Analysis of Texture Formation and Microstructure Characteristics of Cold Rolled IF Steel Sheets

2005 ◽  
Vol 495-497 ◽  
pp. 411-416
Author(s):  
Y.X. Cai ◽  
Y.D. Liu ◽  
Yi Nong Wang ◽  
Gang Wang ◽  
Yan Dong Wang ◽  
...  
Keyword(s):  
Interstitial Free ◽  
If Steel ◽  
Texture Formation ◽  
Dislocation Wall ◽  
Microstructure Characteristics ◽  
Steel Sheets ◽  
Transmission Electron ◽  
Cold Rolled ◽  
The Relationship ◽  
Characteristic Microstructure

The aim of this work is to investigate the relationship between the deformation microstructure and texture in cold rolled Interstitial Free (IF) steel sheets. In the present research, the cold rolled IF steel sheets with 10%-50% reductions are used to observe the characteristic microstructure and individual orientations by transmission electron microscopy (TEM) and SAED patterns. The experimental results on inter-granular strain homogeneity and dislocation wall formation are given in details in this paper. The results are explained by the analysis of crystallographic gliding and are helpful to improve the prediction of cold rolling textures.

Effect of Micro-Alloying Elements of Ti, Nb and B on Recrystallization Behavior of Cold-Rolled Interstitial-Free Steel Sheets

2013 ◽  
Vol 753 ◽  
pp. 207-212 ◽  
Author(s):  
Xin Li Song ◽  
Kun Peng ◽  
Ze Xi Yuan ◽  
W.W. Zhu ◽  
J. Jia ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Fibrous Tissue ◽  
Alloying Elements ◽  
Recrystallization Temperature ◽  
Interstitial Free ◽  
If Steel ◽  
Recrystallization Behavior ◽  
Steel Sheets ◽  
Interstitial Free Steel ◽  
Cold Rolled

The effect of micro-alloying elements of niobium and boron and titanium on recrystallization behavior is researched after the cold rolled IF steels are annealed at high temperature. The results show that there is high density dislocation in the cold rolled steel and the microstructure is fibrous tissue. The recrystallization grains appear when the cold steel annealed at 655 °C and then the grains grow up with the annealing temperature increased to 840 °C. The recrystallization temperature and time of B-Ti-IF steel is lower than that of Nb-Ti-IF and Ti-IF steels. The recrystallization activation energy of Nb-Ti-IF steel is 181.7KJ/mol which is 56.6KJ/mol larger than that of B-Ti-IF steel.

scholarly journals STRENGTH AND MICROSTRUCTURE OF COLD-ROLLED IF STEEL

2016 ◽  
Vol 22 (1) ◽  
pp. 35
Author(s):  
Anh-Hoa Bui ◽  
Hoang Le
Keyword(s):  
Steel Plates ◽  
Interstitial Free ◽  
If Steel ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Steel Sheets ◽  
Vacuum Technology ◽  
Cold Rolled ◽  
Soaking Temperature

<p>With the emerge of vacuum technology, it is possible to produce ultra low carbon (ULC) steels with carbon content of less than 0.005 %mass which is called interstitial free (IF) steels. In this study, strength and microstructure of IF steel after cold-rolling have been determined. The initial steel plates were cold-rolled using two different cold reductions (CR) as 80 and 90% in total, thereafter the steel sheets were cut into specimens for tensile test and optical microscopy. Ultimate tensile strength (UTS) of the cold-rolled steel was high (650¸807 MPa), but the elongation (EL) was low (3.5¸5.3%). Meanwhile, UTS of the annealed steels was decreased to 290 MPa when soaking temperature was 800<sup>o</sup>C because of stress relief and recrystallization. It was concluded that higher CR (more severe deformation) increased the strength but decreased the ductility of the IF steels. In consistence with micrograph of the steels, X-ray diffraction (XRD) results showed that microstructure of the cold-rolled and annealed IF steels was only ferrite. Textures, one of the most important factors affecting the recrystallization, were found in cold-rolled steels.</p>

Precipitation Behavior of Warm-Rolled Ti-Stabilized Interstitial-Free (IF) Steel Sheets

