Influence of Deformation on Phase Transformation and Precipitation of Steels for Oil Country Tubular Goods

Timoshenkov, Alexander; Warczok, Piotr; Albu, Mihaela; Klarner, Jürgen; Kozeschnik, Ernst; Gruber, Gerald; Sommitsch, Christof

doi:10.1002/srin.201300198

Cited by 12 publications

(12 citation statements)

References 34 publications

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“…In addition, this type of diagram can be modified to a deformation continuously cooling transformation (DCCT) type, which also includes the effect of previous deformation. Such diagrams then find their practical application in the case of the controlling of steel forming processes (rolling, forging), and their findings often lead to an improvement in the economics of the production process [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Effect of Strain on Transformation Diagrams of 100Cr6 Steel

et al. 2020

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Based on dilatometric tests, the effect of various values of previous deformation on the kinetics of austenite transformations during the cooling of 100Cr6 steel has been studied. Dilatometric tests have been performed with the use of the optical dilatometric module of the plastometer Gleeble 3800. The obtained results were compared to metallographic analyses and hardness measurements HV30. Uniaxial compression deformations were chosen as follows: 0, 0.35, and 1; note that these are true (logarithmic) deformations. The highly important finding was the absence of bainite. In addition, it has been verified that with the increasing amount of deformation, there is a further shift in the pearlitic region to higher cooling rates. The previous deformation also affected the temperature martensite start, which decreased due to deformation. The deformation value of 1 also shifted the critical cooling rate required for martensite formation from the 12 °C/s to 25 °C/s.

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Section: Introductionmentioning

confidence: 99%

Effect of Strain on Transformation Diagrams of 100Cr6 Steel

et al. 2020

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“…A C1 and A C3 were obtained by a DIL 805 thermal dilatometer, and phase transformation temperatures during heating (A C1 and A C3 ) should be close to the equilibrium temperatures as a result of the relatively slow heating rate (0.05 C s À1 ). [16,17] The dynamic CCT curves were obtained by a Gleeble 3500 thermomechanical machine. As shown in Figure 1, the specimens were heated to 1200 C at a rate of 10 C s À1 and soaked at 1200 C for 300 s to dissolve alloy carbides.…”

Section: Methodsmentioning

confidence: 99%

Phase Transformation and Precipitation Mechanism of Nb Microalloyed Bainite–Martensite Offshore Platform Steel at Different Cooling Rates

Xiong

Song

et al. 2019

steel research int.

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The phase transformation and precipitation mechanism of Nb microalloyed offshore platform steel during continuous cooling are studied by the thermal expansion method and transmission electron microscopy. The results show that a large amount of NbC is precipitated in the investigated steel during phase transformation and is classified into three types according to its size: Type I (>100 nm) is randomly generated in the austenitization stage; type II (20–100 nm) is precipitated by stress induction during thermal deformation; and type III (≈10 nm) is formed by the combination of segregated C and Nb during the cooling process after the formation of bainitic ferrite matrix. In addition, herein, a model of phase transition and precipitation behavior at different cooling rates is designed. At a low cooling rate (0.5 °C s−1), the microstructure consists of a granular structure formed by diffusion and granular bainite formed by shearing, which is a diffusion phase transformation. At a medium cooling rate (3 °C s−1), the orientation relationship of ferrite and austenite is [001]α//[011]γ and (110)α//(−1−11)γ, which is semidiffusion and a half‐shear mechanism. At a high cooling rate (15 °C s−1), there are a large number of intertwined dislocations in martensite, which is a shear mechanism.

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“…Согласно [8] доля материала, претерпевшего рекристаллизацию, как функция скорости миграции границ зерен v b и скорости образования зародышей рекристаллизации N  , может быть представлена в виде 4Чтобы учесть влияние выделений вторых фаз при описании скорости миграции границы зерна, рассматривается суперпозиция сил, действующих на границу зерна аустенита. В этом случае скорость миграции границы описывается выражением [8]: где γ -удельная энергия границы зерна, равная 0,5 Дж/м 2 [8], а τ = Gb 2 /2 -энергия дислокации, приходящаяся на единицу ее длины.…”

Section: модельunclassified

Predicting the Size of Carbonitride Particles of Complex Composition in Hot Deformation of Low-Alloyed Steel

Popov¹,

Горбачев²,

Pasynkov³

2018

ФИ (FR)

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Предложена модель для описания эволюции нескольких ансамблей карбонитридных частиц сложного состава в низколегированной стали при горячей деформации в температурном диапазоне стабильного аустенита. В модели учитывается взаимное влияние изменения при деформации таких структурных параметров, как плотность дислокаций, средний размер зерна аустенита (с учетом релаксационных процессов рекристаллизации и возврата, а также процессов выделения вторых фаз), и эволюции карбонитридных фаз. Модель также учитывает полидисперсность ансамблей выделений. В основе метода лежит совместное использование деформационной модели на основе так называемого метода «внутренней переменной» и разработанной нами ранее кинетической модели для описания эволюции вторых фаз в многофазных многокомпонентных системах. Основными особенностями кинетической модели является возможность моделирования поведения выделений комплексного состава, а также совместной эволюции ансамблей выделений нескольких составов (с учетом образования новых зародышевых центров). На основе модели создана программа, с помощью которой выполнены расчеты для стали, низколегированной ниобием и титаном, для двух термомеханических обработок. Полученные результаты сопоставлялись с экспериментальными данными, где было показано их удовлетворительное согласие. Ключевые слова: компьютерное моделирование, эволюция выделений, многокомпонентные системы, аустенитизация, горячая деформация predicTinG The SiZe of carboniTride parTicleS of coMplex coMpoSiTion in hoT deforMaTion of loW-alloyed STeel 1,2 popov V.V., 1,2 Gorbachev i.i., 1 pasynkov a.yu.

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Influence of Deformation on Phase Transformation and Precipitation of Steels for Oil Country Tubular Goods

Cited by 12 publications

References 34 publications

Effect of Strain on Transformation Diagrams of 100Cr6 Steel

Effect of Strain on Transformation Diagrams of 100Cr6 Steel

Phase Transformation and Precipitation Mechanism of Nb Microalloyed Bainite–Martensite Offshore Platform Steel at Different Cooling Rates

Predicting the Size of Carbonitride Particles of Complex Composition in Hot Deformation of Low-Alloyed Steel

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