scholarly journals Study on microstructure and texture of high-strength plastic cold-rolled dual-phase DP980 steel

Author(s):  
W W Wang ◽  
L Liu ◽  
G Y Li
Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6662
Author(s):  
Emilio Bassini ◽  
Antonio Sivo ◽  
Daniele Ugues

The automotive field is continuously researching safer, high-strength, ductile materials. Nowadays, dual-phase (DP) steels are gaining importance, since they meet all these requirements. Dual-phase steel made of ferrite and bainite is the object of a complete microstructural and mechanical characterization, which includes tensile and bending tests. This specific steel contains ferrite and bainite in equal parts; ferrite is the soft phase while bainite acts as a dispersed reinforcing system. This peculiar microstructure, together with fine dispersed carbides, an extremely low carbon content (0.09 wt %), and a minimal degree of strain hardening (less than 10%) allow this steel to compete with traditional medium-carbon single-phase steels. In this work, a full pearlitic C67 steel containing 0.67% carbon was used as a benchmark to build a comparative study between the DP and SP steels. Moreover, the Crussard–Jaoul (C-J) and Voce analysis were adopted to describe the hardening behavior of the two materials. Using the C-J analysis, it is possible to separately analyze the ferrite and bainite strain hardening and understand which alterations occur to DP steel after being cold rolled. On the other hand, the Voce equation was used to evaluate the dislocation density evolution as a function of the material state.


2015 ◽  
Vol 651-653 ◽  
pp. 83-88 ◽  
Author(s):  
Satoshi Shirakami ◽  
Shigeru Yonemura ◽  
Tohru Yoshida ◽  
Noriyuki Suzuki ◽  
Toshihiko Kuwabara

In-plane tension/compression tests of a cold rolled interstitial-free (IF) steel and sheet a 980MPa dual phase high strength steel sheet (980DP) were carried out to investigate the work-hardening behavior under two-stage loading paths. The two-stage loading paths consist of the uniaxial tension/compression for the rolling direction (RD) followed by unloading and subsequent uniaxial tension/compression in the 0°, 45° and 90° directions from the first loading direction (0°-, 45°- and 90°-loading). The work hardening behavior in the second loading was different between the 980DP and the IF steel. It was found that the work hardening behaviors were significantly affected by the inner product of the strain rate mode tensors for the first and second loading and that the effect of the deformation mode (tension/compression) was small.


2016 ◽  
Vol 879 ◽  
pp. 217-223 ◽  
Author(s):  
Marion Bellavoine ◽  
Myriam Dumont ◽  
Josée Drillet ◽  
Philippe Maugis ◽  
Véronique Hebert

Microalloying elements Ti and Nb are commonly added to high-strength Dual Phase steels as they can provide efficient means for additional strengthening due to grain refinement and precipitation strengthening mechanisms. In the form of solute elements or as fine carbonitride precipitates, Ti and Nb are also expected to have a significant effect on the microstructural changes during annealing and especially on recrystallization kinetics. The present work investigates the influence of microalloying elements Ti and Nb on recrystallization in various cold-rolled Dual Phase steel grades with the same initial microstructure but different microalloying contents. Using complementary experimental and modeling approaches makes it possible to give some clarifications regarding both the nature of this effect and the comparative efficiency of Ti and Nb on delaying recrystallization. It is shown that niobium is the most efficient micro-alloying element to impede recrystallization and that the predominant effect is solute drag.


2011 ◽  
Vol 399-401 ◽  
pp. 1682-1686 ◽  
Author(s):  
Zheng Zhi Zhao ◽  
Zhi Gang Wang ◽  
Ai Min Zhao ◽  
Jie Yun Ye

Two kinds of high strength cold rolled dual-phase steel with different Si content were trial-produced in the laboratory. Tensile strength and elongation of the two steels exceed 1000MPa and 15%, respectively. The phase transformation behaviors of both steels were compared and investigated in continuous cooling process by thermal dilatometer. The effects of Si on the mechanical properties and microstructures of dual-phase steel were studied by tensile testing, OM and SEM observation. The results show that the two phase region (α+γ) is enlarged, the precipitation and growth of pro-eutectoid ferrite is promoted, and the morphology and distribution patterns of martensite are improved for high Si steel. Both steels show two-stage strain hardening characteristics. StageⅠ (ε<0.05), the solution of Si hinder the movement of dislocations, make the work hardening exponent of high Si steel is higher than that low Si steel. At stage Ⅱ (ε>0.05), the compatibility and delivery between hard phase and soft phase eliminate the differences between the two steels.


2013 ◽  
Vol 20 (12) ◽  
pp. 61-68 ◽  
Author(s):  
Zhi-gang Wang ◽  
Ai-min Zhao ◽  
Zheng-zhi Zhao ◽  
Jie-yun Ye ◽  
Jing-jing Chen ◽  
...  

1981 ◽  
Vol 67 (2) ◽  
pp. 343-352
Author(s):  
Kiwami KURIHARA ◽  
Kenji ARAKI ◽  
Kazuhide NAKAOKA

Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).


Alloy Digest ◽  
1977 ◽  
Vol 26 (4) ◽  

Abstract YS-T 50 to YS-T 140 Steels comprise a series of high-strength, cold-rolled steels designed to meet performance and weight-saving objectives. They are an extension of Youngstown's series of hot-rolled high-strength steels (see Youngstown YS-T Steel, Alloy Digest SA-261, March 1971). The YS-T 50 to YS-T 140 steels have minimum yield strengths ranging from 50,000 psi to 140,000 psi. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on heat treating, machining, and joining. Filing Code: SA-331. Producer or source: Youngstown Sheet and Tube Company.


Alloy Digest ◽  
1978 ◽  
Vol 27 (12) ◽  

Abstract USS Dual Phase 80 is a high-strength steel sheet which has a dual phase structure of martensite and ferrite. It provides all the benefits of higher strength with little sacrifice in ductility, formability or weldability. Dual Phase 80 gains strength as it is formed through rapid work hardening of its unique microstructure; in fact, it increases from its delivered yield strength of 50,000 psi up to 80,000 psi (or more) in forming. Its final strength depends on the amount of forming. Its many applications include automotive vehicles, farm equipment and heavy construction equipment. This datasheet provides information on composition, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-352. Producer or source: United States Steel Corporation.


Alloy Digest ◽  
2007 ◽  
Vol 56 (2) ◽  

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.


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