Effect of Mo on Transformation, Microstructure and Property of Hot-Rolled DP600 Steel

2015 ◽  
Vol 817 ◽  
pp. 560-564
Author(s):  
Le Yu Zhou ◽  
Tian Hao Cui ◽  
Bo Jiang ◽  
Chao Lei Zhang ◽  
Jian Zhong He ◽  
...  
Keyword(s):  
High Strength ◽  
Ferrite Matrix ◽  
Controlled Rolling ◽  
Dual Phase ◽  
Metastable Austenite ◽  
Transformation Zone ◽  
Transformation Rules ◽  
Rolling Experiment ◽  
Hot Rolled ◽  
Soft Ferrite

In according with the transformation rules of C-Si-Mn-Cr and C-Si-Mn-Cr-Mo tested steels, rolling experiment was carried out in lab. to analyze the effect of Mo on transformation, microstructure and property of high strength hot rolled dual phase steels. The results showed that the addition of element Mo decreased start temperature of ferrite transformation and restrains pearlite transformation. There was a metastable austenite zone between ferrite and bainite transformation zone of No.2 steel with 0.35% of Mo. After controlled rolling and step cooling process, dual phase microstructures in which fine martensite islands dispersed in soft ferrite matrix were obtained by two kinds of tested steel. With the addition of Mo, yield strength and tensile strength increased by 80MPa and 60MPa respectively, meanwhile, elongation increased slightly.

On the Practice of the Microstructure Adjustment to Improve the Strength-Plastic Comprehensive Performance of a C-Si-Mn Alloyed High-Strength Steel

2013 ◽  
Vol 631-632 ◽  
pp. 467-471
Author(s):  
Shuang Kuang ◽  
Guo Sen Zhu ◽  
Ying Hua Jiang
Keyword(s):  
Tensile Strength ◽  
Trip Steel ◽  
Dual Phase Steel ◽  
High Strength ◽  
Residual Austenite ◽  
Ferrite Matrix ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Metastable Austenite ◽  
Multi Phase

Four continuous annealing cycles were adopted to get four kinds of multi-phase steels using 0.2C-1.5Si-1.8Mn [wt%] alloyed raw steel and the microstructures and mechanical properties were investigated. The results show that traditional ferrite-martensite dual phase steel has a tensile strength of more than 1000MPa, but has the lowest strength-plastic product of only 18GPa%. The traditional ferrite, bainite and residual austenite TRIP steel has the highest elongation of 31% and hardening exponent of 0.24, but its tensile strength is just over 800MPa. Introducing hard matrix such as acicular bainitc ferrite or martensite to replace the polygonal ferrite matrix, meanwhile introducing metastable austenite, is conducive to obtain high strength and good ductility. Those kinds of modified TRIP steel with hard matrix can reach above 20GPa% of the strength-plastic product on the 1000MPa grade.

Effect of Nb on Transformation and Property of C-Si-Mn-Cr-Mo High Strength Hot-Rolled DP Steel

2014 ◽  
Vol 510 ◽  
pp. 110-113
Author(s):  
Le Yu Zhou ◽  
Bo Jiang ◽  
Dan Zhang ◽  
Chao Lei Zhang ◽  
Ya Zheng Liu
Keyword(s):  
Volume Fraction ◽  
High Strength ◽  
Strength Increase ◽  
Medium Temperature ◽  
Dp Steel ◽  
Transformation Rules ◽  
Rolling Experiment ◽  
Coiling Process ◽  
Tensile Strength Increase ◽  
Hot Rolled

Two kinds of C-Si-Mn-Cr-Mo tested steels were used to study the transformation rules and microstructure evolution during thermal mechanical experiment and rolling experiment. Effects of micro alloying element Nb on transformation and propertied were discussed. The result shows that Nb retards ferrite transformation, reduces ferrite volume fraction and refines the ferrite grain size and martensite colony size. After micro-alloying of 0.047wt%Nb, yield strength and tensile strength increase by 145MPa and 135MPa respectively under medium temperature coiling process. YS/TS ratio increases from 0.51 to 0.62, meanwhile, the decrease of elongation is not obvious. The grain refining strengthening and precipitation strengthening of Nb micro-alloying is effective to enhance the strength grade of hot rolled DP steel coiled at medium temperature.

