bluuebunny/crossref_metadata_2025 huggingface dataset:
Three-Stage Character of Strain Hardening of α-Ti in Tension Conditions
Authors: Roth A. , Amouzou K.E.K. , Lebyodkin M.A. , Richeton T. , Lebedkina T.A. , Lecomte J.S.
Published: May 2014

The plasticity of hexagonal materials is strongly anisotropic and involves different microscopic mechanisms such as mechanical twinning and dislocation glide. Twins are often considered to be responsible for a particular three-stage shape of compression curves, unusual for polycrystals with cubic structure. However, the role of twins remains a matter of debate and it is not clear if the same features appear in other testing conditions. We performed tensile tests on commercially-pure Ti samples cut along the rolling and the transverse direction, which yielded several unexpected results. In particular, the work hardening rate was found to be lower in the latter case, although the EBSD measurements revealed for them a larger volume fraction of twins. Also, the two kinds of specimens showed an opposite sign for the strain-rate effect on the proneness to the three-stage shape of the deformation curves. As a first approach, these observations are compared to the results derived from a simple Kocks-Mecking model. The possible role of twinning and dislocation glide on the anisotropy of mechanical behavior of titanium is then discussed.
Fatigue and Fracture Behavior of Porous TiNi Alloys
Authors: Nakaş G. Ipek , Aşık Emin Erkan , Tunca Bensu , Bor Şakir
Published: May 2014

While the wide range of applications of TiNi alloys make them highly appealing due to their shape memory and superelasticity properties, production of TiNi in the porous form further enlarges their application fields. Porous TiNi alloys have been studied extensively for biomedical applications due to their elastic modulus similar to that of bone. Accordingly, TiNi foams have been widely characterized in terms of their various mechanical properties; however, their fatigue properties have not been well studied, even though, it has a vital importance in structural applications such as medical implants. In the scope of this study, fatigue behavior of TiNi foams, which were produced from prealloyed powders by Mg space holder technique, was examined via load controlled cyclic compression-compression tests. The endurance limit of the tested foams was taken as the stress level at which the specimens sustain their integrity without showing any sign of failure beyond 106 cycles. TiNi foams with porosity contents in the range of 39-64 vol%, which is suitable for bone ingrowth, were determined to have an endurance limit ranging in between 26-89 MPa. On the other hand, fractography studies on the failed foams after fatigue testing revealed that the failure occurs by the coalescence of micro-cracks initiated from pore walls leading to macro-crack formation aligned at 45o with respect to the loading axis.
Mechanical Properties of Ti-Mn-Al-Fe Alloys after Solution Heat Treatment
Authors: Sumi Yoshinori , Ueta Shigeki , Ueda Masato , Ikeda Masahiko
Published: May 2014

To develop a low-cost β Ti alloy, the influence of Mn in Ti-Al-Fe alloys on solution treatment behavior and mechanical properties was investigated. Although it has been known that Mn is a β stabilizing element in Ti alloys, Mn has not often been used for Ti alloys in spite of its low cost and sustainability so far, since Mn easily evaporates under low-pressure atmosphere, which is a common condition when melting Ti alloys. Therefore, general β Ti alloys include a high amount of expensive elements such as V, Mo and Nb to stabilize the β matrix phase. In this paper, Ti-8 to 10Mn-1Fe-3Al alloys (mass%) were produced by cold crucible levitation melting under atmospheric pressure to inhibit Mn loss by vaporization. As results, it was found that the β transus was lowered with increasing Mn amount, but the full β phase was obtained in solution-treated alloys over 1113 K, even in the 8%Mn alloy. Through tensile and Charpy impact tests of the full beta-phase samples, the ductility and toughness increase monotonically with increasing Mn amount from 8 to 10% in spite of the tensile strength having almost constant value. Ti-10Mn-1Fe-3Al alloy has the best mechanical properties among the alloys used in this study.
Tensile Strength and Impact Toughness of Gallium-Bearing Near-α Titanium Alloys
Authors: Kitashima Tomonori , Suresh K.S. , Yamabe-Mitarai Y. , Iwasaki S.
Published: May 2014

The present study aims to quantify the properties of Ga-bearing near-titanium alloys in order to aid the future design of new compositions with Ga addition. The effect of different amounts of Sn and Ga, with an almost constant value in the Al equivalent without the formation of 2 phase, on microstructure, tensile strength and Charpy impact toughness was investigated at room temperature and 650°C. The microstructures after forging, hot rolling and heat treatment showed a bimodal structure. Increasing Ga decreased the 0.2% proof stress at 650°C. However, these alloys showed similar impact value at room temperature which was about 40 J/cm2. Increasing the amount of Ga increased the volume fraction of the equiaxed phase. The amount of Ga had only a minor effect on grain size, misorientation angles and grain aspect ratios of the alloy. However, Ga addition had a strong influence on the evolution of texture. Formation of <10-10> and <10-11> || normal direction (ND) fibers were observed in the Ga added samples, in addition to <0001> || ND fiber with a weak <10-11> || ND fiber. The Ga-free sample contained a strong <0001> || ND fiber. Other fibers were not observed.
Development of Fracture Assessment Standards in Japan with Weibull Stress
Authors: Minami Fumiyoshi
Published: May 2014

