Microstructure, Properties and Work Hardening Behavior of High Strength Cold Rolled Dual-Phase Steel

2011 ◽  
Vol 399-401 ◽  
pp. 1682-1686 ◽  
Author(s):  
Zheng Zhi Zhao ◽  
Zhi Gang Wang ◽  
Ai Min Zhao ◽  
Jie Yun Ye
Keyword(s):  
Work Hardening ◽  
Dual Phase Steel ◽  
High Strength ◽  
Distribution Patterns ◽  
Phase Region ◽  
Dual Phase ◽  
Two Phase ◽  
Soft Phase ◽  
Cold Rolled ◽  
Si Content

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.

scholarly journals Microstructure and Mechanical Properties of Dual-Phase Steel/ Mikrostruktura I Własności Mechaniczne Stali Dwufazowej

2014 ◽  
Vol 59 (4) ◽  
pp. 1257-1261
Author(s):  
K. Miernik ◽  
S. Pytel
Keyword(s):  
Mechanical Properties ◽  
Dual Phase Steel ◽  
High Strength ◽  
Phase Region ◽  
Dual Phase ◽  
Two Phase ◽  
Dp Steel ◽  
Direct Quenching ◽  
Microstructure And Mechanical Properties ◽  
Tempering Treatment

Abstract The paper presents results of microstructure and mechanical properties of the dual phase (DP) steel plate with 12 mm thickness produced by intercritical annealing at a two-phase region of ferrite and austenite (α + γ) and direct quenching in water. In addition the tempering treatment at temperature of 650°C was applied to investigate effect of martensite softening on mechanical properties of the tested steel. The parameters of heat treatment were designed to achieve the high strength while retaining optimum impact strength of the DP steel.

scholarly journals Assessment of the Hardening Behavior and Tensile Properties of a Cold-Rolled Bainitic–Ferritic Steel

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6662
Author(s):  
Emilio Bassini ◽  
Antonio Sivo ◽  
Daniele Ugues
Keyword(s):  
Strain Hardening ◽  
High Strength ◽  
Dual Phase ◽  
Low Carbon ◽  
Soft Phase ◽  
Bending Tests ◽  
Ductile Materials ◽  
Hardening Behavior ◽  
Material State ◽  
Cold Rolled

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.

Work-Hardening Behavior of Cold Rolled Interstitial-Free Steel Sheet and Dual Phase High Strength Steel Sheets Subjected to Two-Stage, Coaxial and Non-Coaxial Tension/Compression

2015 ◽  
Vol 651-653 ◽  
pp. 83-88 ◽  
Author(s):  
Satoshi Shirakami ◽  
Shigeru Yonemura ◽  
Tohru Yoshida ◽  
Noriyuki Suzuki ◽  
Toshihiko Kuwabara
Keyword(s):  
Work Hardening ◽  
Steel Sheet ◽  
High Strength ◽  
Dual Phase ◽  
Interstitial Free ◽  
If Steel ◽  
Two Stage ◽  
Work Hardening Behavior ◽  
Hardening Behavior ◽  
Cold Rolled

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.

USS DUAL PHASE 80

Alloy Digest ◽  
1978 ◽  
Vol 27 (12) ◽  
Keyword(s):  
United States ◽  
Corrosion Resistance ◽  
Yield Strength ◽  
Work Hardening ◽  
Steel Sheet ◽  
High Strength ◽  
Heat Treating ◽  
Dual Phase ◽  
United States Steel Corporation ◽  
Heavy Construction

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.

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

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.

scholarly journals A high-strength heterogeneous structural dual-phase steel

2019 ◽  
Vol 54 (19) ◽  
pp. 12898-12910 ◽  
Author(s):  
Bo Gao ◽  
Xuefei Chen ◽  
Zhiyi Pan ◽  
Jiansheng Li ◽  
Yan Ma ◽  
...  
Keyword(s):  
Dual Phase Steel ◽  
High Strength ◽  
Dual Phase
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