Analysis of Microstructure and Textures on Batch Annealed IF Steel with Different Cold Reduction Ratio

2012 ◽  
Vol 429 ◽  
pp. 105-110
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Gong Ting Zhang
Keyword(s):  
Cold Rolling ◽  
Strain Ratio ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
If Steel ◽  
Plastic Strain Ratio ◽  
Batch Annealing ◽  
Hot Rolled ◽  
Strain Hardening Index ◽  
Tension Strength

Based on the experimental materials of hot rolled Ti+Nb-IF steels and Ti-IF steels produced in the industry, the effects of cold reduction ratios on its microstructures, mechanical properties and textures were investigated. The results show that experimental samples with different cold reduction ratios have been finished recrystallization by batch annealing at 720°C and soaking with 5h. As the cold reduction ratio increases, the grains will be refined and uniform, and the textures trends to be {111} texture. The {223}<110>, {111}, and {114}<110> textures appeared after cold rolling are inherited followed by annealing, whose intensities would be higher as the cold rolling ratio increased. And the textures will transform to the {223}<110>, {111}<110> and {114}<110> textures. With the increasing cold reduction ratio, the values of the yield strength Rp0.2 and tension strength Rm increase, but the Rp0.2 is almost about 100MPa. However, the strain hardening index n90 gradually decreases. The plastic strain ratio r90 which reaches the maximum with cold reduction ratio of 70% increases firstly and then decreases. Thus, the optimal cold reduction ratio of 70% to 80% is determined, which can obtain good deep drawing performances.

Effect of Cold Reduction Ratio on Deep-Drawing Performance of High Strength Ti-Nb-If Steel Sheets

2011 ◽  
Vol 415-417 ◽  
pp. 883-888
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao
Keyword(s):  
High Strength ◽  
Strain Ratio ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Strain Hardening Exponent ◽  
Strength Increase ◽  
If Steel ◽  
Plastic Strain Ratio ◽  
Steel Sheets ◽  
Hot Rolled

Hot rolled high strength Ti-Nb-IF steel sheet was used to study the effect of cold reduction ratio on the microstructures, mechanical properties and textures of experimental steel. The experimental results showed that the recrystallization has finished under different cold reduction ratio. The yield strength, tensile strength, elongation, the plastic strain ratio and strain hardening exponent were approximate 242MPa, 408MPa, 39.5%, 1.8, 0.26. With the cold reduction ratio increase, the textures strength increase, and the α textures have a trend with {111} texture. Therefore, the suggested the optimal cold reduction ratio is 75%, and it obtains optimally match of high strength and punching property.

Determination of Optimal Coiling Temperature and Cold Reduction Ratio of 260MPa Grade High Strength Nb-IF Steel

2011 ◽  
Vol 399-401 ◽  
pp. 148-151
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao
Keyword(s):  
High Strength ◽  
Strain Ratio ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Strain Hardening Exponent ◽  
If Steel ◽  
Coiling Temperature ◽  
Plastic Strain Ratio ◽  
N Value ◽  
R Value

Hot rolled 260MPa grade high strength Nb-IF steel sheet was used to study the effect of coiling temperature and cold reduction ratio on the microstructures and mechanical properties. The experimental results showed that the recrystallization has finished. Under 650°Ccoiling temperature and 75% cold reduction ratio, and under 600°C or 700°C coiling temperature and 65% cold reduction ratio, the plastic strain ratio r value and the strain hardening exponent n value were reached the maximum, and respectively, the r value was approximate 1.8, the n value was approximate 0.26. That obtains optimally match of high strength and punching property.

Effect of Cold Reduction Ratio and Annealing Temperature on Microstructure and Mechanical Property of Added Phosphorus High Strength Nb-IF Steel

2011 ◽  
Vol 117-119 ◽  
pp. 1792-1797
Author(s):  
Min Li Wang ◽  
Li Xiao ◽  
Zhi Wang Zheng
Keyword(s):  
Annealing Temperature ◽  
High Strength ◽  
Strain Ratio ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Strain Hardening Exponent ◽  
If Steel ◽  
Coiling Temperature ◽  
Plastic Strain Ratio ◽  
Percentage Yield

Hot rolled added phosphorus high strength IF steel was used to study the effect of cold reduction ratio and annealing temperature on the microstructures and mechanical properties of experimental steel. The experimental results showed that the recrystallization has finished under 840°C to 880°C annealing temperature followed 65% to 75% cold reduction ratio. Under 600°C coiling temperature, 840°C annealing temperature and 65% to 75% cold reduction ratio, the yield strength, tensile strength ,elongation percentage, yield point elongation, the plastic strain ratio and strain hardening exponent were approximate 240MPa, 410MPa, 36.0%, 1.6%, 0.26 and 1.9. Under 650°C coiling temperature, 860°C annealing temperature and 65% to 75% cold reduction ratio, and that were approximate 240MPa, 415MPa, 35.0%, 2.0%, 0.24 and 1.9. Under 700°C coiling temperature, 880°C annealing temperature and 65% cold reduction ratio, and that were approximate 190MPa, 380MPa, 35.0%, 0.8%, 0.26 and 2.0. Therefore, the suggested the optimal coiling temperature6 is 600°C, cold reduction ratio is 65% to 75%, annealing temperature is 840 °C, and it obtains optimally match of high strength and punching property.