This paper describes the fracture assessment standards developed in Japan, where the Weibull stress is implemented to correct the CTOD toughness for constraint loss in structural components. ISO 27306 and WES 2808 (Japan Welding Engineering Society Standard) are presented. Discussion is given on the effects of strength mismatch and residual stress in welds.
18CrNiMo7-6 with TRIP-Effect for Increasing the Damage Tolerance of Gear Components — Part II: Microstructure and Mechanical Properties
Authors: Bambach Margarita D. , Stieben Andreas , Bleck Wolfgang
Published: May 2014

High performance components such as gear wheels shall be resistant to rolling-contact fatigue. This type of failure is usually caused by effects occurring on a microscopic scale, such as crack initiation at non-metallic inclusions. Much effort has been invested so far in improving the steel cleanliness. However, these high performance components often do not reach the desired service life. Preliminary failure within the guarantee terms still occurs which leads to high warranty costs. Alternative to improving steel cleanliness, the damage tolerance of high performance components could be increased by inducing the TRIP-effect around the crack tip. Due to high local strain hardening, martensite transformation occurs. The high compressive stresses related to it could delay or stop crack propagation by reducing stress concentrations via plastic deformation. In part II of this study, the microstructures and mechanical properties of the steels modified via Al-alloying and heat treated in process routes according to part I are compared to conventional 18CrNiMo7-6. Special interest is paid to the stability of the residual austenite as well as to the change in strain hardening rate under tension.
Finite Element Implementation of a Bonding Model and Application to Roll Bonding of Aluminum Sheets of Largely Different Yield Strength
Authors: Bambach Markus , Pietryga Michael P. , Mikloweit A. , Hirt Gerhard , Karhausen Kai F.
Published: May 2014

Roll bonding is a joining-by-forming operation, in which two or more metallic strips or plates are bonded permanently through the pressure and plastic deformation in the roll gap. Although roll bonding has been successfully used in industrial production over many years, difficulties occur especially when materials of largely different yield strength are roll-bonded, e.g. when hard aluminum alloys are clad with soft commercially pure aluminum. Examples are AA2024 sheets used in wing and fuselage structures of aircrafts, which are clad with AA1050 to improve the corrosion resistance. Likewise, aluminum sheets for heat exchangers consist of a hard base material that is clad with a soft solderable aluminum alloy. In these cases, the strength difference may influence the bonding behavior since the softer face sheet has to transmit the deformation to the harder core material. To analyze and optimize such cases, a bonding model integrated into a numerical framework for the simulation of the roll bonding process is required. In this paper, a finite element model is presented, in which the development of bond strength is simulated using a cohesive contact formulation. The model is used to study the bonding behavior of laboratory-scale roll bonding trials of two aluminum alloys with a large difference in yield strength. It is found that shear stresses are generated towards the end of the roll gap that may exceed the shear bond strength created earlier in the roll gap such that no firm bond is obtained. The conditions under which bonding is successful are analyzed using a finite element simulation study with varying yield stress differences and pass reductions and summarized in a map.
Development of Ultra-Fine Grained Dual-Phase Steels: Mechanism of Grain Refinement during Inter-Critical Deformation
Authors: Karmakar Anish , Misra R.D.K. , Neogy Suman , Chakrabarti Debalay
Published: May 2014

Heavy deformation of metastable austenite (below Ae3) or both austenite and ferrite in the two-phase region (between Ar3 and Ar1) has been found to develop ultra-fine ferrite grain structures with average grain sizes less than 3 μm. The sequence of different dynamic softening mechanisms involved in the grain refinement during heavy intercritical deformation, such as, dynamic recovery, dynamic recrystallization, and dynamic strain induced austenite→ferrite transformation, has been analyzed by considering strain partitioning between austenite and ferrite. Grain refinement is expected to be dictated by dynamic strain induced transformation (DSIT) at higher deformation temperatures (>1100°C) and pronounced dynamic recovery of ferrite at lower deformation temperatures (<1100°C). Evolution of crystallographic texture was dependent on the grain refinement mechanism and gamma fiber components (ND//<111>) and alpha fiber components (RD//<110>) dominated the texture at higher and lower deformation temperatures, respectively.
Microstructure Evolution of Martensitic Ti-6Al-4V Alloy during Warm Deformation
Authors: Chao Qi , Hodgson Peter , Beladi Hossein
Published: May 2014

The microstructure evolution of martensitic Ti-6Al-4V alloy was investigated through uniaxial hot compression at 700°C and a strain rate of 10-3 s-1. A combination of scanning electron microscopy observation in conjunction with high resolution electron back scattered diffraction (EBSD) was used to characterize the microstructure in detail. The development of the microstructure displayed continuous fragmentation of martensitic laths with increasing strain (i.e. continuous dynamic recrystallization), concurrently with decomposition of supersaturated martensite resulting in the formation of equiaxed grains. At a strain of 0.8, an ultrafine equiaxed grained structure with mostly high angle grain boundaries was successfully obtained. The current work proposes a novel approach to produce equiaxed ultrafine grains in a Ti-6Al-4V alloy through thermomechanical processing of a martensitic starting microstructure.
A Novel Concept of High Cu, Low Mn, Environmentally-Friendly Weathering Steels
Authors: Comineli Osvaldo
Published: May 2014

