scholarly journals Effect of Martensitic Transformation and Grain Size on the Surface Roughening Behavior in SUS 304 and SUS 316 Thin Metal Foils

Eng ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 167-182
Author(s):  
Abdul Aziz ◽  
Ming Yang
Keyword(s):  
Volume Fraction ◽  
Stress Test ◽  
Strain Level ◽  
Coarse Grain ◽  
Uniaxial Tensile ◽  
Surface Roughening ◽  
Initial State ◽  
Austenitic Phase ◽  
Fine Grain ◽  
Grain Misorientation

The surface roughening and martensitic phase transformation (MPT) of SUS 304 and SUS 316 were studied through two experiments: a uniaxial tensile stress test, repeated for five cycles, and an Scanning Electron Microscope–Electron Backscaterr Diffraction (SEM-EBSD) investigation. The MPT and martensitic volume fraction (Mf) were evaluated following the tensile test. The correlation between MPT, Mf, and surface roughening behavior was investigated. The experiment showed that an increase in the strain level from 0.4% to 1% increased the MPT and Mf, which transformed from a metastable austenitic phase in SUS 304. The increased strain level increased the surface roughening for various grain sizes (Dg), from fine grain (Dg < 3 μm) to coarse grain (Dg ≥ 3 μm). SUS 304 and SUS 316 are used so that the surface roughening mechanism between SUS 304 and SUS 316, with different phase conditions and at a similar Dg, can be determined. The results showed that the surface roughening increased for both fine and coarse grain at strain levels of 0.4% and 1%; however, a larger increase of surface roughening was obtained for coarse grain. In coarse grain, surface roughening increased significantly not only with a low MPT, but also with a low grain deformation. In coarse grain, the surface roughening increased proportionally to the strain level (εp) because of the low MPT and weak grain. In fine grain, the surface roughening did not increase proportionally to the εp because of the high MPT, which increased the grain strength in SUS 304. In the fine grain of SUS 304, the increase of surface roughening was nearly the same both at strain levels of 0.4% and 1%, because the MPT and Mf were nearly the same. The surface roughening with the same εp and almost the same Dg in SUS 304 and SUS 316 fine grain was nearly the same, because the grain deformation almost produced the same relative inclination between neighboring grains in the initial state direction to the surface. The inter-grain movement changed the grain orientation. Based on kernel average misorientation (KAM) mapping, the local grain misorientation in SUS 304 was higher than that in SUS 316. This indicated that the fine-grain SUS 304 is harder than the fine-grain SUS 316. There is no MPT in SUS 316 because of the higher austenitic phase, which is affected by the austenitic former, such as Ni.

scholarly journals Effect of Martensitic Transformation and Grain Misorientation on Surface Roughening Behavior of Stainless Steel Thin Foils

Eng ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 372-385
Author(s):  
Abdul Aziz ◽  
Ming Yang ◽  
Tetsuhide Shimizu ◽  
Tsuyoshi Furushima
Keyword(s):  
Stainless Steel ◽  
Volume Fraction ◽  
Thin Foil ◽  
Total Strain ◽  
Coarse Grain ◽  
Uniaxial Tensile ◽  
Surface Roughening ◽  
Fine Grain ◽  
Thin Foils ◽  
Grain Misorientation

The surface roughening (Ra), martensitic phase transformation (MPT), and grain misorientation (GMO) behavior of stainless steel 304 and 316 in various grain sizes (Dg) were studied experimentally, including five cycles of sequential uniaxial tensile stress testing and Scanning Electron Microscope-Electron Back Scattered Diffraction (SEM-EBSD) investigation. The MPT and GMO characteristics were sequentially investigated using tensile testing and SEM-EBSD analysis. The correlation between MPT, GMO, martensitic volume fraction (Mf), and Ra behavior were investigated. The experimental results showed that increasing the total strain from 5.0% to 25.0% increased the MPT, GMO, and Mf, which were transformed from the metastable austenitic phase in stainless steel (SUS) 304. The increasing total strain increased Ra for all kinds of Dg. Furthermore, SUS 304 and SUS 316 were used to compare the roughening mechanism. The MPT was very high and spread uniformly in fine grain of SUS 304 thin foil, but the MPT was low and not uniform in coarse grain of SUS 304 thin foil. There was no MPT in SUS 316 thin foil, both in coarse and fine grain. The GMO in fine grains, both in SUS 304 and SUS 316 thin foils, spread uniformly. The GMO in coarse grains, both in SUS 304 and SUS 316 thin foils, did not spread uniformly. Surface roughness increased higher in coarse grain than fine grain for both of SUS 304 and SUS 316 thin foil. SUS 304 increased higher than SUS 316 thin foil. The effect of inhomogeneous deformation due to the MPT is a more important factor than GMO in coarse grain.