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.

MITTAL DI-FORM T590, T600

Alloy Digest ◽  
2007 ◽  
Vol 56 (1) ◽  
Keyword(s):  
Tensile Strength ◽  
Automotive Industry ◽  
High Strength ◽  
Martensite Phase ◽  
Ferrite Phase ◽  
Dual Phase ◽  
Bend Strength ◽  
Low Carbon ◽  
Advanced High Strength Steel ◽  
Soft Ferrite

Abstract MITTAL DI-FORM T590 and T600 are low-carbon dual-phase steels containing manganese and silicon. Dual-phase (DP) steels are 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 strength ratios. The numeric designation in the grade name corresponds to the tensile strength in MPa. This datasheet provides information on microstructure, tensile properties, and bend strength as well as fatigue. It also includes information on forming. Filing Code: SA-558. Producer or source: Mittal Steel USA Flat Products.

scholarly journals Enhancing the Mechanical Properties of a Hot Rolled High-Strength Steel Produced by Ultra-Fast Cooling and Q&P Process

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 958 ◽  
Author(s):  
Teng Wu ◽  
Run Wu ◽  
Bin Liu ◽  
Wen Liang ◽  
Deqing Ke
Keyword(s):  
Retained Austenite ◽  
High Strength Steels ◽  
High Strength ◽  
Controlled Rolling ◽  
Grain Structure ◽  
Ultra Fast Cooling ◽  
Advanced High Strength Steels ◽  
Fast Cooling ◽  
Austenite Grains ◽  
Hot Rolled

The quenching and partitioning (Q&P) process of advanced high strength steels results in a significant enhancement in their strength and ductility. The development of controlled rolling and cooling technology provides an efficient tool for microstructural design in steels. This approach allows to control phase transformations in order to generate the desired microstructure in steel and, thus, to achieve the required properties. To refine grain structure in a Fe-Si-Mn-Nb steel and to generate the microstructure consisting of martensitic matrix with embedded retained austenite grains, hot rolling and pressing combined with ultrafast cooling and Q&P process is employed. The slender martensite in hot rolled Q&P steel improves the strength of test steel and the flake retained austenite improves the plasticity and work hardening ability through the Transformation Induced Plasticity (TRIP) effect.

MITTAL DI-FORM T500

Alloy Digest ◽  
2006 ◽  
Vol 55 (9) ◽  
Keyword(s):  
Tensile Strength ◽  
Automotive Industry ◽  
Dual Phase Steel ◽  
High Strength ◽  
Martensite Phase ◽  
Ferrite Phase ◽  
Dual Phase ◽  
Advanced High Strength Steel ◽  
Automotive Body ◽  
Soft Ferrite

Abstract Mittal Di-Form T500 is a dual-phase steel intended primarily for exposed outer automotive body panels (door, hoods, and fenders). Dual-phase steels are one of the important advanced high-strength steel 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 strength ratios and the name corresponds to the tensile strength. This datasheet provides information on tensile properties as well as deformation and fatigue. It also includes information on forming and joining. Filing Code: SA-556. Producer or source: Mittal Steel USA Flat Products.

Coarsening Behavior of Nanometer-Sized Carbides in Hot-Rolled High Strength Sheet Steel

2007 ◽  
Vol 539-543 ◽  
pp. 4813-4818 ◽  
Author(s):  
Yoshimasa Funakawa ◽  
Kazuhiro Seto
Keyword(s):  
Ostwald Ripening ◽  
Sheet Steel ◽  
High Strength ◽  
Large Change ◽  
Ferrite Matrix ◽  
Bearing Steel ◽  
Rolled Sheet ◽  
Coiling Temperature ◽  
The Stability ◽  
Hot Rolled