A novel concept of hot shortness control on copper containing weathering steels is proposed. The weathering effect of copper addition in steels and its improvement in the mechanical and impact properties by age hardening are well known. Again, it is also very well know the problem of cracks on hot processing of those steels, caused by liquid copper segregation, the “hot shortness”. Hot shortness is the main problem of commercial producing of copper containing steels because of the increase of cost production caused by cracks the Ni addition to prevent them. Recent research found that copper segregates surrounding MnS inclusions in the steel, worsening the copper segregation caused by the preferential oxidation of iron on the hot processing of copper containing steels, which is the traditional cause of the “hot shortness”. The same results also show that copper additionally precipitates as CuS in the bulk of the steel. This work points that the “hot shortness” can then be prevented by reducing the Mn in the steel, rather than by the expensive Ni addition. Reducing Mn means reduction of inclusions of MnS sites for copper segregation in the steel. Residual sulphur can therefore be trapped by the copper as finer CuS precipitates, so copper is then dissolved in the bulk of the steel rather than segregated. This paper introduces an alternative solution for the problem of the “hot shortness” by partially or fully replacing the Mn by Cu in those steels. It is then proposed a novel concept of low Mn, or Mn free, Cu containing weathering steels in which Cu replaces Mn in trapping the S. That new steel opens the possibility to a cheaper and easier controls of the “hot shortness” so the copper contamination from scraps become a technological benefit because of its age hardening and weathering effect on steels. The recycling of highly copper contaminated scraps is another important environmental advantage. The conclusion of this work is that the current results introduces a new technology of cheaper copper containing low Mn, or Mn free, high strength, environmentally-friendly weathering steels with high potential market for different welded on shore and offshore specifications.
Control of Oriented Extracellular Matrix Similar to Anisotropic Bone Microstructure
Authors: Nakano Takayoshi , Matsugaki Aira , Ishimoto Takuya , Todai Mitsuharu , Serizawa Ai , Suetoshi Ryoichi , Noyama Yoshihiro , Fujitani Wataru
Published: May 2014

Bone microstructure is dominantly composed of anisotropic extracellular matrix (ECM) in which collagen fibers and epitaxially-oriented biological apatite (BAp) crystals are preferentially aligned depending on the bone anatomical position, resulting in exerting appropriate mechanical function. The regenerative bone in bony defects is however produced without the preferential alignment of collagen fibers and the c-axis of BAp crystals, and subsequently reproduced to recover toward intact alignment. Thus, it is necessary to produce the anisotropic bone-mimetic tissue for the quick recovery of original bone tissue and the related mechanical ability in the early stage of bone regeneration.
Our group is focusing on the methodology for regulating the arrangement of bone cells, the following secretion of collagen and the self-assembled mineralization by oriented BAp crystallites. Cyclic stretching in vitro to bone cells, principal-stress loading in vivo on scaffolds, step formation by slip traces on Ti single crystal, surface modification by laser induced periodic surface structure (LIPSS), anisotropic collagen substrate with the different degree of orientation, etc. can dominate bone cell arrangement and lead to the construction of the oriented ECM similar to the bone tissue architecture. This suggests that stress/strain loading, surface topography and chemical anisotropy are useful to produce bone-like microstructure in order to promote the regeneration of anisotropic bone tissue and to understand the controlling parameters for anisotropic osteogenesis induction.
Microstructural Features Intervening in Hot Workability of Free Cutting Steels
Authors: Gonzalez N. , Revilla M.C. , López Beatriz , Rodriguez-Ibabe J.M.
Published: May 2014

Free cutting steels belong to a family associated with hot workability problems. This study has focused on the analysis of microstructural features located near the surface of the billet before and after reheating and how they can affect the nucleation/propagation of damage during initial hot working operations. The work has been done with free cutting steels containing sulfur contents ranging from 0.32 to 0.42%. The relevance of clustering of inclusions, their location at grain boundaries or triple points and the influence of softening mechanisms (as recrystallization) have been considered with the help of several parameters determined by image analysis techniques.
Biofunctional Surface Layer and its Bonding Strength in Low Modulus β-Type Titanium Alloy for Biomedical Applications
Authors: Niinomi Mitsuo , Nakai Masaaki , Hieda Junko , Cho Ken , Goto Takashi , Hanawa Takao
Published: May 2014

Recently, low-modulus β-type titanium alloys have been the focus of considerable attention because of their high biocompatibility and their low moduli that make them effective for inhibiting bone atrophy and for enhancing bone remodeling. However, the biofunctinalities of titanium alloys, such as bone conductivity, blood compatibility, and soft tissue compatibility, are poor. Therefore, surface modification techniques such as bioactive ceramic surface modification and blood-and soft-tissue-compatible polymer surface modification are applied to titanium alloys. Hydroxyapatite (HAp) surface modification via metal organic chemical vapor deposition (MOCVD) and segmented polyurethane (SPU) surface modification via silane coupling treatment are effective techniques to add biofunctionalites to titanium alloys. HAp surface modification via MOCVD and SPU surface modification using three kinds of silane coupling agents on a low modulus beta-type titanium alloy, namely, TNTZ, are discussed. Moreover, the bonding strengths of HAp and SPU on the surface of TNTZ, which are important parameters, are also discussed.
TiO2 Nanoparticle Addition into Molten Steel: From Lab Scale to Industrial Scale
Authors: Kaltzakorta Idurre , Callejo Lorena M. , Idoyaga Zuriñe
Published: May 2014