Effects of Deformation Mode on Resistivity Curve Used for Estimating Martensite Induced in Stainless Steel

2010 ◽  
Vol 638-642 ◽  
pp. 2992-2997 ◽  
Author(s):  
Hidefumi Date
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Linear Relation ◽  
Volume Fraction ◽  
Tensile Deformation ◽  
Deformation Mode ◽  
Transformation Process ◽  
Martensite Formation ◽  
Austenitic Phase ◽  
Ε Phase

The martensite induced in three types of austenitic stainless steel, which indicate the different stability of the austenitic phase (γ), were estimated by the resistivity measured during the tensile deformation or compressive deformation at the temperatures 77, 187 and 293 K. The resistivity curves were strongly dependent on the deformation mode. The volume fraction of the martensite (α’) was also affected by the deformation mode. The ε phase, which is the precursor of the martensite and is induced from the commencement of the deformation, decreased the resistivity. However, lots of defects generated by the deformation-induced martensite increased the resistivity. The experimental facts and the results shown by the modified parallelepiped model suggested a complicated transformation process depending on each deformation mode. The results shown by the model also suggested a linear relation between the resistivity and the martensite volume at the region of the martensite formation. The fact denoted that the resistivity is mostly not controlled by the austenite, ε phase and martensite, but by the defects induced due to the deformation-induced martensite.

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.

Analysis of Cracking Process in Conditions of High-Temperature Creep of Castings Form the Modified Superalloy IN-713C

2013 ◽  
Vol 212 ◽  
pp. 247-254
Author(s):  
Marek Cieśla ◽  
Franciszek Binczyk ◽  
Marcin Mańka
Keyword(s):  
High Temperature ◽  
Creep Resistance ◽  
Nickel Superalloy ◽  
Morphological Properties ◽  
Coarse Grain ◽  
High Temperature Creep ◽  
Temperature Creep ◽  
Fine Grain ◽  
Initiation And Propagation ◽  
Cracking Process

mpact of complex modification and filtration during pouring into moulds on durability has been evaluated in this study in conditions of high-temperature creep of castings made from nickel superalloy IN-713C post production rejects. The conditions of initiation and propagation of cracks in the specimens were analysed with consideration of morphological properties of material macro-, micro-and substructure. It has been demonstrated that in conditions of high-temperature creep at temperature 980°C with stress σ =150 MPa creep resistance of the IN-713C superalloy increases significantly with the increase of macrograin size. Creep resistance of specimens made of coarse grain material was significantly higher than the resistance of fine grain material.

scholarly journals Constraining the Age of Floodplain Levels Along the Lower Section of River Tisza, Hungary

2016 ◽  
Vol 9 (1-2) ◽  
pp. 39-44 ◽  
Author(s):  
György Sipos ◽  
Tímea Kiss ◽  
Orsolya Tóth
Keyword(s):  
Flood Plain ◽  
Luminescence Dating ◽  
Coarse Grain ◽  
Lower Section ◽  
Vegetation Control ◽  
Fine Grain ◽  
Energy Environment ◽  
The Given ◽  
Luminescence Characteristics ◽  
Grain Size Fractions

