Research on the Precipitates in Warm-Rolled Ti-Bearing Interstitial-Free Steel Sheets

2006 ◽  
Vol 326-328 ◽  
pp. 1291-1294 ◽  
Author(s):  
Cai Nian Jing ◽  
Zuo Cheng Wang ◽  
Fu Tao Han ◽  
Wen Ping Zhang ◽  
Yan Hong Yi
Keyword(s):  
Texture Evolution ◽  
Steel Strip ◽  
High Strength ◽  
Warm Rolling ◽  
Interstitial Free ◽  
If Steel ◽  
Energy Dispersion Spectroscopy ◽  
Transmission Electron ◽  
Ferrite Region ◽  
Hot Rolled

Warm-rolling can save the production cost and extend the production kind of hot-rolled IF steel strip, the precipitates strongly influence the annealing process and texture evolution so as to the final mechanical properties of the production, very few studies has relate to the precipitates of IF steels warm-rolled in ferrite region. In present work, two Ti- IF steels were warm-rolled in ferrite region under different rolling parameters and the precipitates were investigated. Transmission electron microscopy (TEM) and Energy dispersion Spectroscopy (EDS) microanalysis were carried out on carbon extraction replicas, the characteristics such as morphology, type, amount and size of precipitates were analyzed. The results show that different type of precipitates were appeared in two steels, TiN, TiS, Ti4C2S2 and TiC were found in common Ti-IF steel, but in high strength Ti-IF steel, the amount of TiS, Ti4C2S2 was very few and FeTiP precipitates appeared, the type and morphology of precipitates were not affected by rolling parameters, however, the number and size of precipitates were changed. Finally, the effect of different P content on the change of precipitates was analyzed, the precipitating mechanism was also discussed.

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.

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.

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.

Influence of Boron on Mechanical Properties and Microstructures of Hot-Rolled Interstitial Free Steel

2005 ◽  
Vol 495-497 ◽  
pp. 537-542 ◽  
Author(s):  
S.I. Kim ◽  
Shi Hoon Choi ◽  
Yeon Chul Yoo
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Recrystallization Temperature ◽  
Interstitial Free ◽  
If Steel ◽  
Softening Behavior ◽  
Axial Tensile ◽  
Dynamic Softening ◽  
Work Hardening Rate ◽  
Hot Rolled

This paper examines an effect of boron (B) on dynamic softening behavior, mechanical properties and microstructures for Nb-Ti added high strength interstitial free (IF) steel. For this purpose, IF steels containing 0ppm B, 5ppm B and 30ppm B were chosen. Continuous cooling compression test was performed to investigate dynamic softening behavior. Mechanical properties and microstructures of pilot hot-rolled IF steel sheet were analyzed by uni-axial tensile test and electron back-scattered diffraction (EBSD). It was found that no-dynamic recrystallization temperature (Tndrx) which can be determined from the relationship between flow stress and temperature is a constant of 955oC for all IF steels. However, an addition of B into IF steels increases work hardening rate at the temperature below Tndrx. It was also verified that B retards phase transformation of austenite into ferrite. EBSD analysis revealed that absence of B induces fine ferrite grain size and many high angle grain boundaries.

Microtexture Study of Warm-Rolled High Strength Interstitial-Free (IF) Steel Sheets

2011 ◽  
Vol 682 ◽  
pp. 71-74
Author(s):  
Cai Nian Jing ◽  
Ming Gang Wang ◽  
Xi Jun Liu ◽  
Qi Zhong Tan ◽  
Zuo Cheng Wang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
High Strength ◽  
Interstitial Free ◽  
If Steel ◽  
Boundary Character ◽  
Deep Drawability ◽  
Grain Boundary Character ◽  
High Strength If Steel

