Research of the Continuous Annealing Process to Eliminate the "Band" Feature of Dual Phase Steels

2016 ◽  
Vol 867 ◽  
pp. 45-49
Author(s):  
Ji Lin Chen ◽  
Guo Hui Zhu ◽  
Jian Zhang ◽  
Yong Gang Liu ◽  
Hong Bo Pan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Dual Phase Steel ◽  
Annealing Temperature ◽  
Annealing Process ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Dual Phase Steels ◽  
Steel Sheets ◽  
Scanning Electron

A new continuous annealing process which can eliminate the "band" feature of dual phase steels has been designed. The sheets were annealed in MULTIPAS annealing simulator under variation of annealing temperature. The microstructure evolution of dual-phase steel sheets annealed at intercritical temperatures, were analyzed by optical microscopy and scanning electron microscopy. And the properties were compared with the sheets which annealed by the existing annealing process. The results show that: the "band" feature of dual-phase steel can be effectively eliminated by the optimizing continuous annealing process,and the mechanical properties are improved.

scholarly journals Effect of Annealing Process on the Mechanical Properties of X70 Pipeline Steel

2018 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Teng-wei Zhu ◽  
Cheng-liang Miao ◽  
Zheng Cheng ◽  
Zhipeng Wang ◽  
Yang Cui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Annealing Temperature ◽  
Pipeline Steel ◽  
Annealing Process ◽  
X70 Pipeline Steel ◽  
Grain Sizes ◽  
Scanning Electron

The influence of the mechanical properties of X70 pipeline steel under different annealing temperature was studied. The corresponding microstructure was investigated by the Field Emission Scanning Electron Microscopy. The results showed that the yield strength and the tensile strength both experienced from rise to decline with the increase of annealing temperature. The grain sizes were coarse and a large amount of cementite precipitated due to preserving temperature above 550 °, which induced matrix fragmentation and deteriorate the -10 ° DWTT Toughness. There were little changes on the microstructure and mechanical properties when the annealing temperature was under 500 °.

Microstructure Evolution and Mechanical Properties of 780 MPa Hot Dip Galvanized Dual-Phase Steel

2010 ◽  
Vol 146-147 ◽  
pp. 1331-1335 ◽  
Author(s):  
Guo Bin Li ◽  
Zheng Zhi Zhao ◽  
Di Tang
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Dual Phase Steel ◽  
Total Elongation ◽  
Annealing Process ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Dp Steel ◽  
Gleeble 3500 ◽  
Soaking Temperature

The microstructure evolution of 780 MPa hot dip galvanized dual-phase (DP) steel at heating stages of the annealing process was analyzed using a Gleeble−3500 thermal/mechanical simulator. A multifunction continuous annealing simulator was employed to investigate the effect of annealing process on microstructure and mechanical properties of hot dip galvanized DP steel. The experimental results show that ferrite recovery and recrystallization, pearlite dissolution and austenite nucleation and growth take place in the annealing process of hot dip galvanized DP steel. The hardenability can be significantly improved by trace addition of vanadium. When the soaking temperature reaches 780 °C, the tensile strength and total elongation of DP steel can reach 785MPa and 15%, respectively. The microstructure of DP steel mainly consists of a mixture of ferrite and martensite.

scholarly journals Microstructure Evolution and Mechanical Properties of C-Mn Cold Rolled Dual Phase Steel after Continuous Annealing Process in Laboratory Conditions

2014 ◽  
Vol 59 (2) ◽  
pp. 821-824 ◽  
Author(s):  
M. Šebek ◽  
P. Horňak ◽  
P. Zimovčák ◽  
S. Longauer
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Dual Phase Steel ◽  
Annealing Process ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Laboratory Conditions ◽  
Cold Rolled ◽  
Intercritical Region ◽  
Evolution Of Microstructure

Abstract The article deals with the influence of annealing parameters on evolution of microstructure and mechanical properties of dual phase steel. Dual phase steel was annealed in laboratory conditions according to the three chosen cycles of annealing: into intercritical region (780°C), into austenite region (920°C) and into austenite region (920°C) by subsequently cooling into intercritical region (780°C) with the hold at the temperature of 495°C. Simulation of annealing regimes by thermo-mechanical simulator Gleeble was done. The obtained microstructure consists from three phases: ferritic matrix, martensite and martensite/ bainite grains. For the microstructure identification the TEM and nanoindentation experiments were performed.