In this work, the design of a new technology for nanoparticle addition into molten steel that improves the mechanical properties of the material, as well as the upscale of the process, was pursued. The process was scaled from laboratory to industrial level starting from first experiments carried out in pure iron bath, in order to analyze the behavior of nanoparticles in molten metal environment, and finishing with the addition of nanoparticles into microalloyed steel bath as industrial trials. The first steps of the research were performed in the levitation furnace at Tecnalia R&I installations that can cast samples up to 1 kg, continuing with a high vacuum furnace with a capacity up to 35 Kg. By the end of the investigation, the process was scaled up to industrial level at Gerdau facilities.
Bendability and Microstructure of Direct Quenched Optim® 960QC
Authors: Kesti Vili , Kaijalainen A. , Väisänen A. , Järvenpää A. , Määttä A. , Arola A.M. , Mäntyjärvi K. , Ruoppa R.
Published: May 2014

Use of ultra-high-strength steels (UHSS) in weight critical constructions is an effective way to save energy and minimize carbon footprint in the end use. On the other hand, the demands for reducing manufacturing costs and energy consumption of the steelmaker are increasing. This has led to development of energy efficient direct quenching (DQ) steelmaking process as an alternative to the conventional quenched and tempered or thermomechanical rolling and accelerate cooled processes. Ruukki has employed thermomechanical rolling and direct quenching process (TM + DQ) for a novel type of ultra-high-strength strip and plate steels since 2001.
Advantages of the ultra-high-strength level (>900MPa) can be fully utilized only if fabricated properties are on a sufficient level. Bending is one of the most important workshop processes and a good bendability is essential for a structural steel. Hence, the metallurgy and bendability of Ruukki ́s TM + DQ strip steel Optim® 960QC have been investigated closely. It was found that by optimizing process parameters and chemical composition, a good combination of strength and ductility can be achieved by a modification of martensitic-bainitic microstructure. Despite of smaller total elongation, the bendability of Optim® 960QC is at least on the same level as on conventionally manufactured 960MPa steels. However, it is important to pay special attention to bending process (tool parameters, springback, bending force, material handling) when bending UHSS. It was also found that the bendability of Optim® 960QC can be significantly enhanced by local laser heat treatments or roll forming.
Mechanical and Corrosion Properties of a F138 Austenitic Stainless Steel after Deformation by Equal Channel Angular Pressing
Authors: Kliauga Andrea Madeira , Sordi V.L. , Ferrante Maurizio , Rovere C.A. , Curi S.E.
Published: May 2014

A F138 austenitic stainless steel was solution heat treated, deformed by equal-channel angular pressing (ECAP) at 25 and 300°C. The equivalent strain was ~0.7 per pass and the applied equivalent strain varied from 0.7 to 2.8. Microstructure evolution was observed by transmission electron microscopy (TEM) electron back-scattered diffraction (EBSD) and X –ray diffraction. Work hardening behavior was studied by making use of Kocks-Mecking plots and hardness measurements, the influence of deformation on corrosion resistance was evaluated recording anodic polarization curves in 0.9% NaCl solution.
Microstructure and Mechanical Properties of Extra High Strength Heavy Steel Plate for Bridge Application
Authors: Liu Dong Sheng , Yue Chong Xiang , Chen Huan De , Cheng Bing Gui
Published: May 2014

Key parameters for thermomechanical control process (TMCP) and integrated welding operations have been determined to industrialize extra high strength micro-alloyed low carbon SiMnCrMoNiCu steel plates for bridge applications. Confocal Scanning Microscope was used to make In-situ observation on austenite grain growth during reheating. A Gleeble 3800 thermomechanical simulator was employed to investigate transformation behavior of the TMCP conditioned austenite. Integrated industrial rolling trial was conducted to correlate the laboratory observations and commercial production of the plates. Microstructure factors affecting the toughness of the steel were analyzed. Submerged-Arc Welding (SMAW) trails were conducted and the structures and mechanical properties of the weld joints characterized. The representative plate with thickness of 60 mm consisted of acicular ferrite (AF) + refined polygonal ferrite (PF) + granular bainite (GB) across the entire thickness section exhibit yield strength (YS) greater than 560 MPa in transverse direction and excellent Charpy V Notch (CVN) impact toughness greater than 100 J at-40 °C in the parent metal and the weld joints. These provide useful integrated database for producing advanced high strength steel plates via TMCP.
Keywords: Thermo-Mechanical Control Process;Weathering Steel Plate for Bridge; Submerged-Arc Welding without Preheating
Three-Dimensional Approach to Observing Growth of Blocks and Packets in Fe-18Ni Maraging Steel
Authors: Morito Shigekazu , Yoshida Show , Hayamizu Rei , Hayashi Taisuke , Ohba Takuya , Terasaki Hidenori , Komizo Yuichi
Published: May 2014