2007 ◽  
Vol 353-358 ◽  
pp. 1653-1656 ◽  
Author(s):  
Fu Tao Han ◽  
Zuo Cheng Wang ◽  
Cai Nian Jing ◽  
Wen Ping Zhang
Keyword(s):  
Texture Evolution ◽  
Great Influence ◽  
High Strength ◽  
Recrystallization Annealing ◽  
Interstitial Free ◽  
If Steel ◽  
Precipitation Behavior ◽  
Steel Sheets ◽  
Energy Dispersion Spectrometer ◽  
Transmission Electron

Precipitates have great influence on the recrystallization, texture evolution and thus the final mechanical properties of the Interstitial-Free (IF) steel sheets, however, very few studies have dealt with the precipitation behavior of IF steels warm rolled in ferrite region. In the present work, the precipitate characteristics (type, morphology, size and amount) of warm-rolled ordinary Ti-stabilized Interstitial-Free (Ti-IF) steel and p-added high-strength Ti-IF steel were investigated by Transmission Electron Microscope (TEM) and Energy Dispersion Spectrometer (EDS). The results show that most precipitates in warm-rolled ordinary Ti-IF steels are TiN, TiS, Ti4C2S2 and TiC. Besides these precipitates, a great amount of FeTiP precipitates exist in warm-rolled P-added high-strength Ti-IF steel. The precipitation of FeTiP retards the migration of grain boundary in the recrystallization annealing, so the {111} texture and thus deep drawability of warm-rolled high-strength Ti-IF steel is deteriorated.

Microstructure, Texture and Property of Interstitial-Free (IF) Steel after Ultra-Fast Annealing

2015 ◽  
Vol 1120-1121 ◽  
pp. 1003-1007 ◽  
Author(s):  
He Long Cai ◽  
Jun Sheng Mou ◽  
Zi Yong Hou
Keyword(s):  
Electron Microscopy ◽  
Electron Backscatter Diffraction ◽  
Second Phase ◽  
Interstitial Free ◽  
If Steel ◽  
Steel Sheets ◽  
Transmission Electron ◽  
Second Phase Particles ◽  
Backscatter Diffraction ◽  
Equiaxed Grain

In this paper, common continous annealing (CCA) and ultra-fast annealing (UFA) were carried out on a cold-rolled interstitial-free (IF) steel, respectively. The microstructure of the annealed IF steel was characterized by means of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The mechanical property was examined using tensile test. The optimum annealing process parameters were then obtained. The results showed that, the recrystallization occurs at the temperature in the range of 780-830°C. The fraction of equiaxed grain increases with the annealing temperature increasing. The well combination of mechanical properties and formability was obtained when the IF steel annealed at 820°C, which was the result of the fine dispersed second phase particles. {001} texture was absent in the whole thickness of all the annealed IF steels. In addition, the strongest γ texture was found, and this was a potential way to improve the deep drawability of annealed steel sheets.

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.

Application of Recrystallization Texture Evolution Model to Predict Plastic Formability in Steel Strips

2014 ◽  
Vol 783-786 ◽  
pp. 1954-1960
Author(s):  
Toshiharu Morimoto ◽  
Y. Fuyuki ◽  
A. Yanagida ◽  
Jun Yanagimoto
Keyword(s):  
Recrystallization Texture ◽  
Texture Evolution ◽  
Steel Strip ◽  
Rolling Texture ◽  
Interstitial Free ◽  
If Steel ◽  
Taylor Model ◽  
Steel Strips ◽  
Cold Rolled ◽  
Hot Rolled

T.M.C.P.(Thermo Mechanical Control Processing) has been widely used to improveplastic formability in steel strips. We have produced interstitial free steel(IF steel) strips and ferriticstainless-steel strips through T.M.C.P. rolling method. Optimizing conditions of hot rolling, hotrolled annealing, cold rolling and cold rolled annealing, we developed texture prediction model. Wecan predict rolling texture accurately using the conventional Taylor model. Moreover, we preciselypredict recrystallization texture classifying the total number of microscopic􀀁 slips which arecalculated using the Taylor model. We consider that these calculated results provednucleation-oriented model and two types of recrystallization and grain growth mechanisms exit inour studies. One mechanism is that grains which had the small total number of microscopic slips arepreferred orientation for the hot rolled and annealed ferritic stainless-steel strip. The othermechanism is that grains which had the high total number of microscopic slips are preferredorientation for the cold rolled and annealed IF steel strip.

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