Interstitial-free (IF) steel has excellent deep-drawability and was used widely in automotive industry. High strength IF-steel is that some phosphorus was put in common IF-steel to improve its strength without destroying the deep-drawability [1]. Microstructure and grain boundary character strongly affect the deep-drawability of high strength IF-steel, it is an obligatory task to test those characters. The technique of Electron Backscatter Diffraction (EBSD) can reveal the microtexture and detailed orientation distribution of grains from a single EBSD map, as a powerful instrument, EBSD was used widely in materials research from last decade [2]. Many researches have been focused on the texture evolution and recrystallization phenomena of high strength IF-steels [3,4], but the microtexture and grain boundary characters of warm-rolled high strength IF-steels was not fully investigated. The present study was aimed at researching the microtexture characters of a commercial high strength IF-steels under different warm-rolled temperature using EBSD technique, the microstructure and grain boundary character were analyzed systemically, and the relationship between the microstructure and deep-drawability was discussed.

scholarly journals Effect of Rare Earth Ce on Deep Stamping Properties of High-Strength Interstitial-Free Steel Containing Phosphorus

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1473
Author(s):  
Hao Wang ◽  
Yanping Bao ◽  
Chengyi Duan ◽  
Lu Lu ◽  
Yan Liu ◽  
...  
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Rare Earth ◽  
High Strength ◽  
Rolling Process ◽  
P Element ◽  
Second Phase ◽  
Strengthening Effect ◽  
Interstitial Free ◽  
If Steel

The influence of rare earth Ce on the deep stamping property of high-strength interstitial-free (IF) steel containing phosphorus was analyzed. After adding 120 kg ferrocerium alloy (Ce content is 10%) in the steel, the inclusion statistics and the two-dimensional morphology of the samples in the direction of 1/4 thickness of slab and each rolling process were observed and compared by scanning electron microscope (SEM). After the samples in each rolling process were treated by acid leaching, the three-dimensional morphology and components of the second phase precipitates were observed by SEM and energy dispersive spectrometer (EDS). The microstructure of the sample was observed by optical microscope, and the grain size was compared. Meanwhile, the content and strength of the favorable texture were analyzed by X-ray diffraction (XRD). Finally, the mechanical properties of the product were analyzed. The results showed that: (1) The combination of rare earth Ce with activity O and S in steel had lower Gibbs free energy, and it was easy to generate CeAlO3, Ce2O2S, and Ce2O3. The inclusions size was obviously reduced, but the number of inclusions was increased after adding rare earth. The morphology of inclusions changed from chain and strip to spherical. The size of rare earth inclusions was mostly about 2–5 μm, distributed and dispersed, and their elastic modulus was close to that of steel matrix, which was conducive to improving the structure continuity of steel. (2) The rare earth compound had a high melting point. As a heterogeneous nucleation point, the nucleation rate was increased and the solidification structure was refined. The grade of grain size of products was increased by 1.5 grades, which is helpful to improve the strength and plasticity of metal. (3) Rare earth Ce can inhibit the segregation of P element at the grain boundary and the precipitation of Fe(Nb+Ti)P phase. It can effectively increase the solid solution amount of P element in steel, improve the solid solution strengthening effect of P element in high-strength IF steel, and obtain a large proportion of {111} favorable texture, which is conducive to improving the stamping formability index r90 value.

Microstructure, Texture, Mechanical and Corrosion Performance of the Stainless Duplex Steel UNS S32205 Submitted to Warm Rolling

2018 ◽  
Vol 941 ◽  
pp. 118-123
Author(s):  
Dagoberto Brandão Santos ◽  
Raphael França Assumpção ◽  
Daniela Barçante Perasoli ◽  
Dalila Chaves Sicupira
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Warm Rolling ◽  
Optical Scanning ◽  
Transmission Electron ◽  
Duplex Steel ◽  
Hot Rolled ◽  
Chlorine Ion

