scholarly journals The nature of the change of the surface temperature of the workpiece during hot rolling of pipe steel

2018 ◽  
Vol 224 ◽  
pp. 01104 ◽  
Author(s):  
Vladimir Nekit ◽  
Sergey Platov ◽  
Maksim Krasnov
Keyword(s):  
Surface Temperature ◽  
Hot Rolling ◽  
Pipe Steel ◽  
Practical Importance ◽  
Experimental Studies ◽  
Phase Region ◽  
Work Piece ◽  
Two Phase ◽  
Deformation Processes ◽  
Two Stages

The article is devoted the experimental studies of deformation and temperature parameters of rolling the pipe steel on the rolling mill 5000 PJSC “MMK”. Knowledge of the regularities of the change in the surface temperature of work piece during hot rolling under the conditions of thermo mechanical deformation processes is of great theoretical and practical importance. The temperature conditions determine the energy and force parameters of rolling, as well as the mechanical properties and microstructure of the finished products. The experimental rolling was carried out in two stages: roughing at 6 passes at a temperature of 1050-900 ° C and finishing at 18-20 passes at a temperature below the start of the phase transformation of 900 ° C. The finishing rolling has been carried out in a two-phase region at the stage of polymorphic transformation in the steel. Significant differences in the nature of temperature changes at different stages of rolling are revealed.

Hot Rolling of FeSi Steels – Effects by Hot Rolling in the Two Phase Region

2011 ◽  
Vol 704-705 ◽  
pp. 1161-1166 ◽  
Author(s):  
J. Schneider ◽  
W. Jungnickel ◽  
W. Müller ◽  
Harti Hermann ◽  
R. Kawalla
Keyword(s):  
Phase Transformation ◽  
Hot Rolling ◽  
Experimental Studies ◽  
Phase Region ◽  
Process Conditions ◽  
Stress Strain ◽  
Two Phase ◽  
Strain Behaviour ◽  
Finish Rolling ◽  
Effect Of Hot Rolling

Finish rolling in the two-phase region may offer new possibilities for improving the properties of the FeSi steels with phase transformation. Therefore a deeper understanding of the effects by hot rolling in the two phase region or mixed rolling: multistep hot rolling in the two phase region and in the ferrite region on the evolution of the microstructure is desirable. In this paper we will present the results of our experimental studies on the effect of hot rolling in the intercritical state on the hardening and softening in the ferrite state. It will be demonstrated that depending on the process conditions at hot rolling the austenite ferrite transformation affects the stress strain behaviour in the ferrite state at multistep hot rolling remarkable.

Mechanisms of Layer Structure Formation in Peritectic Alloys

1997 ◽  
Vol 481 ◽  
Author(s):  
P. Mazumder ◽  
R. Trivedi ◽  
A. Karma
Keyword(s):  
Structure Formation ◽  
Layer Structure ◽  
Experimental Studies ◽  
Growth Conditions ◽  
Phase Region ◽  
Primary Phase ◽  
Two Phase ◽  
Novel Structure ◽  
Basic Ideas ◽  
Narrow Composition Range

ABSTRACTThe mechanisms of layer structure formation in the two phase region of peritectic systems are discussed. Under diffusive growth conditions, a banded structure is predicted within a narrow composition range in the hypoperitectic composition. Experimental studies show the formation of an oscillatory structure in the hyperperitectic region. It is shown that this structure is induced by convection in the melt, and it is a novel structure in which a large single tree-like structure of primary phase is surrounded by the peritectic phase. Basic ideas of convection that lead to this tree-like morphology are described.

A statistical theory of liquid crystalline mixtures: phase separation

1976 ◽  
Vol 352 (1668) ◽  
pp. 41-56 ◽  
Keyword(s):  
Liquid Crystal ◽  
Phase Separation ◽  
Liquid Crystalline ◽  
Experimental Studies ◽  
Phase Region ◽  
Crystal Formation ◽  
Two Phase ◽  
First Order ◽  
Repulsive Forces

The molecular field theory of multicomponent liquid crystalline mixtures, developed by Humphries, James & Luckhurst, has been extended to investigate the possibility of phase separation in binary mixtures of rods and spheres. This extension indicates that the addition of a spherical solute to a liquid crystal depresses the transition from the isotropic to the nematic phase. The solute induced phase transition is first order, although the nematic and isotropic phases are found to be separated by a two-phase region consisting of both nematic and isotropic phases. These qualitative conclusions of the theory are in complete accord with experiment and there is also reasonable agreement with certain quantitative predictions. The same problem has been tackled using a lattice model with purely repulsive anisotropic interactions; this theory would appear to be marginally less successful than our own which is based on a weaker anisotropic potential. Consequently it is not possible to use experimental studies of phase separation in binary liquid crystal mixtures to demonstrate the rôle of repulsive forces in liquid crystal formation.