Effect of Intercritical Annealing Temperature on Development of Cold Rolled Dual Phase Steel from Q345 Steel

2013 ◽  
Vol 313-314 ◽  
pp. 693-696
Author(s):  
Ji Yuan Liu ◽  
Fu Xian Zhu ◽  
Shi Cheng Ma
Keyword(s):  
Dual Phase Steel ◽  
Annealing Temperature ◽  
Simulation Experiment ◽  
Intercritical Annealing ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Automotive Applications ◽  
Treatment Procedure ◽  
Annealing Temperatures ◽  
Cold Rolled

Cold rolled dual phase steel was developed from Q345 steel by heat treatment procedure for automotive applications. The ultimate tensile strength was improved about 100MPa higher than the traditional cold-rolled Q345 steel in the continuous annealing simulation experiment. The microstructure presented varied characteristics in different intercritical annealing temperatures; mechanical properties were changed correspondingly as well. The chief discussions are focus on the recrystallization, hardenability of austenite and martensite transformation in the experiment.

EBSD Study of Substructure and Texture Formation in Dual-Phase Steel Sheets for Semi-Finished Products

2010 ◽  
Vol 160 ◽  
pp. 251-256 ◽  
Author(s):  
M. Masimov ◽  
N. Peranio ◽  
B. Springub ◽  
Franz Roters ◽  
Dierk Raabe
Keyword(s):  
Cold Rolling ◽  
Annealing Temperature ◽  
Texture Evolution ◽  
Industrial Process ◽  
Dual Phase ◽  
Technological Parameters ◽  
Dual Phase Steels ◽  
Final Annealing ◽  
Steel Sheets ◽  
Different Temperatures

Using SEM/EBSD the substructure and texture evolution in dual phase steels in the first steps of the process chain, i.e. hot rolling, cold rolling, and following annealing were characterized. In order to obtain dual phase steels with high ductility and high tensile strength an industrial process was reproduced by cold rolling of industrially hot rolled steel sheets of a thickness of 3.75 mm with ferrite and pearlite morphology down to a thickness of 1.75 mm and finally annealing at different temperatures. Such technique allows a compilation of ferrite and martensite morphology typical for dual phase steels. Due to the competition between recovery, recrystallization and phase trans-formation during annealing a variety of ferrite martensite morphologies was produced by promoting one of the mechanisms through the variation of technological parameters such as heating rate, intercritical annealing temperature, annealing time, cooling rate and the final annealing temperature. Annealing induced changes of the mechanical properties were determined by hardness measurements and are discussed on the basis of the results of the substructure investigations.

Research on the Mechanism of Aging of Dual Phase Steel Produced by Continuous Annealing

2010 ◽  
Vol 97-101 ◽  
pp. 556-559 ◽  
Author(s):  
Hao Yu ◽  
Yong Lin Kang
Keyword(s):  
Electron Microscopy ◽  
Strain Aging ◽  
Room Temperature ◽  
Dual Phase Steel ◽  
High Strain ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Transmission Electron ◽  
Aging Resistance ◽  
And Diffusion

The microstructure and properties of aging at room temperature of dual phase steel produced by continuous annealing were investigated by using mechanical property test, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In order to know the mechanisms of aging of dual phase steel produced by this process, the relative theories of dissolution and diffusion of interstitials, dislocation and precipitation are proposed and discussed. From analysis, the results showed that dual phase steel produced by continuous annealing had high strain aging resistance after overaging.

Influence of Inhibition Layer on Adhesion of a Galvanized High Al Dual Phase Steel

2011 ◽  
Vol 295-297 ◽  
pp. 1669-1674
Author(s):  
Zhao Jun Deng ◽  
Jing Liu ◽  
Zhi Hong Lu ◽  
Hui Wang ◽  
Cheng Jiang Lin
Keyword(s):  
Electron Microscopy ◽  
Manganese Oxides ◽  
Dual Phase Steel ◽  
Steel Substrate ◽  
Dual Phase ◽  
Inhibition Layer ◽  
Good Adhesion ◽  
Transmission Electron ◽  
Mn Oxides ◽  
Scanning Electron

The morphology of inhibition layer and adhesion of Zn coating about a 600MPa grade high Al dual phase steel were studied by grow discharge spectrometry (GDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the inhibition layer is mainly composed of Fe2Al5-xZnx particles with a size of 0.5~1μm, and the adhesion is directly related to the density of the inhibition layer, the denser the inhibition layer, the better the adhesion. It is found: for the samples with good adhesion that besides the Fe2Al5-xZnx particles, there are also some small spherical Al-Mn oxides particles in sizes from 30 to 100nm uniformly distributed in the inhibition layer; for the samples with bad adhesion, the steel substrate is not fully covered by Fe2Al5-xZnx particles and large amount manganese oxides are detected at the non-covered positions.

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