The present study aims to clarify the development of blocks and packets in lath martensite in Fe–18Ni maraging steel using three-dimensional observations. The specimens were step-quenched in order to clarify the sequential development of the three-dimensional morphology in a prior austenite grain. In a prior austenite grain, we found that five independent packets formed during the early stage of martensitic transformation. Four of the packets exist along the prior austenite grain boundaries and one packet grows from the boundary edge into the prior austenite grain. Each packet consists of a single block, although the fraction of martensitic transformation is 50.6%. The observed rules of the block-selection are as follows: (1) the blocks have near Kurdjumov–Sachs orientation relationship with adjacent austenite grains and elongated directions of the laths are parallel to adjacent grain boundaries and (2) transformation shear directions of the laths are parallel to adjacent grain boundaries.
Fretting Fatigue Behaviour of 12-Cr Steels and Strength Prediction
Authors: Jayaprakash Murugesan , Mutoh Yoshiharu
Published: May 2014

In the present study fretting fatigue behaviour of 12-Cr steels at 300°C has been investigated under three different contact pressures. For comparisons fretting fatigue behaviour of 12-Cr steels at room temperature has also been investigated. The result showed that with an increase in contact pressure and temperature, the fretting fatigue significantly reduces. Finite element analyses were carried out to evaluate the stress distribution (tangential stress and compressive stress) at the contact during fretting fatigue. Tangential stress range – compressive stress range diagram (TSR-CSR diagram) were constructed for 12-Cr steel at room temperature and at 300°C. Then, a generalized TSR-CSR diagram to predict fretting fatigue strength of 12-Cr steel regardless of contact pressure and temperature was constructed.
Effects of ALPS on Mechanical Property in Bainitic Steels
Authors: Nakai Kiyomichi , Konishi Sanae , Sakamoto Tatsuaki , Kobayashi Sengo
Published: May 2014

Aggregate of bainite laths with almost parallel slip systems between neighboring bainite laths, hereafter referred to as ALPS, has great effect on the improvement of mechanical properties in steels. Elongation increases remarkably with increasing the number of bainite laths within an ALPS. When a bainite lath begins to deform, the neighboring bainite lath also easily deforms to relax the deformation strain, because of good parallelism between their slip systems. Under the cooperative deformation of bainite laths, the area of interface between neighboring bainite laths increases during deformation. The increase in the area of interface between neighboring bainite laths suppresses localization of dislocations at the interface, that is, dislocation density per unit area of the interface between neighboring bainite laths hardly increases, resulting in the suppression of nucleation of cracks at the interface between neighboring bainite laths. Ductile fracture would occur along the boundary between ALPSs. It could be suggested that larger ALPS and/or ALPS consisting of large number of bainite laths induce larger elongation in steels.On the other hand, it has been reported that tensile strength increases in proportion to inverse of square root of d, the d being the average size of bainite laths [1]. In order to form fine bainite lath, dislocation network instead of inclusion in austenite was utilized as nucleation site for bainite lath. Great barriers to be overcome exist for the improvement of both strength and toughness. An idea for the improvement of both strength and toughness is shown in this study.
Low-Cycle Fatigue Behavior and Microstructural Evolution of the Fe–30Mn–4Si–2Al Alloy
Authors: Nikulin Ilya , Sawaguchi Takahiro , Ogawa Kazuyuki , Tsuzaki Kaneaki
Published: May 2014

Superior fatigue life of 8000 cycles at low-cycle fatigue with a total strain Δε=2% was found in the Fe–30Mn–4Si–2Al high-Mn alloy, as compared to Fe–30Mn–6Si–0Al and Fe–30Mn–3Si–3Al alloys with fatigue life of 2×103 cycles. Examination of microstructural evolution and cyclic hardening/softening behavior was shown that high fatigue resistance of Fe–30Mn–4Si–2Al alloy associated with delayed development of the deformation induced martensite and inhibited dislocation slip as compared to Fe–30Mn–6Si–0Al and Fe–30Mn–3Si–3Al alloys, respectively. Cyclic strain softening followed by secondary strain hardening was observed in the Fe–30Mn–4Si–2Al alloy after primary hardening. Primary hardening to about 40 cycles was associated with continuous increase in density of planar dislocations and the development of slip bands. The cyclic softening manifesting as the drop of the stress amplitude in the range of the cycles from 40 to 400 was accompanied by development of deformation induced ε-martensite in place of the slip bands. At the N>400 cycles further increase in the volume fraction of deformation ε-martensite leads to continuous hardening up to the failure. In the presentation we will discuss the details of microstructural evolution during LCF of the Fe–30Mn–4Si–2Al alloy.
Development of Hollow Iron Ore Agglomerate and its Characterization
Authors: Pramanik Susanta , Mitra Swapan Kumar
Published: May 2014

Blast Furnace remains to be one of main producers of molten iron. The secondary or alternate sources of producing molten iron have come in place and contribute around 30% of molten iron production in the world. Good iron ore reserves are fast depleting coupled with a huge amount of fines being produced during mining.
EBSD Study of the Microstructural Evolution during Hot Compression Testing of a Superduplex Steel
Authors: Primig Sophie , Ragger Katharina S. , Buchmayr Bruno
Published: May 2014