Abstract During the Late Pelistocene-Holocene transition the fluvial landscape of the Great Hungarian Plain changed considerably as a consequence of tectonic, climatic and geomorphological factors. Geochronology, and especially luminescence dating, is a very important tool in reconstructing these changes. The present study focuses on the Lower-Tisza region and addresses the timing of the development of different floodplain levels. In the meantime the luminescence characteristics of the investigated alluvial sediments were also assessed, with a special emphasis on the comparison of silty fine grain and sandy coarse grain results, as in the given medium and low energy environment fine grain sediments are more abundant, however, based on the literature, coarse grain samples are more reliable in terms of luminescence dating. Measurements were performed on 12 samples originating from the point bars of two large palaeo-meanders, representing different floodplain levels along the river. Results indicate the applicability of both grain size fractions for dating purposes, though fine grain subsamples overestimate in average by 1.5 ka the ages yielded by coarse grain subsamples. Consequently, fine grain samples can be used for outlining only general trends, and results need to be controlled by coarse grain measurements where possible. Based on the ages received, the upper floodplain was actively formed until 13-15 ka, when incision and the development of an intermediate floodplain level started. The meander on the intermediate flood plain level developed then very actively until 9 ka. As indicated by the received age information the intensity of meander formation could be highly affected by climatic and especially vegetation control. However, reconstruction can be refined later by further sampling and the application of the results of the present paper.

The Effect of Grain Refiners for Aluminium Alloy Containing Mn-Ti-Sr Dispersoid

2006 ◽  
Vol 519-521 ◽  
pp. 449-454
Author(s):  
V.T. Vacariu ◽  
Aurelian Buzaianu ◽  
Eugeniu Vasile ◽  
R. Trusca ◽  
Petru Moldovan
Keyword(s):  
Volume Fraction ◽  
Lightweight Design ◽  
High Volume ◽  
Sr Modification ◽  
Fine Grain ◽  
Homogenization Time ◽  
Structural Applications ◽  
Complex Shapes ◽  
Metallic Compounds

The new structural applications of aluminum materials are determined by intelligent lightweight design: the demand of safety, ecology, recycling and by economics. Al-Si alloys allow complex shapes to be cast. Metallurgical a high volume fraction of fine dispersoid which are less about 0.1 microns in size are useful for retaining a fine grain. In the 6061 series of alloys, iron combines with aluminium and silicon to form two types of commune inter-metallic, (beta AlFeSi and alpha AlFeSi).The type of inter-metallic that is present these alloys will have an important bearing on the homogenization time, workability and quality of the surface finish. The microstructure of the as-cast samples was evaluated by electronic microscopy and the morphology of inter-metallic compounds related to the efficiently modification. Mn-Ti-Sr modification of Al-alloys is normally accompanied by an increase in porosity in the casting.

Cellulose Whiskers Micro-Fibers Effect in the Mechanical Proprieties of PP and PLA Composites Fibers Obtained by Spinning Process

2011 ◽  
Vol 146 ◽  
pp. 12-26 ◽  
Author(s):  
A. Gherissi ◽  
R.Ben Cheikh ◽  
E. Dévaux ◽  
Fethi Abbassi
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Tensile Tests ◽  
Advanced Materials ◽  
Uniaxial Tensile ◽  
Failure Resistance ◽  
Cellulose Whiskers ◽  
Limit Strength

In this study, we present the manufacturing process of two new composites materials in the form of long fibers of polylactic-acid (PLA) or polypropylene (PP), reinforced by cellulose whiskers micro-fibers loads. In order to evaluate the mechanical properties of these advanced materials, a several uniaxial tensile tests were carried out. The PP and the PLA have initially been spinning without the addition of cellulose whiskers micro-fibers. In order to study the effects of cellulose whiskers micro-fibers reinforcements in the Mechanical behavior of the PLA and PP filaments, we determinate the proprieties of these advanced material from the tensile results. For the PP composite filaments material case, the whiskers reinforcement increases Young's modulus and failure resistance, but it reduces the limit strength failure. For the PLA composites the addition of 1% wt of cellulose whiskers from the total volume fraction of the material, increase the Young’s modulus more than 50% and a decrease of the failure resistance and the limit strength of composite. The obtained composites fibers are very rigid and brittle. What follows, that the addition of cellulose whiskers micro fibers in PP matrix, provides mechanical properties more convenient compared to the PLA matrix.

scholarly journals The Effect of Nonequilibrium Structure State on the Creep and Superplastic Behaviour of Materials