This study deals with a relationship between strength and coiling temperature of high strength hot-rolled sheet steels consisting of ferrite and nanometer-sized carbides in order to evaluate the stability of the strength against the variation of the coiling temperature. Ti-Mo-bearing and Ti-bearing steels were prepared to form (Ti,Mo)C and TiC in ferrite matrix, respectively. Ti-Mo-bearing steel exhibited the high strength even under the high temperature coiling while the strength of Ti-bearing steel decreased significantly. Ti-bearing steel just after transforming at 923K had the same hardness as that at 898K. In addition, hardness of Ti-bearing steel coiled at 898K decreased significantly by holding at 923K for 8.64ks while Ti-Mo-bearing steel did not represent a large change in hardness. These results confirm that (Ti,Mo)C is not coarsened easily by Ostwald ripening at the high coiling temperature unlike TiC. Consequently the retardation of Ostwald ripening of (Ti,Mo)C is attributed to the small amount of titanium in solution in Ti-Mo-bearing steel.

Microstructure and Property Control of Hot Rolled DP600 Steel

2011 ◽  
Vol 415-417 ◽  
pp. 938-942
Author(s):  
Le Yu Zhou ◽  
Ya Zheng Liu ◽  
Lian Hong Yang ◽  
Dan Zhang
Keyword(s):  
Dual Phase Steel ◽  
Volume Fraction ◽  
Ferrite Matrix ◽  
Accelerated Cooling ◽  
Dual Phase ◽  
Dp Steel ◽  
Fine Grain ◽  
Mechanical Experiment ◽  
Property Control ◽  
Hot Rolled

Thermal mechanical experiment of step-cooling of 600MPa hot-rolled DP steel after compressed was carried out on Gleeble-1500 thermal mechanical simulator, using design of butterfly-shaped sample. Microstructure evolution during step-cooling and its effect on mechanical property of tested steel were analyzed. It is shown that, dual phase microstructure which martensite islands disperses in fine grain ferrite matrix is obtained by holding for 8~10s at 670°C followed accelerated cooling to 200°C. With increasing of holding time, grain size of ferrite coarsens, and volume fraction of ferrite has few changes. Meanwhile, tensile strengths of tested steel are all near 600MPa. That is to say, ferrite transformation is adequate during holding for 8~10s at 670°C and tensile strength of dual phase steel is stable accordingly.

scholarly journals Effect of Carbon Content on V-bending in High-Strength TRIP-aided Dual-Phase Steel Sheets with Polygonal Ferrite Matrix

2020 ◽  
Vol 106 (12) ◽  
pp. 934-943
Author(s):  
Akihiko Nagasaka ◽  
Tomohiko Hojo ◽  
Masaya Fujita ◽  
Takumi Ohashi ◽  
Mako Miyasaka ◽  
...  
Keyword(s):  
Carbon Content ◽  
Dual Phase Steel ◽  
High Strength ◽  
Ferrite Matrix ◽  
Polygonal Ferrite ◽  
Dual Phase ◽  
Steel Sheets

scholarly journals Low-Carbon Ti-Mo Microalloyed Hot Rolled Steels: Special Features of the Formation of the Structural State and Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1584
Author(s):  
Alexander Zaitsev ◽  
Nataliya Arutyunyan
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Ferrite Matrix ◽  
Microalloyed Steels ◽  
Low Carbon ◽  
Bulk System ◽  
Hot Rolled ◽  
New Generation ◽  
Technological Strength

Low-carbon Ti-Mo microalloyed steels represent a new generation of high strength steels for automobile sheet. Excellent indicators of difficult-to-combine technological, strength, and other service properties are achieved due to the superposition of a dispersed ferrite matrix and a bulk system of nanoscale carbide precipitates. Recently, developments are underway to optimize thermo-deformation processing for the most efficient use of phase precipitates. The review summarizes and analyzes the results of studies of mechanical properties depending on the chemical composition and parameters of hot deformation of low-carbon Ti-Mo microalloyed steels. Particular attention is paid to the features of the formation and the influence of various types of phase precipitates and the dispersion of the microstructure on mechanical properties. The advantages of Ti-Mo microalloying system and the tasks requiring further solution are shown.

Sign in / Sign up

Export Citation Format

Share Document