Texture, Microstructure and Second-Phase Particles in a Ti+P Interstitial Free (IF) Steel

2005 ◽  
Vol 495-497 ◽  
pp. 423-428 ◽  
Author(s):  
Q.W. Jiang ◽  
E.B. Zhao ◽  
J.G. Zhang ◽  
Y. Chen ◽  
Gang Wang ◽  
...  
Keyword(s):  
Cold Rolling ◽  
High Strength ◽  
Strain Ratio ◽  
Warm Rolling ◽  
Second Phase ◽  
Rolled Sheet ◽  
Interstitial Free ◽  
If Steel ◽  
Plastic Strain Ratio ◽  
Second Phase Particles

The microstructure of Ti+P IF steel were studied after warm rolling, cold rolling and recrystallization using X-Ray, TEM and SEM. The results show that the characteristics of warm rolled sheet are the same as that of the cold rolled, but the texture displays different characteristics in the subsequent cold rolling and recrystallization because of the numerous second-phase particles. In this work, a Ti+P IF steel sheet with high strength and plastic strain ratio was obtained.

Effect of Cold Reduction Ratio and Annealing Temperature on Microstructure and Mechanical Property of 240MPa Grade High Strength if Steel

2011 ◽  
Vol 337 ◽  
pp. 23-28
Author(s):  
Min Li Wang ◽  
Li Xiao ◽  
Zhi Wang Zheng
Keyword(s):  
Annealing Temperature ◽  
High Strength ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Strain Hardening Exponent ◽  
If Steel ◽  
Coiling Temperature ◽  
Plastic Strain Ratio ◽  
Experimental Steel ◽  
High Strength If Steel

Hot rolled 240MPa grade high strength IF steel sheet was used to study the effect of cold reduction ratio and annealing temperature on the microstructures and mechanical properties of experimental steel. The experimental results showed that the recrystallization has finished under different annealing temperature followed 75% to 85% cold reduction ratio. To the experimental steel of high coiling temperature, The yield strength, tensile strength ,elongation percentage, yield point elongation, the plastic strain ratio and strain hardening exponent were approximate 260MPa, 445MPa, 37.5%, 2.14%, 0.25, 2.0. To the experimental steel of low coiling temperature, that were approximate 235MPa, 369MPa, 38.8%, 1.73%, 0.26, 2.1. Therefore, the suggested the optimal annealing temperature is 840 °C, cold reduction ratio is 75%, and it obtains optimally match of high strength and punching property.

Determination of Optimal Cold Reduction Ratio and Annealing Process of High Plastic Stain Ratio Structural Cold Rolling Steel Sheets

2011 ◽  
Vol 311-313 ◽  
pp. 489-493
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao
Keyword(s):  
Mechanical Properties ◽  
Cold Rolling ◽  
Structural Steel ◽  
Annealing Process ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Plastic Strain Ratio ◽  
Steel Sheets ◽  
R Value ◽  
High Plastic

Hot rolled high plastic stain ratio structural steel sheets was used to study the effect of cold reduction ratio and annealing process on the microstructures and mechanical properties. The results showed that the structural steel sheets was recrystallize finished after cold rolling follow different cold reduction ratio and batch annealing(annealing temperature 670°C and soaking time 5h) under experimental condition. When the cold reduction ratio was increased, the yield strength and tension strength increase, the elongation reduced followed different heating speed. The plastic strain ratio r value reached the maximum with cold reduction ratio of 50%, when the cold reduction ratio was increased, the r value was gradually reduced, However, the strain hardening exponent n value was gradually reduced. In the end, that suggested the optimal cold reduction ratio is 40% to 50%, and heating speed is 20°C/h, consequently that obtained good match of mechanical properties and punching property.

