Effect of Hot-Band Annealing on the Microstructure of Non-Oriented Electrical Steel Containing Copper

2012 ◽  
Vol 502 ◽  
pp. 238-242
Author(s):  
Di Nan ◽  
Yan Ping Zeng ◽  
Hui Jie Cui ◽  
Zi Yu Zhou
Keyword(s):  
Electrical Steel ◽  
Volume Fraction ◽  
Volume Fractions ◽  
Grain Sizes ◽  
Different Temperatures ◽  
Hot Band ◽  
Hot Rolled

The grain sizes and precipitates in hot-rolled bands of the non-oriented electrical steel containing Cu were quantitatively studied while the effect of hot-band annealing on microstructure was evaluated by hot-band annealing at different temperatures. The average sizes of recrystallized grains after coiling at 650°C are in the range of 24~29μm. After hot-band annealing at 850°C for 1h, grains coarsened dramatically. The volume fractions of precipitates in hot-rolled bands after coiling at 650°C for different time are 15~18%. After hot-band annealing, precipitates coarsened and distributed sparsely, and the volume fraction of them decreased to less than 10%.

Effect of Coiling and Normalizing Annealing on the Microstructure of a Newly Developed Cold-Rolled Non-Oriented Electrical Steel

2013 ◽  
Vol 302 ◽  
pp. 298-303
Author(s):  
Yan Ping Zeng ◽  
Hui Jie Cui
Keyword(s):  
Grain Boundary ◽  
Electrical Steel ◽  
Volume Fraction ◽  
Low Carbon ◽  
Coiling Temperature ◽  
Pinning Effect ◽  
Cold Rolled ◽  
Average Size ◽  
Hot Rolled ◽  
Normalizing Annealing

In order to improve the magnetic properties, copper was added to cold-rolled non-oriented electrical steel with low carbon and low silicon. The grain sizes and precipitates in hot-rolled bands of the investigated steel were quantitatively studied. The results show that the recrystallization of deformed grains has been completed in the coiled bands and the recrystallized grains are fine due to low coiling temperature and pinning effect of precipitates. But grains grew up obviously after normalizing annealing at 850°C for 1h because the mobility of grain boundary is so good at elevated temperature that pinning effect of precipitates can’t prevent the migration of grain boundary. Thus, normalizing annealing is necessary to obtain large grains in hot-rolled band. In addition, the typical morphologies of precipitates in hot-rolled bands are square, rectangular, hexagonal and triangular and they are identified as AlN phase based on EDS and SEAD analysis, which can form by epitaxial growth mode. For the hot-rolled bands coiled at 550°C, the increase of average size and volume fraction of AlN particles with coiling time is mainly related to the growth of AlN particles, whereas for the hot-rolled bands coiled at 650°C, the decrease of average size and the increase of volume fraction of AlN particles with coiling time are chiefly attributed to the precipitation of many small AlN particles. The volume fraction of AlN particles increases with coiling temperature because they precipitate more quickly at 650°C than at 550°C.

The Effect of Hot-Rolled Coiling Time on the Texture of a New Cold-Rolled Non-Oriented Electric Steel

2011 ◽  
Vol 194-196 ◽  
pp. 375-378
Author(s):  
Guan Qiao Hu ◽  
Yan Ping Zeng ◽  
Hai Lin Chen
Keyword(s):  
Hot Rolling ◽  
Electrical Steel ◽  
Volume Fraction ◽  
Test Results ◽  
Electric Steel ◽  
Coiling Temperature ◽  
Goss Texture ◽  
Cold Rolled ◽  
Hot Rolled

The effects of hot-rolling coiling time on texture of a new cold-rolled non-oriented electrical steel containing copper were investigated. The test results showed that the final product texture consists of γ-fibr textures, α-fibre textures and Goss. With adding coiling time ,the density of {111}<110> and {112}<110> decreased,the inverse Goss texture {001}<110> increased. The volume fraction of {100} raised with coiling time. As a certain coiling temperature, it can improve the intensity of textures {100},{110}at proper coiling time.

