Effect of Continuous Annealing Parameters on the Microstructure and Magnetic Property of Cold Rolled Dual Phase Steel

2012 ◽  
Vol 476-478 ◽  
pp. 241-247 ◽  
Author(s):  
Li Gao ◽  
Qiu Hong Song ◽  
Jun Ting Yuan
Keyword(s):  
Magnetic Properties ◽  
Magnetic Property ◽  
Dual Phase Steel ◽  
Volume Fraction ◽  
Annealing Process ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Quenching Temperature ◽  
Dp Steel ◽  
Cold Rolled

The effect of continuous annealing parameters on the microstructure and magnetic property of cold rolled dual phase steel (DP steel) are investigated. Correlations of microstructure, magnetic properties and continuous annealing parameters are revealed. The mechanism of the magnetic property varying with continuous annealing process is also discussed. The results show that recrystallization is almost completed when heating to 740°C. For the DP steel soaked in the range of 770°C-830°C and quenched in different temperature, the TEM results indicate its microstructure mainly consists of the ferrite and martensite phase. The martensite volume fraction increases gradually with increasing the soaking and quenching temperature. It is found that magnetic properties of dual phase steel are very sensitive to continuous annealing process. With rising soaking and quenching temperature, the coercivity and hysteresis loss increase obviously, whereas the maximum permeability and the remanent induction tend to decrease.

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.

Deformation Behaviour of Martensite in a Low-Carbon Dual-Phase Steel

2006 ◽  
Vol 15-17 ◽  
pp. 774-779 ◽  
Author(s):  
M. Mazinani ◽  
Warren J. Poole
Keyword(s):  
Dual Phase Steel ◽  
Volume Fraction ◽  
Deformation Behaviour ◽  
Dual Phase ◽  
Low Carbon ◽  
Heating Rates ◽  
Dp Steel ◽  
Martensite Content ◽  
High Heating ◽  
Different Temperatures

The deformation behaviour of martensite and its effect on tensile properties of a lowcarbon dual-phase (DP) steel were investigated. DP steel samples with different martensite contents and morphologies were produced after intercritical annealing at different temperatures using low and high heating rates. Two distinct martensite morphologies were obtained for low and high heating rates. The investigated steel showed the unusual results that the true fracture stress and strain were found to increase with the martensite volume fraction. The plastic deformation of martensite was considered to be responsible for these results. Experimentally, it was observed that the martensite in DP steels with greater than 25-30% martensite can deform plastically during tensile straining. Finally, the effect of tempering on the martensite plasticity was also evaluated. It was found that the tempering process and an increase in the martensite content have a similar effect on promoting martensite plasticity.

The Influence of Quenching Temperature on the Mechanical Properties of a Dual-Phase Steel with 0.094% C and 0.53% Mn

2015 ◽  
Vol 808 ◽  
pp. 28-33 ◽  
Author(s):  
Constantin Dulucheanu ◽  
Nicolai Bancescu ◽  
Traian Severin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Dual Phase Steel ◽  
Volume Fraction ◽  
Total Elongation ◽  
Metallographic Analysis ◽  
Dual Phase ◽  
Quenching Temperature ◽  
Offset Yield Strength ◽  
Martensite Structure

In this article, the authors have analysed the influence of quenching temperature (TQ) on the mechanical properties of a dual-phase steel with 0.094 % C and 0.53% Mn. In order to obtain a ferrite-martensite structure, specimens of this material have been the subjected to intercritical quenching that consisted of heating at 750, 770, 790, 810 and 830 °C, maintaining for 30 minutes and cooling in water. These specimens have then been subjected to metallographic analysis and tensile test in order to determine the volume fraction of martensite (VM) in the structure, ultimate tensile strength (Rm), the 0.2% offset yield strength (Rp0.2), the total elongation (A5) and the Rp0.2/Rm ratio.

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