2008 ◽  
Vol 575-578 ◽  
pp. 1031-1037
Author(s):  
M.M. Myshlyaev
Keyword(s):  
Mechanical Behaviour ◽  
Coarse Grain ◽  
Zinc Alloy ◽  
Cobalt Alloy ◽  
Superplastic Behaviour ◽  
Fine Grain ◽  
Grain Zinc ◽  
Nonequilibrium Structure ◽  
Structure State ◽  
Kinetic Principle

Mechanical behaviour at creep and superplasticity of coarse grain and monocrystalline aluminum under torsion, of coarse grain molybdenum, of fine grain zinc alloy and amorphous cobalt alloy under tension are discussed from unified positions. It is shown that realization of their superplasticity requires fulfillment of structure-kinetic principle.

scholarly journals Nanoparticle amount, and not size, determines chain alignment and nonlinear hardening in polymer nanocomposites

2017 ◽  
Vol 114 (16) ◽  
pp. E3170-E3177 ◽  
Author(s):  
H. Samet Varol ◽  
Fanlong Meng ◽  
Babak Hosseinkhani ◽  
Christian Malm ◽  
Daniel Bonn ◽  
...  
Keyword(s):  
Strain Hardening ◽  
Polymer Nanocomposites ◽  
Nonlinear Elasticity ◽  
Volume Fraction ◽  
Uniaxial Tensile ◽  
Large Strains ◽  
Chain Alignment ◽  
Strain Hardening Behavior ◽  
Polymer Chain Alignment ◽  
Nonlinear Hardening

Polymer nanocomposites—materials in which a polymer matrix is blended with nanoparticles (or fillers)—strengthen under sufficiently large strains. Such strain hardening is critical to their function, especially for materials that bear large cyclic loads such as car tires or bearing sealants. Although the reinforcement (i.e., the increase in the linear elasticity) by the addition of filler particles is phenomenologically understood, considerably less is known about strain hardening (the nonlinear elasticity). Here, we elucidate the molecular origin of strain hardening using uniaxial tensile loading, microspectroscopy of polymer chain alignment, and theory. The strain-hardening behavior and chain alignment are found to depend on the volume fraction, but not on the size of nanofillers. This contrasts with reinforcement, which depends on both volume fraction and size of nanofillers, potentially allowing linear and nonlinear elasticity of nanocomposites to be tuned independently.

scholarly journals Effect of Reverse-phase Transformation Annealing Process on Microstructure and Mechanical Properties of Medium Manganese Steel

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1633 ◽  
Author(s):  
Yan Zhao ◽  
Lifeng Fan ◽  
Bin Lu
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Volume Fraction ◽  
Lath Martensite ◽  
Phase Region ◽  
Manganese Steel ◽  
Reverse Phase ◽  
Two Phase ◽  
Fine Grain ◽  
Martensite Microstructure

In order to develop a third-generation automobile steel with powerful strength and elongation, we propose a method through high temperature quenching and two-phase region reverse-phase transformation annealing to develop such steel with 0.13% C and 5.4% Mn. To investigate the microstructure evolution and mechanical properties of manganese steel, SEM, XRD and TEM are employed in our experiments. Experimental results indicate that the microstructure after quenching is mainly lath martensite microstructure with average of lath width at 0.5 μm. The components of the steel after along with reverse-phase transformation annealing are ultra-fine grain ferrite, lath martensite and different forms of austenite microstructure. When the temperature at 625 °C, the components of the steel mainly includes lath martensite microstructure and ultra-fine grain ferrite and the fraction of austenite volume is only 5.09%. When the annealing temperature of reverse-phase transformation increase into 650 °C and 675 °C, the austenite appears in the boundary of the ferritic grain boundary and the boundary of lath martensite as the forms of bulk and lath. The phenomenon appears in the bulk of austenite, and the size of is 0.22 μm, 0.3 μm. The fraction of austenite volume is 22.34% at 675 °C and decreases into 9.32% at 700 °C. The components of austenite mainly includes ultra-fine grained ferrite and lath martensite. Furthermore, the density of decreases significantly, and the width of martensite increases into 0.32 μm. In such experimental settings, quenching at 930 °C with 20 min and at 675 °C with 30 min reverse-phase transformation annealing, the austenite volume fraction raises up to 22.34%.

Sign in / Sign up

Export Citation Format

Share Document