A Study of the Effect of Extrusion Parameters on the Properties of Extruded Zr-2.5Nb Pressure Tubes

2012 ◽  
Vol 585 ◽  
pp. 371-375
Author(s):  
Nachiket Keskar ◽  
Vikrant Raizada ◽  
Vaibhaw Kumar ◽  
Sanjay Kumar Jha ◽  
Dinesh Srivastava ◽  
...  
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Extrusion Process ◽  
Phase Region ◽  
Work Piece ◽  
Two Phase ◽  
Strain And Strain Rate ◽  
Transus Temperature ◽  
Flow Stress Data ◽  
Temperature Strain

The hot extrusion of Zr-2.5Nb alloy has been simulated using an FEM based software and validated by the experimental measurements during real extrusion process. The flow stress data for Zr-2.5Nb alloy at different temperatures, strain and strain rates were generated by hot compression testing on Gleeble Machine. The flow stress data, obtained both below β transus temperature in two phase α+β region as well as above β transus temperature in β phase region, were directly used in the FEM simulation of extrusion process, eliminating the need for any assumptions regarding material plastic flow law. Two important extrusion parameters, viz. included die angle and reduction ratio, were varied and for each set of conditions, temperature, strain and strain rate at different nodal points of the tube at different stages of extrusion were calculated. The extrusion parameters were optimized to obtain minimum variation in the force, temperature, strain and strain rate in the extruded product. A fair agreement has been found between the measured values of the applied ram force and the temperature profile at the die landing area in a 3780 ton horizontal extrusion press and those obtained through simulations. The effect of the friction and heat transfer coefficient between the die chamber and work piece was also investigated in this study.

scholarly journals Deformation and Phase Transformation of Disordered α Phase in the (α + γ) Two-Phase Region of a High-Nb TiAl Alloy

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4817
Author(s):  
Haitao Zhou ◽  
Fantao Kong ◽  
Yanbo Wang ◽  
Xiangwu Hou ◽  
Ning Cui ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Dynamic Recrystallization ◽  
Hot Rolling ◽  
Tial Alloy ◽  
Phase Region ◽  
Two Phase ◽  
Continuous Dynamic Recrystallization ◽  
Α Phase ◽  
Continuous Dynamic ◽  
Lower Temperature

In this paper, the deformation and phase transformation of disordered α phase in the (α + γ) two-phase region in as-forged Ti-44Al-8Nb-(W, B, Y) alloy were investigated by hot-compression and hot-packed rolling. The detailed microstructural evolution demonstrated that the deformed microstructure was significantly affected by the deformation conditions, and the microstructure differences were mainly due to the use of a lower temperature and strain rate. Finer α grains were formed by the continuous dynamic recrystallization of α lamellae and α grains distributed around lamellar colonies. Moreover, the grooved γ grains formed by the phase transformation from α lamellae during hot rolling cooperated with and decomposed α lamellae. A microstructure evolution model was built for the TiAl alloy at 1250 °C during hot rolling.

On the Plastic Flow Behavior of Ti-6Al-4V Alloy during Multi-Stand Tandem Hot Rolling

2010 ◽  
Vol 638-642 ◽  
pp. 407-412
Author(s):  
Li Qing Chen ◽  
Shuang Liang ◽  
Xiang Hua Liu
Keyword(s):  
Plastic Flow ◽  
Hot Rolling ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Rolling Process ◽  
Processing Parameters ◽  
Phase Region ◽  
Two Phase ◽  
Heat Treated ◽  
Structural Parts

Titanium alloys are usually used as structural parts in forged and subsequent heat treated state. Up to now, there have been rare researches appeared on their shaping or forming by multi-stand tandem hot rolling. In this article, we choose Ti-6Al-4V as experimental material and a simulated research has been carried out in a thermo-mechanical simulator MMS-300 to model its hot-rolling process. The plastic flow behavior for Ti-6Al-4V alloy during hot-working has been determined at various deformation temperatures and deformation rates by considering its hot-rolling in single or two phase region. The deformation mechanisms at elevated temperatures are also analyzed in correlation with its deformation activation energy. This research can provide guidance in designing processing parameters for hot-rolling of Ti-6Al-4V alloy.

