On the mechanism of Mn partitioning during intercritical annealing in medium Mn steels

The final microstructure of DP and TRIP assisted steels can evolve after hot working (hot rolling) or during post heat treatment process. In the formation of the final structure a number of different technological parameters have important role, e.g. finishing temperature of rolling, cooling rates, temperature of intercritical annealing, etc. As a result of the individual factors and their combinations a lot of production technology routes are feasible. The effect of the different combinations of these technological parameters on the microstructure can be mapped by a special Jominy end-quench test (so called intercritical Jominy end-quench test) described in this paper. Unlike the traditional Jominy test, in this case there is a partial austenizing between A1 and A3 temperatures which results in a given amount of ferrite in the microstructure before quenching. The amount of ferrite depends on the temperature. In some cases the quenching process was interrupted for a given period of time in order to model the cooling process on the run-out table. During cooling each point of the Jominy specimen has a different cooling rate, so the effect of cooling rate on the microstructure can be evaluated along the length of the specimen.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.313-314.693 ◽

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.

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On the Selection of the Optimal Intercritical Annealing Temperature for Medium Mn TRIP Steel

Metallurgical and Materials Transactions A ◽

10.1007/s11661-013-1860-2 ◽

2013 ◽

Vol 44 (11) ◽

pp. 5018-5024 ◽

Cited By ~ 134

Author(s):

Seawoong Lee ◽

Bruno C. De Cooman

Keyword(s):

Trip Steel ◽

Annealing Temperature ◽

Intercritical Annealing ◽

Intercritical Annealing Temperature ◽

Selection Of

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Influence of Critical Carbide Dissolution Temperature during Intercritical Annealing on Hardenability of Austenite and Mechanical Properties of DP-980 Steels

ISIJ International ◽

10.2355/isijinternational.51.969 ◽

2011 ◽

Vol 51 (6) ◽

pp. 969-974 ◽

Cited By ~ 12

Author(s):

Calixto Isaac Garcia ◽

Kengun Cho ◽

Konstantin Redkin ◽

Anthony John Deardo ◽

Susheng Tan ◽

...

Keyword(s):

Mechanical Properties ◽

Intercritical Annealing ◽

Dissolution Temperature ◽

Carbide Dissolution

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Formation of Austenite During Intercritical Annealing of Dual-Phase Steels

Metallurgical and Materials Transactions A ◽

10.1007/bf02643686 ◽

1981 ◽

Vol 12 (8) ◽

pp. 1419-1428 ◽

Cited By ~ 382

Author(s):

G. R. Speich ◽

V. A. Demarest ◽

R. L. Miller

Keyword(s):

Intercritical Annealing ◽

Dual Phase ◽

Dual Phase Steels

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Influence of the austenitic rolling temperature on the microstructure of a TRIP steel before intercritical annealing

Journal of Materials Science ◽

10.1007/s10853-009-3405-z ◽

2009 ◽

Vol 44 (12) ◽

pp. 3057-3060 ◽

Cited By ~ 1

Author(s):

C. N. dos Santos ◽

A. G. Vieira ◽

A. S. Paula ◽

C. S. C. Viana

Keyword(s):

Trip Steel ◽

Intercritical Annealing ◽

Rolling Temperature

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Effect of Martensite Morphologies on Corrosion in 5% H2SO4 Solution of Borided X70 Dual Phase Steel

Annales de Chimie Science des Matériaux ◽

10.18280/acsm.450109 ◽

2021 ◽

Vol 45 (1) ◽

pp. 69-74

Author(s):

Tassi Hocine ◽

Zidelmel Sami ◽

Allaoui Omar

Keyword(s):

Corrosion Resistance ◽

Dual Phase Steel ◽

Annealing Temperature ◽

Intercritical Annealing ◽

Ferrite Matrix ◽

Dual Phase ◽

H2so4 Solution ◽

Dp Steel ◽

Direct Quenching ◽

Step Quenching

In the present investigation, some electrochemical properties of dual phase X70 steels with different martensite morphologies which have undergone boriding were studied. To obtain a variety of martensite morphologies, Direct Quenching (DQ), Intermediate Quenching (IQ) and Step Quenching (SQ) heat treatments were applied at an intercritical annealing temperature (IAT) of 760℃. The treatment (DQ) allowed the formation of fine martensite evenly distributed in the ferrite matrix. (IQ) treatment showed the formation of martensite along the ferrite / ferrite grain boundaries. In contrast, treatment (SQ) induced the formation of a banded morphology of martensite and ferrite. The realization of borides on X70 (DP) steel was carried out in a powder mixture containing 5% of B4C as source of boron, 5% of NaBF4 as activator and 90% of SiC as diluent at 950℃ for a period of time from 4 h. The corrosion behavior of X70 (DP) steel has been explored by the Tafel extrapolation method in a 5 wt. % H2SO4 solution. The corrosion resistance of steel which has undergone boriding (BDP) is higher than that of steel which has not undergone it (DP).

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