Difference of Microstructure and Fatigue Properties between Forged and Rolled Ti-6Al-4V

2012 ◽  
Vol 508 ◽  
pp. 161-165 ◽  
Author(s):  
Yoon Seok Lee ◽  
Mitsuo Niinomi ◽  
Masaaki Nakai ◽  
Junko Hieda ◽  
Takashi Maeda ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Volume Fraction ◽  
Fatigue Behavior ◽  
Longitudinal Section ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Mechanical Processing ◽  
Grain Sizes ◽  
Α Phase ◽  
Hot Rolled

In the Present Study, the Effects of the Microstructural Morphologies of a Ti-6Al-4V (Ti-64) Alloy on its Fatigue Behavior Were Investigated. Ti-64 Bars Were Subjected to Two Different Thermo-Mechanical Processing Methods. The First Sample, Referred to as Material-A, Had a Forged Microstructure with the Average Primary α Volume Fraction of 44%. The Second One, Referred to as Material-B, Had a Hot-Rolled Microstructure with the Average Primary α Volume Fraction of 43%. Fatigue Tests Were Performed on each Sample to Obtain S-N Curves. The Microstructure of each Sample Was Observed Using an Optical Microscopy in Order to Measure the Grain Sizes of the Primary α and Secondary α Phases. The Results of the Fatigue Tests Indicated that Material-B Demonstrates Better Fatigue Strength than Material-A. The Microstructure of the Longitudinal Section of each Material Was Also Observed to Analyze the Results of the Fatigue Tests. The Measured Diameters and Volume Fractions of the Primary α Phases of the Two Types of Materials Are Similar. On the other Hand, the Secondary α Width of each Material Is Different. It Is Found that Fatigue Strength Is Related to the Width of the Secondary α Phase.

Simulation of the Mechanical Behaviour of Metal Matrix Composites

2011 ◽  
Vol 678 ◽  
pp. 49-60 ◽  
Author(s):  
Siegfried Schmauder ◽  
Ulrich Weber ◽  
Andreas Reuschel ◽  
Markus Willert
Keyword(s):  
Fracture Criterion ◽  
Volume Fraction ◽  
Cell Model ◽  
Matrix Composites ◽  
Normal Stresses ◽  
Unit Cell Model ◽  
Plastic Properties ◽  
Volume Fractions ◽  
Wide Range ◽  
Different Temperatures

A model based on the geometry of the phases is introduced in order to investigate the mechanical properties of interpenetrating microstructures. In order to characterize the elastic and elastic-plastic properties of the composite a self consistent unit cell model is applied on a wide range of volume fractions for an Al/TiO2 composite. Besides the volume fraction a microstructural based parameter is used, the matricity, to describe the mutual circumvention of both phases. Computations are carried out for different temperatures and void volume fractions. In addition a conservative fracture criterion based on critical normal stresses is applied to derive realistic stress strain curves.

scholarly journals Low-carbon cast microalloyed steel intercritically heat-treated at different temperatures: microstructure and mechanical properties

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Hadi Torkamani ◽  
Shahram Raygan ◽  
Carlos Garcia Mateo ◽  
Yahya Palizdar ◽  
Jafar Rassizadehghani ◽  
...  
Keyword(s):  
Carbon Content ◽  
Volume Fraction ◽  
Block Size ◽  
Tensile Tests ◽  
Total Elongation ◽  
Martensite Phase ◽  
Low Carbon ◽  
Steel Increase ◽  
Different Temperatures ◽  
The Impact