Effect of Coiling Temperature and Cold Reduction Ratio on Microstructure and Mechanical Property of Nb Microalloying Added Phosphorus High Strength IF Steel

2011 ◽  
Vol 393-395 ◽  
pp. 54-57
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao
Keyword(s):  
High Strength ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
If Steel ◽  
Coiling Temperature ◽  
Plastic Strain Ratio ◽  
N Value ◽  
Nb Microalloying ◽  
R Value ◽  
High Strength If Steel

Nb microalloying added phosphorus high strength IF steel was used to study the effect of coiling temperature and cold reduction ratio on the microstructures and mechanical properties. The experimental results showed that the recrystallization had finished. Under coiling temperature 650°C and cold reduction ratio 75%, and under coiling temperature 600°C or 700°C and cold reduction ratio 65%, the yield strength, tensile strength were lower , the elongation was higher. The plastic strain ratio r value and the strain hardening exponent n value were reached the higher value, respectively, the r value was approximate 1.8, and the n value was approximate 0.26. Therefore, the suggested the optimal coiling temperature is 700°C, cold reduction ratio is 65% to 75%, and it is optimal process of Nb microalloying added phosphorus high strength.

Determinition of Optimal Coiling Temperature and Cold Reduction Ratio of Adding P High Strength if Steel

2011 ◽  
Vol 213 ◽  
pp. 465-469
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao
Keyword(s):  
High Strength ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Strain Hardening Exponent ◽  
If Steel ◽  
Coiling Temperature ◽  
Plastic Strain Ratio ◽  
N Value ◽  
R Value ◽  
High Strength If Steel

Hot rolled adding P high strength IF steel sheet was used to study the effect of coiling temperature and cold reduction ratio on the microstructures , mechanical properties and textures of experimental steel. The experimental results showed that the recrystallization has finished after cold rolling followed diffrenent cold reduction ratio and coiling temperature was from 550 °C to 600 °C under experimental condition. When the cold reduction ratio was increased, the grain changed fine and uniformity under diffrenent coiling temperature; The yield strength, tensile strength and elongation percentage were approximate 160 MPa, 345 MPa and 35.0 % respectively, under coiling temperature 600 °C and diffrenent cold reduction ratio condition, the plastic strain ratio r value and the strain hardening exponent n value were reached the maximum, respectively, the r value was approximate 1.5, the n value was approximate 0.30. When the coiling temperature was increased, the {111}＜110＞ texture of α skeleton lines was stronger. Therefore, the suggested the optimal coiling temperature is 600 °C, cold reduction ratio was 60 % to 70 %, and it obtains optimally match of high strength and punching property.

Effect of Nb and V in the Development of Texture and Plastic Strain Ratio in Low Carbon Microalloyed Steels Produced by A.S.T. Technology

2005 ◽  
Vol 500-501 ◽  
pp. 279-286
Author(s):  
Carlo Mapelli ◽  
Roberto Venturini ◽  
Antonio Guindani
Keyword(s):  
Mechanical Properties ◽  
Strain Ratio ◽  
Tensile Tests ◽  
Microalloyed Steels ◽  
Low Carbon ◽  
Plastic Strain Ratio ◽  
Steel Technology ◽  
Back Scattering ◽  
Carbon Microalloyed ◽  
Hot Rolled

The effects of Nb and V on the anisotropy and textures featuring the hot rolled low carbon microalloyed steels produced by A.S.T. (Arvedi Steel Technology) have been studied as a function of the final coiling temperatute Tcoiling. Mechanical properties and r-values for twelve steels have been determined through tensile tests performed on three main different directions: 0°, 45°, 90° to the rolling one. The samples have been analysed by EBSD (Electron Back Scattering Diffraction) to identify the textures developed during the process. The relations among the chemical composition of the steels (i.e. C, N, Nb, V contents), the mechanical properties, the temperature during the coiling operations, the textures and the formability properties have been pointed out.

scholarly journals Microstructure and Texture of a Warmed Rolled IF Steel

2000 ◽  
Vol 34 (4) ◽  
pp. 243-253
Author(s):  
C. S. da Costa Viana ◽  
J. R. G. Matheus ◽  
A. M. Lopes ◽  
H. H. Aly El-Sharawy
Keyword(s):  
Cold Rolling ◽  
Plastic Anisotropy ◽  
Warm Rolling ◽  
Rolled Strip ◽  
If Steel ◽  
Steel Rolling ◽  
Orientation Image Microscopy ◽  
Back Scattering ◽  
Hot And Cold Rolling ◽  
Hot Rolled

Steel rolling within the temperature range intermediate between hot and cold rolling represents today a very economical and technically viable operation. The present work investigates the microstructure and the texture developed in a Ti microalloyed IF steel by rolling at 400°C and 600°C. Reductions of 40% and 60% were applied to a set of as hot rolled strip specimens part of which was subsequently annealed at 800°C for 5 minutes. Both the microstructure and the texture were examined by scanning electron microscopy. The texture was analysed by Electron Back Scattering Diffraction (EBSD) and Orientation Image Microscopy (OIM), and represented via the ODF method. The plastic anisotropy was also characterised. It was found that the textures developed by warm rolling are similar to those obtained by cold rolling, the intensities being also of comparable value. The microstructure is characterised by the presence of many shear banded grains whose amount was also quantified.

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