Superduplex steels exhibit a microstructure of approximately equivalent fractions of austenite and δ-ferrite. This structure combines a higher strength than austenitic steels with a higher toughness than ferritic steels and an excellent corrosion resistance. Superduplex steels can be processed by different routes such as casting, extrusion, rolling or forging and are applied in the chemical industry, oil production or paper manufacturing. It is well known that the two phases exhibit a different dynamic restoration behavior due to their differences in the stacking fault energy. The austenite grains are more likely to undergo discontinuous dynamic recrystallization while the δ-ferrite grains tend to strong dynamic recovery. Modern large area electron back scatter diffraction (EBSD) scans are a powerful technique to study the microstructural evolution of the individual phases during hot-forming of duplex steels. However, detailed EBSD studies explaining the flow behavior, influence of grain orientation and grain size modification during hot forming have not been carried out yet.
In the present investigation specimens of a S32750 superduplex steel were deformed in uniaxial compression with strain rates between 0.01 and 1 [s-1] to a true strain of 1 at temperatures between 1000 and 1300°C. The microstructures of the as-deformed specimens were examined by large area EBSD scans with particular attention to the characteristics of the individual phases as for example grain size and stored energy of the austenite grains or subgrain size and grain boundary character of the ferrite grains. The differences due to deformation temperature and strain rate are discussed.
Same-sex relationships: A 1st-century perspective
Authors: Loader William
Published: May 2014

Read in the light of other Jewish literature of the time, not least, Philo of Alexandria, Paul’s comments in Romans 1 about same-sex relations should be seen as a rhetorical ploy to gain a sympathetic hearing for his argument from the Roman recipients of his letter by appealing to common ground in deploring the sins of the Gentile world before turning to challenge them about the fact that all have sinned, and so need the good news of God’s righteousness revealed in Christ. Typically Paul’s focus is not just acts, but attitude and misdirected passions, which he sees as the result of misdirected and perverted understandings of God. Based on the Genesis creation stories, Paul assumes that all people are heterosexual and that the prohibitions of Leviticus should apply also to lesbian relations. Where these assumptions are not shared, Paul’s conclusions must be revisited in the light of informed compassion and responsible ethical insight.
An airborne assessment of atmospheric particulate emissions from the processing of Athabasca oil sands
Authors: Howell S. G. , Clarke A. D. , Freitag S. , McNaughton C. S. , Kapustin V. , Brekovskikh V. , Jimenez J.-L. , Cubison M. J.
Published: May 2014

Abstract. During the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign, two NASA research aircraft, a DC-8 and a P-3B, were outfitted with extensive trace gas (the DC-8) and aerosol (both aircraft) instrumentation. Each aircraft spent about a half hour sampling air around the oil sands mining and upgrading facilities near Ft. McMurray, Alberta, Canada. The DC-8 circled the area, while the P-3B flew directly over the upgrading plants, sampling close to the exhaust stacks, then headed downwind to monitor the aerosol as it aged. At short range, the plume from the oil sands is a complex mosaic of freshly nucleated ultrafine particles from a SO2- and NO2-rich plume, soot and possibly fly ash from industrial processes, and dust from dirt roads and mining operations. Shortly downwind, organic aerosol appears in quantities that rival SO4, either as volatile organic vapors condense or as they react with the H2SO4. The DC-8 pattern allowed us to integrate total flux from the oil sands facilities within about a factor of 2 uncertainty that spanned values consistent with 2008 estimates from reported SO2 and NO2 emissions, though there is no reason to expect one flyby to represent average conditions. In contrast, CO fluxes exceeded reported regional emissions, due either to variability in production or sources missing from the emissions inventory. The conversion rate of SO2 to aerosol SO4 of ~6% per hour is consistent with earlier reports, though OH concentrations are insufficient to accomplish this. Other oxidation pathways must be active. Altogether, organic aerosol and black carbon emissions from the oil sands operations are small compared with annual forest fire emissions in Canada. The oil sands do contribute significant sulfate and exceed fire production of SO2 by an order of magnitude.
Primary and secondary biomass burning aerosols determined by proton nuclear magnetic resonance (1H-NMR) spectroscopy during the 2008 EUCAARI campaign in the Po Valley (Italy)
Authors: Paglione M. , Saarikoski S. , Carbone S. , Hillamo R. , Facchini M. C. , Finessi E. , Giulianelli L. , Carbone C. , Fuzzi S. , Moretti F. , Tagliavini E. , Swietlicki E. , Eriksson Stenström K. , Prévôt A. S. H. , Massoli P. , Canaragatna M. , Worsnop D. , Decesari S.
Published: May 2014