AbstractIn this study, dual-phase (DP, ferrite + martensite) microstructures were obtained by performing intercritical heat treatments (IHT) at 750 and 800 °C followed by quenching. Decreasing the IHT temperature from 800 to 750 °C leads to: (i) a decrease in the volume fraction of austenite (martensite after quenching) from 0.68 to 0.36; (ii) ~ 100 °C decrease in martensite start temperature (Ms), mainly due to the higher carbon content of austenite and its smaller grains at 750 °C; (iii) a reduction in the block size of martensite from 1.9 to 1.2 μm as measured by EBSD. Having a higher carbon content and a finer block size, the localized microhardness of martensite islands increases from 380 HV (800 °C) to 504 HV (750 °C). Moreover, despite the different volume fractions of martensite obtained in DP microstructures, the hardness of the steels remained unchanged by changing the IHT temperature (~ 234 to 238 HV). Applying lower IHT temperature (lower fraction of martensite), the impact energy even decreased from 12 to 9 J due to the brittleness of the martensite phase. The results of the tensile tests indicate that by increasing the IHT temperature, the yield and ultimate tensile strengths of the DP steel increase from 493 to 770 MPa, and from 908 to 1080 MPa, respectively, while the total elongation decreases from 9.8 to 4.5%. In contrast to the normalized sample, formation of martensite in the DP steels could eliminate the yield point phenomenon in the tensile curves, as it generates free dislocations in adjacent ferrite.

scholarly journals An Intrinsic Material Tailoring Approach for Functionally Graded Axisymmetric Hollow Bodies Under Plane Elasticity

2021 ◽  
Author(s):  
Hassan Mohamed Abdelalim Abdalla ◽  
Daniele Casagrande
Keyword(s):  
Optimization Problem ◽  
Volume Fraction ◽  
Minimum Principle ◽  
Equivalent Stress ◽  
Micromechanical Model ◽  
Plane Elasticity ◽  
Functionally Graded ◽  
Pontryagin Minimum Principle ◽  
Volume Fractions ◽  
Material Tailoring

AbstractOne of the main requirements in the design of structures made of functionally graded materials is their best response when used in an actual environment. This optimum behaviour may be achieved by searching for the optimal variation of the mechanical and physical properties along which the material compositionally grades. In the works available in the literature, the solution of such an optimization problem usually is obtained by searching for the values of the so called heterogeneity factors (characterizing the expression of the property variations) such that an objective function is minimized. Results, however, do not necessarily guarantee realistic structures and may give rise to unfeasible volume fractions if mapped into a micromechanical model. This paper is motivated by the confidence that a more intrinsic optimization problem should a priori consist in the search for the constituents’ volume fractions rather than tuning parameters for prefixed classes of property variations. Obtaining a solution for such a class of problem requires tools borrowed from dynamic optimization theory. More precisely, herein the so-called Pontryagin Minimum Principle is used, which leads to unexpected results in terms of the derivative of constituents’ volume fractions, regardless of the involved micromechanical model. In particular, along this line of investigation, the optimization problem for axisymmetric bodies subject to internal pressure and for which plane elasticity holds is formulated and analytically solved. The material is assumed to be functionally graded in the radial direction and the goal is to find the gradation that minimizes the maximum equivalent stress. A numerical example on internally pressurized functionally graded cylinders is also performed. The corresponding solution is found to perform better than volume fraction profiles commonly employed in the literature.

scholarly journals A Micro-mechanical Investigation of Empirical Models for the Effective Properties of Aligned Short-Fibre Composites

1995 ◽  
Vol 4 (1) ◽  
pp. 096369359500400
Author(s):  
T.D. Papathanasiou
Keyword(s):  
Aspect Ratio ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Fibre Volume ◽  
Short Fibre ◽  
Computational Results ◽  
Volume Fractions ◽  
Fibre Composites ◽  
Effective Tensile Modulus ◽  
Fibre Aspect Ratio

The predictions of the Halpin equation concerning the effect of fibre volume fraction and fibre aspect ratio on the effective tensile modulus of uniaxially aligned short-fibre composites are compared with computational experiments on three-dimensional, multiparticle composite samples. The method of boundary elements is used to model the mechanical behaviour of composite specimens consisting of up to 40 discrete aligned fibres randomly dispersed in an elastic matrix. Statistical averages of computational results relating the effective tensile modulus to the aspect ratio and volume fraction of the fibres are found to agree very well with the predictions of the Halpin equation for fibre aspect ratio up to 10 and fibre volume fractions up to 20%. Computational results seem to indicate that the predictions of the Halpin equation fall bellow those of micro-mechanical models at higher volume fractions.

Variant Selection in Zr Alloys: How Many Variants Generated from one Beta Grain?