The UNS S32205 duplex stainless steel was warm rolled at 600°C with 60 and 80% of thickness reduction. The microstructure was characterized by optical, scanning and transmission electron microscopy, X-ray diffractometry and EBSD. The corrosion resistance was evaluated by electrochemical behavior in the chlorine ion environment using potentiodynamic polarization measurements. The tensile strength reached 1185 MPa and 1328 MPa, after warm rolling with 60 and 80%, respectively. In steel as-supplied, hot rolled and annealed, the tensile strength was 774 MPa. Ferrite microtexture presented the α-fiber and the rotated cube component, while the austenite enhanced the brass, copper, and cube components to a lesser extent. The substructure was characterized by intense formation of tangles and forests of dislocations and discrete subgrains in the ferritic phase and by planar gliding of dislocations and formation of dense dislocations walls in the austenite. Despite the existence of a certain similarity among the values of pitting potentials obtained for all samples, the number of pits observed was higher in the as-received sample, followed by the samples with 60 and 80% reduction. These results draw attention to innovative routes in the industrial production of duplex stainless steel of this class, even considering ductility lost. Keywords: Warm rolling; Mechanical strength; Texture; Substructure; Corrosion resistance

Effect of Hot-Rolled Microstructure on the Recrystallization Texture of Cold-Rolled Non-Oriented Electrical Steel

2011 ◽  
Vol 298 ◽  
pp. 203-208 ◽  
Author(s):  
Zi Li Jin ◽  
Wei Li ◽  
Yi Ming Li
Keyword(s):  
Cold Rolling ◽  
Electrical Steel ◽  
Texture Evolution ◽  
Steel Strip ◽  
Silicon Steel ◽  
Grain Structure ◽  
Recrystallization Annealing ◽  
Rolled Sheet ◽  
Cold Rolled ◽  
Hot Rolled

With the help of orientation distribution function (ODF) analysis, experiments of different hot band grain microstructure 0.33% silicon steel were cold-rolled and annealed in the laboratory，to study the effect of the microstructure hot-rolled steel strip for cold rolled non-oriented silicon steel microstructure and texture of recrystallization annealing. The results show that hot rolled microstructure on cold rolled Non-Oriented Electrical Steel cold-rolled sheet evolution of texture and recrystallization have important influence, the quiaxed grain structure of steel by cold rolling and recrystallization annealing, the recrystallization speed than the fiber grain-based mixed crystals recrystallization fast , With the equiaxed grains made of cold rolled silicon steel after annealing the {110}<UVW> texture components was enhanced and {100}<uwv> texture components weakened. Different microstructure condition prior to cold rolling in the recrystallization annealing process the texture evolution has the obvious difference, the equiaxial grain steel belt cold rolling and annealing, has the strong crystal orientation. This shows that the equiaxed grain when hot microstructure is detrimental to the magnetic properties of cold-rolled non-oriented silicon steel to improve and increase.

scholarly journals Effect of Isothermal Treatment on Microstructure and Mechanical Properties of Cold-Deformed IF Steel

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Jose Luis Reyes Barragan ◽  
Roberto Ademar Rodriguez Diaz ◽  
Maria Luisa Ojeda Martinez ◽  
Silvia Gaona Jimenez ◽  
Julio Alberto Juarez Islas
Keyword(s):  
Mechanical Properties ◽  
Graphical Model ◽  
Tensile Tests ◽  
Ultimate Tensile Stress ◽  
Isothermal Treatment ◽  
Interstitial Free ◽  
If Steel ◽  
Secondary Refining ◽  
Stress And Deformation ◽  
Hot Rolled

In this study, we investigated the recrystallisation kinetics of Ti-stabilised interstitial-free (IF) steel manufactured by the Mexican steel industry through the route of electric arc furnace with vacuum degassing, secondary refining, and subsequent continuous casting. The IF steel was hot-rolled at 950°C and then cold-rolled until deformation of 94% was attained, followed by recrystallisation at different times at a constant temperature of 780°C. In addition, the mechanical properties of the IF steel were assessed as a function of recrystallisation time. The results obtained from the mechanical property tests were presented in the form of plots of microhardness, yield strength, ultimate tensile stress, and deformation percent as functions of the recrystallised fraction with an indirect dependence on recrystallisation time. A graphical model of the recrystallisation behaviour showed the evolution of the microstructure, including phase transformations, hardness, and the mechanical properties determined from the tensile tests. In view of subsequent recovery and recrystallisation, stored energy analysis derived from the strain induced by deformation was presented. Furthermore, we determined the precipitates formed in the different processing stages of IF steel.

Sign in / Sign up

Export Citation Format

Share Document