical Twins ◽  
Backscatter Diffraction ◽  
Gh4169 Alloy

In order to study the mechanism of the fatigue strengthening using laser shot peening in GH4169 alloy, micro-structural and nanoscale mechanical twins (MT) at different depth below the top surface subjected to laser shot peening processing (LSP) were investigated by means of electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) observations. In terms of the experimental observations and analyses, the formation of refined grains and nanoscale MT mechanism at the near surface of GH4169 alloy as a function of LSP treament can be summarized as follows: (i) two direction low density of MTs divide the initial coarse grains into submicron rhombic blocks; (ii) high density of MTs aligned in two directions subdivide the submicron rhombic blocks into nanoscale rhombic MT blocks; (iii) the third direction MT further refine the nanoscale rhombic MT blocks into nanoscale triangular MT blocks; (iv) some of subdivided blocks evolve into refined grains. An ultra-high strain rate induced by ultra-short laser pulse plays a key role in the formation of refined grains and nanoscale MT during plastic deformation of GH4169 alloy subjected to LSP treatment.

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.

Flow stress and microstructure of the cold-rolled IF-steel

2003 ◽  
Vol 356 (1-2) ◽  
pp. 37-42 ◽  
Author(s):  
B.L. Li ◽  
W.Q. Cao ◽  
Q. Liu ◽  
W. Liu
Keyword(s):  
Flow Stress ◽  
If Steel ◽  
Cold Rolled

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.

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