Study of Recrystallization and Phase Transformation in a Cold-Rolled Dual-Phase Steel: Influence of Temperature and Heating Rate during First Annealing Stages

2011 ◽  
Vol 702-703 ◽  
pp. 818-821 ◽  
Author(s):  
Carla Barbatti ◽  
Patricia Romano Triguero ◽  
Stefan Van Bohemen ◽  
Steven Celotto ◽  
Dave N. Hanlon
Keyword(s):  
Heating Rate ◽  
Dual Phase Steel ◽  
Dual Phase ◽  
Low Carbon ◽  
Dp Steel ◽  
Influence Of Temperature ◽  
Individual Contributions ◽  
Cold Rolled ◽  
Dp Steels ◽  
The Individual

The effect of heating path and heating rate on the microstructure and texture development in cold-rolled continuously annealed DP steel was studied by SEM and EBSD. A methodology to separate the individual phases present in mixed microstructures, and thus to enable quantification of the individual contributions to the bulk texture has been applied. It was observed that a higher heating rate may promote strengthening of {111} textures in DP steels as observed in low carbon grades.

scholarly journals Microstructural Characterization and Corrosion-Resistance Behavior of Dual-Phase Steels Compared to Conventional Rebar

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1068
Author(s):  
Hany S. Abdo ◽  
Asiful H. Seikh ◽  
Biplab Baran Mandal ◽  
Jabair A. Mohammed ◽  
Sameh A. Ragab ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Galvanic Corrosion ◽  
Microstructural Characterization ◽  
Carbon Steels ◽  
Dual Phase ◽  
Low Carbon ◽  
Dp Steel ◽  
Dp Steels ◽  
Superior Corrosion Resistance ◽  
Corrosive Environments

Dual-phase (DP) steels consist of a ferritic matrix dispersed with some percentage of martensite, which gives the material a good combination of strength and ductility, along with the capacity to absorb energy and enhanced corrosion protection properties. The purpose of this work was to study the microstructural and corrosion behavior (mainly pitting and galvanic corrosion) of DP steel compared with that of conventional rebar. To obtain DP steel, low-carbon steels were heat-treated at 950 °C for 1 h and then intercritically annealed at 771 °C for 75 min, followed by quenching in ice-brine water. The corrosion rates of DP steel and standard rebar were then measured in different pore solutions. Macro- and microhardness tests were performed for both steels. It was found that DP steels exhibited a superior corrosion resistance and strength compared to standard rebar. The reported results show that DP steels are a good candidate for concrete reinforcement, especially in aggressive and corrosive environments.

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.

scholarly journals Spheroidization heat treatment and intercritical annealing of low carbon steel

2019 ◽  
Vol 55 (3) ◽  
pp. 405-411 ◽  
Author(s):  
Z. Nasiri ◽  
H. Mirzadeh
Keyword(s):  
Carbon Steel ◽  
Intercritical Annealing ◽  
Low Carbon Steel ◽  
Dual Phase ◽  
Low Carbon ◽  
Dp Steel ◽  
Martensitic Microstructure ◽  
Uniform Dispersion ◽  
Dp Steels ◽  
Carbide Particles

Spheroidization annealing of low carbon steel and its effects on the microstructure and mechanical properties of dual phase (DP) steel were studied. It was revealed that the reduction in strength and hardness of the quenched martensitic microstructure was much more pronounced compared to the fully annealed ferritic-pearlitic banded microstructure with spheroidizing time. This was related to the confinement of spheroidized carbide particles to distinct bands in the latter, and the uniform dispersion of carbides and high-temperature tempering of martensite in the former. During intercritical annealing of the spheroidized microstructures, the tendency to obtain martensite particles as discrete islands was observed. This, in turn, resulted in an inferior strength-ductility balance compared to the DP steel obtained from the intercritical annealing of martensite, which negated the usefulness of the spheroidized microstructures as the initial microstructures for the processing of DP steels.

scholarly journals Microstructure and Mechanical Properties of a Cold-Rolled Ultrafine-Grained Dual-Phase Steel

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1399 ◽  
Author(s):  
Zhiyi Pan ◽  
Bo Gao ◽  
Qingquan Lai ◽  
Xuefei Chen ◽  
Yang Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dual Phase Steel ◽  
Uniform Elongation ◽  
Processing Route ◽  
Dual Phase ◽  
Dp Steel ◽  
Ultrafine Grained ◽  
Superior Mechanical Properties ◽  
Cold Rolled ◽  
New Processing

A new processing route to produce Ultrafine-Grained Dual-Phase steel has been proposed, involving cold-rolling and subsequent intercritical annealing of a fibrous ferrite–martensite starting structure. Ultrafine-grained DP (UFG-DP) steel with an average ferrite grain size of about ~2.7 μm and an average martensite island size of ~2.9 μm was achieved. Tensile testing revealed superior mechanical properties (the ultimate tensile strength of 1267 MPa and uniform elongation of 8.2%) for the new DP steel in comparison with the fibrous DP steels. The superior mechanical properties are attributed to the influence of microstructure refinement on the work-hardening and fracture behavior.

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.

High Silicon Addition in 780 MPa Cold-Rolled Dual Phase Steel for Carbon Reduction and Plastic Reinforce

2014 ◽  
Vol 1004-1005 ◽  
pp. 183-187
Author(s):  
Shuang Kuang ◽  
Xiu Mei Qi
Keyword(s):  
Mechanical Properties ◽  
Dual Phase Steel ◽  
Transformation Kinetic ◽  
Low Carbon ◽  
Dp Steel ◽  
Carbon Reduction ◽  
Cold Rolled ◽  
Intercritical Region ◽  
High Silicon

Two types of DP steels which contain high carbon and high silicon respectively were produced on industrial production line. The microstructures and mechanical properties were investigated. Based on the thermodynamics and kinetic analyses, the intercritical austenization was researched. The results show that the high silicon and low carbon composition used to DP steel can avoid martensite band structure and decrease the martensite fraction, which will improve the elongation and work hardening ability. Phase transformation kinetic analysis indicates that high silicon content can make manganese enrich in austenite and stabilize austenite in intercritical region. Assisted by the strengthening role of silicon in austenite, the mechanical properties of high silicon and low carbon DP can fully meet the standard.

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