Effects of Continuous Annealing Process Parameters on the Microstructure and Mechanical Properties of Dual Phase Steel

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.867.45 ◽

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.

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

Archives of Metallurgy and Materials ◽

10.2478/amm-2014-0140 ◽

2014 ◽

Vol 59 (2) ◽

pp. 821-824 ◽

Cited By ~ 3

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.

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Influence of annealing process on microstructure and mechanical properties of C-Mn dual phase steel

Metallic Materials ◽

10.4149/km_2015_5_341 ◽

2016 ◽

Vol 52 (05) ◽

pp. 341-348

Author(s):

M. SEBEK ◽

P. HORŇAK ◽

S. LONGAUER ◽

P. ZIMOVČÁK ◽

P. ZÁHUMENSKÝ

Keyword(s):

Mechanical Properties ◽

Dual Phase Steel ◽

Annealing Process ◽

Dual Phase ◽

Microstructure And Mechanical Properties

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Influence of Continuous Annealing Conditions on the Microstructure and Mechanical Properties of a C-Mn Dual Phase Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.3479 ◽

2010 ◽

Vol 638-642 ◽

pp. 3479-3484 ◽

Cited By ~ 1

Author(s):

Roberta O. Rocha ◽

Tulio M.F. Melo ◽

Dagoberto Brandao Santos

Keyword(s):

Mechanical Properties ◽

Microstructural Analysis ◽

Tensile Tests ◽

Recrystallization Temperature ◽

Continuous Annealing ◽

Dual Phase ◽

Heating Rates ◽

Microstructure And Mechanical Properties ◽

Annealing Cycle ◽

Soaking Temperature

The influence of continuous annealing variables on the microstructure and mechanical properties of a C-Mn Dual Phase (DP) steel was studied. The annealing cycles were simulated using a Gleeble machine. Some specimens were quenched at different stages of the annealing cycle in order to evaluate the microstructural evolution during the annealing process. Tensile tests and microstrutural analysis were carried out. The results showed that high heating rates increased the final recrystallization temperature and as a consequence the microstructure obtained was refined. Austenite grain nucleation and growth were also influenced by the heating rates. Soaking temperature was the most influent variable on the mechanical properties, i. e., the yield strength increased and the tensile strength decreased with an increase in the soaking temperature. Microstructural analysis showed that not only martensite, but also bainite and martensite-retained autenite constituent (MA) were formed. Undissolved carbides were also detected by transmission electron microscopy.

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