The Effects of Heating Rate and Cold Work on the Development of Dual-Phase Steel Microstructures

2014 ◽  
Vol 922 ◽  
pp. 755-760
Author(s):  
L.S. Thomas ◽  
David K. Matlock ◽  
John G. Speer
Keyword(s):  
Heating Rate ◽  
Dual Phase Steel ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
Carbon Steels ◽  
Dual Phase ◽  
Low Carbon ◽  
Heating Rates ◽  
Contributing Factors ◽  
Transformation Temperatures

The effects of heating rate and prior cold work on the development of dual-phase steel microstructures in three low carbon steels were evaluated with samples processed on a Gleeble 3500 thermomechanical processing simulator. The nominally 0.2 wt pct carbon steels included a plain carbon steel and modified alloys incorporating higher manganese contents, boron additions, and microalloy additions. Each alloy was prepared with two different cold rolled reductions. Heating rates from 1 to 1000 oC/s were selected to span the rates typically experienced in conventional furnace heat treating up to rates for induction heating. Critical transformation temperatures were obtained from dilatometric curves. Dual-Phase microstructures after heat treatment with different heating rates were compared. Transformation temperatures decreased with an increase in cold work and increased with an increase in heating rate. The steels with higher manganese and carbon additions exhibited lower Ac3 values across all heating rates and the steels with higher silicon higher Ac1 temperatures across all heating rates. Ac1 increased less than Ac3 with increasing heating rate. The increase in transformation temperatures between 100 and 1000 °C/s was smaller than values exhibited over other increments in heating rate, and decreased in one steel; contributing factors were identified for this behavior.

Effect of manganese bands on austenite formation of low carbon steels in dual phase steel manufacture

2020 ◽  
Author(s):  
Bharath Bandi ◽  
Joost van Krevel ◽  
Sukalpan Nandi ◽  
Zulfiqar Husain ◽  
Prakash Srirangam
Keyword(s):  
Dual Phase Steel ◽  
Carbon Steels ◽  
Austenite Formation ◽  
Dual Phase ◽  
Low Carbon ◽  
Low Carbon Steels

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.

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.

Microstructural Control of Dual Phase Structure Formed by Partial Reversion from Cold-Deformed Martensite

2013 ◽  
Vol 753 ◽  
pp. 191-194 ◽  
Author(s):  
Nobuo Nakada ◽  
Yusuke Arakawa ◽  
Kyo Sun Park ◽  
Toshihiro Tsuchiyama ◽  
Setsuo Takaki
Keyword(s):  
Heating Rate ◽  
Microstructural Development ◽  
Dual Phase ◽  
Low Carbon ◽  
Heating Rates ◽  
Dp Structure ◽  
The Matrix ◽  
Fresh Martensite ◽  
Rolling Rate ◽  
Partial Reversion

Dual phase (DP) structure formed by partial reversion from cold-deformed martensite was investigated to improve mechanical property of DP steel by grain refinement strengthening. A low carbon martensitic steel (0.15C-1.0Mn) was cold-rolled and then held just above A1 temperature to partially form austenite. In particular, the conditions of cold-rolling rate (0~60% reduction in thickness) and heating rate (0.083 and 100 K/s) were varied to understand their effects on the microstructural development of DP structure. Although the recrystallization has never occurred in undeformed martensite, cold-deformed martensite was more easily recrystallized before reversion with increasing rolling rate and lowering heating rate. Then, the matrix of DP structure was changed from tempered martensite to recrystallized ferrite, which had a large influence on the distribution of fresh martensite transformed from reversed austenite. The higher rolling and heating rates resulted in the finer DP structure, leading to a large improvement in strength level.

MITTAL DI-FORM T700, HF80Y100T

Alloy Digest ◽  
2007 ◽  
Vol 56 (2) ◽  
Keyword(s):  
Automotive Industry ◽  
High Strength ◽  
Martensite Phase ◽  
Carbon Steels ◽  
Ferrite Phase ◽  
Dual Phase ◽  
Low Carbon ◽  
Advanced High Strength Steel ◽  
Dp Steels ◽  
Soft Ferrite

Abstract MITTAL DI-FORM T700 and HF80Y100T are low-carbon steels with a manganese and silicon composition. Dual-phase (DP) steels are one of the important advanced high-strength steel (AHSS) products developed for the automotive industry. Their microstructure typically consists of a soft ferrite phase with dispersed islands of a hard martensite phase. The martensite phase is substantially stronger than the ferrite phase. The DI-FORM grades exhibit low yield-to-tensile strengths, and the numeric designation in the name corresponds to the tensile strength. This datasheet provides information on microstructure and tensile properties as well as deformation and fatigue. It also includes information on forming. Filing Code: SA-561. Producer or source: Mittal Steel USA Flat Products.

Effect of Prior Cold Work on Dual Phase Steel

1985 ◽  
pp. 539-544
Author(s):  
A.A. Hussein ◽  
L.I. El-Menawati ◽  
Z.M. El-Bradie
Keyword(s):  
Dual Phase Steel ◽  
Cold Work ◽  
Dual Phase ◽  
Prior Cold Work
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