Solution Properties and Phase Behavior of Ammonium Hexylene Octyl Succinate in Water and Water-Oil System

1970 ◽  
Vol 3 (1) ◽  
Author(s):  
Md. Hamidul Kabir ◽  
Ravshan Makhkamov ◽  
Shaila Kabir
Keyword(s):  
Critical Micelle Concentration ◽  
Phase Behavior ◽  
Liquid Crystalline ◽  
Carbon Number ◽  
Phase Region ◽  
Solution Properties ◽  
Middle Phase ◽  
Two Phase ◽  
Lamellar Liquid Crystal ◽  
Drug Ingredient

The solution properties and phase behavior of ammonium hexylene octyl succinate (HOS) was investigated in water and water-oil system. The critical micelle concentration (CMC) of HOS is lower than that of anionic surfactants having same carbon number in the lipophilic part. The phase diagrams of a water/ HOS system and water/ HOS/ C10EO8/ dodecane system were also constructed. Above critical micelle concentration, the surfactant forms a normal micellar solution (Wm) at a low surfactant concentration whereas a lamellar liquid crystalline phase (La) dominates over a wide region through the formation of a two-phase region (La+W) in the binary system. The lamellar phase is arranged in the form of a biocompatible vesicle which is very significant for the drug delivery system. The surfactant tends to be hydrophilic when it is mixed with C10EO8 and a middle-phase microemulsion (D) is appeared in the water-surfactant-dodecane system where both the water and oil soluble drug ingredient can be incorporated in the form of a dispersion. Hence, mixing can tune the hydrophile-lipophile properties of the surfactant. Key words: Ammonium hexylene octyl succinate, mixed surfactant, lamellar liquid crystal, middle-phase microemulsion. Dhaka Univ. J. Pharm. Sci. Vol.3(1-2) 2004 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

scholarly journals Revisiting the Bøggild Intergrowth in Iridescent Labradorite Feldspars: Ordering, Kinetics, and Phase Equilibria

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 727
Author(s):  
Shiyun Jin ◽  
Huifang Xu ◽  
Seungyeol Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atom Probe ◽  
Phase Region ◽  
Two Phase ◽  
Subsolidus Phase ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission

The enigmatic Bøggild intergrowth in iridescent labradorite crystals was revisited in light of recent work on the incommensurately modulated structures in the intermediated plagioclase. Five igneous samples and one metamorphic labradorite sample with various compositions and lamellar thicknesses were studied in this paper. The lamellar textures were characterized with conventional transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The compositions of individual lamellae were analyzed with high-resolution energy-dispersive X-ray spectroscopy (EDS) mapping and atom probe tomography (APT). The average structure states of the studied samples were also compared with single-crystal X-ray diffraction data (SC-XRD). The Na-rich lamellae have a composition of An44–48, and the Ca-rich lamellae range from An56 to An63. Significant differences between the lamellar compositions of different samples were observed. The compositions of the Bøggild intergrowth do not only depend on the bulk compositions, but also on the thermal history of the host rock. The implications on the subsolidus phase relationships of the plagioclase feldspar solid solution are discussed. The results cannot be explained by a regular symmetrical solvus such as the Bøggild gap, but they support an inclined two-phase region that closes at low temperature.

scholarly journals Thermodynamics and Machine Learning Based Approaches for Vapor–Liquid–Liquid Phase Equilibria in n-Octane/Water, as a Naphtha–Water Surrogate in Water Blends

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 413
Author(s):  
Sandra Lopez-Zamora ◽  
Jeonghoon Kong ◽  
Salvador Escobedo ◽  
Hugo de Lasa
Keyword(s):  
Machine Learning ◽  
Liquid Phase ◽  
Phase Equilibria ◽  
Aspen Plus ◽  
Phase Region ◽  
Two Phase ◽  
Technical Literature ◽  
Phase Liquid ◽  
Liquid Vapor ◽  
Vapor Liquid

The prediction of phase equilibria for hydrocarbon/water blends in separators, is a subject of considerable importance for chemical processes. Despite its relevance, there are still pending questions. Among them, is the prediction of the correct number of phases. While a stability analysis using the Gibbs Free Energy of mixing and the NRTL model, provide a good understanding with calculation issues, when using HYSYS V9 and Aspen Plus V9 software, this shows that significant phase equilibrium uncertainties still exist. To clarify these matters, n-octane and water blends, are good surrogates of naphtha/water mixtures. Runs were developed in a CREC vapor–liquid (VL_ Cell operated with octane–water mixtures under dynamic conditions and used to establish the two-phase (liquid–vapor) and three phase (liquid–liquid–vapor) domains. Results obtained demonstrate that the two phase region (full solubility in the liquid phase) of n-octane in water at 100 °C is in the 10-4 mol fraction range, and it is larger than the 10-5 mol fraction predicted by Aspen Plus and the 10-7 mol fraction reported in the technical literature. Furthermore, and to provide an effective and accurate method for predicting the number of phases, a machine learning (ML) technique was implemented and successfully demonstrated, in the present study.

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