Abstract. Atmospheric organic aerosols are generally classified as primary and secondary (POA and SOA) according to their formation processes. An actual separation, however, is challenging when the timescales of emission and gas-to-particle formation overlap. The presence of SOA formation in biomass burning plumes leads to scientific questions about whether the oxidized fraction of biomass burning aerosol is rather of secondary or primary origin, as some studies would suggest, and about the chemical compositions of oxidized biomass burning POA and SOA. In this study, we apply nuclear magnetic resonance (NMR) spectroscopy to investigate the functional group composition of fresh and aged biomass burning aerosols during an intensive field campaign in the Po Valley, Italy. The campaign was part of the EUCAARI project and was held at the rural station of San Pietro Capofiume in spring 2008. Factor analysis applied to the set of NMR spectra was used to apportion the wood burning contribution and other organic carbon (OC) source contributions, including aliphatic amines. Our NMR results, referred to the polar, water-soluble fraction of OC, show that fresh wood burning particles are composed of polyols and aromatic compounds, with a sharp resemblance to wood burning POA produced in wood stoves, while aged samples are clearly depleted of alcohols and are enriched in aliphatic acids with a smaller contribution of aromatic compounds. The comparison with biomass burning organic aerosols (BBOA) determined by high-resolution aerosol mass spectrometry (HR-TOF-AMS) at the site shows only a partial overlap between NMR BB-POA and AMS BBOA, which can be explained by either the inability of BBOA to capture all BB-POA composition, especially the alcohol fraction, or the fact that BBOA account for insoluble organic compounds unmeasured by the NMR. Therefore, an unambiguous composition for biomass burning POA could not be derived from this study, with NMR analysis indicating a higher O / C ratio compared to that measured for AMS BBOA. The comparison between the two techniques substantially improves when adding factors tracing possible contributions from biomass burning SOA, showing that the operational definitions of biomass burning organic aerosols are more consistent between techniques when including more factors tracing chemical classes over a range of oxidation levels. Overall, the non-fossil total carbon fraction was 50–57%, depending on the assumptions about the 14C content of non-fossil carbon, and the fraction of organic carbon estimated to be oxidized organic aerosol (OOA) from HR-TOF-AMS measurements was 73–100% modern.
Impact of the aerosol type on HICO™ atmospheric correction in coastal waters
Authors: Bassani C. , Manzo C. , Braga F. , Bresciani M. , Giardino C. , Alberotanza L.
Published: May 2014

Abstract. The aim of this work is to evaluate the radiative impact of the aerosol type on the results of the atmospheric correction of HICO™ (Hyperspectral Imager for the Coastal Ocean) hyperspectral data. The reflectance was obtained by using the HICO@CRI (HICO ATmospherically Corrected Reflectance Imagery) algorithm, a physically-based atmospheric correction algorithm developed specifically for HICO™ data by adapting the vector version of the Second Simulation of a Satellite Signal in the Solar Spectrum (6SV) radiative transfer code. The HICO@CRI algorithm was applied on six HICO™ images acquired in the Northern part of the Mediterranean Basin, using the micro-physical properties measured with a CIMEL sun sky-radiometer at the Acqua Alta Oceanographic Tower (AAOT) AERONET site and the optical properties of the maritime, continental, and urban aerosol types provided by default by the 6SV. The results highlight that the aerosol type can improve the accuracy of the atmospheric correction. Indeed, the accuracy of the water reflectance retrieved from the available HICO™ data decreases in the sensor spectral domain, considering the AERONET micro-physical properties, of 30% using the urban aerosol type, of 20% using the continental type, and finally of less than 10% assuming a maritime type. Thus, the aerosol type has to be taken into consideration in the atmospheric correction of hyperspectral data over coastal environment, if water quality analysis has to be performed, because of the influence of aerosol type on the water reflectance.
Fine and coarse dust separation with polarization lidar
Authors: Mamouri R. E. , Ansmann A.
Published: May 2014

Abstract. The polarization-lidar photometer networking (POLIPHON) method for separating dust and non-dust aerosol backscatter and extinction, volume, and mass concentration is extended to allow for a height-resolved separation of fine-mode and coarse-mode dust properties in addition. The method is applied to a period with complex aerosol layering of fine-mode background dust from Turkey and Arabian desert dust from Syria. The observation was performed at the combined European Aerosol Research Lidar Network (EARLINET) and Aerosol Robotic Network (AERONET) site of Limassol (34.7° N, 33° E), Cyprus, in September 2011. The dust profiling methodology and case studies are presented. Consistency between the column-integrated optical properties obtained with sun/sky photometer and the respective results derived by means of the new lidar-based method corroborate the applicability of the extended POLIPHON version.
Temperature data acquired from the DOI/GTN-P Deep Borehole Array on the Arctic Slope of Alaska, 1973–2013
Authors: Clow G. D.
Published: May 2014

Abstract. A homogeneous set of temperature measurements obtained from the DOI/GTN-P Deep Borehole Array between 1973 and 2013 is presented; DOI/GTN-P is the US Department of the Interior contribution to the Global Terrestrial Network for Permafrost (GTN-P). The 23-element array is located on the Arctic Slope of Alaska, a region of cold continuous permafrost. Most of the monitoring wells are situated on the Arctic coastal plain between the Brooks Range and the Arctic Ocean, while others are in the foothills to the south. The data represent the true temperatures in the wellbores and surrounding rocks at the time of the measurements; they have not been corrected to remove the thermal disturbance caused by drilling the wells. With a few exceptions, the drilling disturbance is estimated to have been on the order of 0.1 K or less by 1989. Thus, most of the temperature measurements acquired during the last 25 yr are little affected by the drilling disturbance. The data contribute to ongoing efforts to monitor changes in the thermal state of permafrost in both hemispheres by the Global Terrestrial Network for Permafrost, one of the primary subnetworks of the Global Terrestrial Observing System (GTOS). The data will also be useful for refining our basic understanding of the physical conditions in permafrost in Arctic Alaska, as well as providing important information for validating predictive models used for climate impact assessments. The processed data are available from the Advanced Cooperative Arctic Data and Information Service (ACADIS) repository at doi:10.5065/D6N014HK.
A fully coupled 3-D ice-sheet – sea-level model: algorithm and applications
Authors: de Boer B. , Stocchi P. , van de Wal R. S. W.
Published: May 2014