2005 ◽  
Vol 105 ◽  
pp. 133-138 ◽  
Author(s):  
Pierre Barbéris ◽  
Frank Montheillet ◽  
Cédric Chauvy
Keyword(s):  
Elastic Energy ◽  
Volume Fraction ◽  
Variant Selection ◽  
Energy Minimum ◽  
Maximum Volume ◽  
Volume Fractions ◽  
Minimum Number ◽  
Simplifying Assumptions ◽  
Maximum Volume Fraction ◽  
Zr Alloys

The elastic energy of a set of the twelve variants generated during the b ® a transformation of zirconium, with volume fractions fi, i=1..12, is derived with simplifying assumptions and the conditions on the fi to reach the energy minimum are established analytically. The minimum number of variants needed to reach this minimum is shown to be 6, and in this case, the variants have very specific volume fractions. Another result is that the maximum volume fraction of any variant is 1/3.

scholarly journals The Investigation of Effects of Temperature and Nanoparticles Volume Fraction on the Viscosity of Copper Oxide-ethylene Glycol Nanofluids

2017 ◽  
Author(s):  
Mohammad Hemmat Esfe
Keyword(s):  
Ethylene Glycol ◽  
Copper Oxide ◽  
Volume Fraction ◽  
Relative Viscosity ◽  
Experimental Results ◽  
Different Temperatures ◽  
Nanoparticles Volume Fraction ◽  
Effects Of Temperature ◽  
Nanofluid Viscosity ◽  
Experimental Values

In the present article, the effects of temperature and nanoparticles volume fraction on the viscosity of copper oxide-ethylene glycol nanofluid have been investigated experimentally. The experiments have been conducted in volume fractions of 0 to 1.5 % and temperatures from 27.5 to 50 °C. The shear stress computed by experimental values of viscosity and shear rate for volume fraction of 1% and in different temperatures show that this nanofluid has Newtonian behaviour. The experimental results reveal that in a given volume fraction when temperature increases, viscosity decreases, but relative viscosity varies. Also, in a specific temperature, nanofluid viscosity and relative viscosity increase when volume fraction increases. The maximum amount of increase in relative viscosity is 82.46% that occurs in volume fraction of 1.5% and temperature of 50 °C. Some models of computing nanofluid viscosity have been suggested. The greatest difference between the results obtained from these models and experimental results was down of 4 percent that shows that there is a very good agreement between experimental results and the results obtained from these models.

The Influence of Multiple Inclusions on the Cauchy Stress of a Spherical Particle-Reinforced Composite Under Uniaxial Loading

2014 ◽  
Author(s):  
Ke Niu ◽  
Armin Abedini ◽  
Zengtao Chen
Keyword(s):  
Spherical Particle ◽  
Single Particle ◽  
Volume Fraction ◽  
Unit Cell ◽  
Spherical Particles ◽  
Uniaxial Tensile ◽  
Cauchy Stress ◽  
Particle Volume ◽  
Volume Fractions ◽  
Unit Cells

This paper investigates the influence of multiple inclusions on the Cauchy stress of a spherical particle-reinforced metal matrix composite (MMC) under uniaxial tensile loading condition. The approach of three-dimensional cubic multi-particle unit cell is used to investigate the 15 non-overlapping identical spherical particles which are randomly distributed in the unit cell. The coordinates of the center of each particle are calculated by using the Random Sequential Adsorption algorithm (RSA) to ensure its periodicity. The models with reinforcement volume fractions of 10%, 15%, 20% and 25% are evaluated by using the finite element method. The behaviour of Cauchy stress for each model is analyzed at a far-field strain of 5%. For each reinforcement volume fraction, four models with different particle spatial distributions are evaluated and averaged to achieve a more accurate result. At the same time, single-particle unit cell and analytical model were developed. The stress-strain curves of multi-particle unit cells are compared with single-particle unit cells and the tangent homogenization model coupled with the Mori-Tanaka method. Only little scatters were found between unit cells with the same particle volume fractions. Multi-particle unit cells predict higher response than single particle unit cells. As the volume fraction of reinforcements increases, the Cauchy stress of MMCs increases.

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