Abstract. Relative sea-level variations during the late Pleistocene cannot be reconstructed regardless of the estimates of ice-volume fluctuations. For the latter, however, the knowledge of regional and global relative sea-level variations is necessary. Overcoming this problem of circularity demands a fully coupled system where ice sheets and sea level vary consistently in space and time and dynamically affect each other. Here we present results for the past 410 000 years (410 kyr) from the coupling of a set of 3-D ice-sheet-shelf models to a global sea-level model based on the solution of gravitationally self-consistent sea-level equation. The sea-level model incorporates all the Glacial Isostatic Adjustment feedbacks for a Maxwell viscoelastic and rotating Earth model with variable coastlines. Ice volume is computed with four 3-D ice-sheet-shelf models for North America, Eurasia, Greenland and Antarctica. With an inverse approach, ice volume and temperature are derived from a benthic δ18O stacked record. The ice-sheet thickness variations are then forwarded to the sea-level model to compute the bedrock deformation, the geoid and the relative sea-level change. The latter are used to generate the new topographies for the next time step, which are forwarded to the ice-sheet models. To quantify the impact of relative sea-level variations on ice-volume evolution, we have performed coupled and uncoupled simulations. The largest differences of ice-sheet thickness change show up in the proximity of the ice-sheets edges, where relative sea-level change significantly departs from the ocean-averaged sea level variation.
Increasing flood exposure in the Netherlands: implications for risk financing
Authors: Jongman B. , Koks E. E. , Husby T. G. , Ward P. J.
Published: May 2014

Abstract. The effectiveness of disaster risk management and financing mechanisms depends on an accurate assessment of current and future hazard exposure. The increasing availability of detailed data offers policy makers and the insurance sector new opportunities to understand trends in risk, and to make informed decisions on ways to deal with these trends. In this paper we show how comprehensive property level information can be used for the assessment of exposure to flooding on a national scale, and how this information provides valuable input to discussions on possible risk financing practices. The case study used is the Netherlands, which is one of the countries most exposed to flooding globally, and which is currently undergoing a debate on strategies for the compensation of potential losses. Our results show that flood exposure has increased rapidly between 1960 and 2012, and that the growth of the building stock and its economic value in flood-prone areas has been higher than in non-flood-prone areas. We also find that property values in flood-prone areas are lower than those in non-flood-prone areas. We argue that the increase in the share of economic value located in potential flood-prone areas can have a negative effect on the feasibility of private insurance schemes in the Netherlands. The methodologies and results presented in this study are relevant for many regions around the world where the effects of rising flood exposure create a challenge for risk financing.
Brief Communication: Landslides triggered by the Ms = 7.0 Lushan earthquake, China
Authors: Chen X. L. , Yu L. , Wang M. M. , Lin C. X. , Liu C. G. , Li J. Y.
Published: May 2014

Abstract. Earthquake-triggered landslides have drawn much attention around the world because of the severe hazards they pose. The 20 April 2013 Ms = 7.0 Lushan Earthquake, which occurred in the Longmen Shan region in Sichuan province, China, triggered more than 1000 landslides throughout an area of about 2200 km2, and completely blocked many roads and exacerbated overall transportation problems in the mountainous terrain. Preliminary landslide inventory is complied immediately following the earthquake, mainly based on the high-resolution remote sensing images. At the same time, the distribution of these landslides is statistically investigated to determine how the occurrence of landslides correlates with distance from the earthquake epicenter, slope steepness, seismic intensity and rock type. Statistic analysis is conducted using landslide point density (LPD), which is defined as the number of landslides per square kilometer. It is found that LPD has a strong positive correlation with slope gradients and a negative-exponential decline with the distance from the epicenter. The higher LPD values occur in younger strata systems like Quaternary and Tertiary sediments in the study area. Spatially, the triggered landslides are controlled by the causative faults and mainly concentrated around the epicenter. All the landslides are located within the area with seismic intensity ≥ VII and in line with seismic intensity. Generally, LPD value decreases with increasing distance from the epicenter, and sometimes landslides are densely distributed along the roads in the mountainous region. Also, this study reveals that the empirical relationship between distance and seismic magnitude is more suitable for estimating the landslide concentration area during the Lushan earthquake compared to other methods.
Real-scale investigation of the kinematic response of a rockfall protection embankment
Authors: Lambert S. , Heymann A. , Gotteland P. , Nicot F.
Published: May 2014

Abstract. This paper addresses the response of rockfall protection embankments when exposed to a rock impact. For this purpose, real-scale impact experiments were conducted with impact energies ranging from 200 to 2200 kJ. The structure was composed of a 4 m high cellular wall leaned against a levee. The wall was a double-layer sandwich made from gabion cages filled with either stones or a sand–schredded-tyre mixture. For the first time, sensors were placed in different locations within the structure to measure real-time accelerations and displacements. The test conditions, measurement methods and results are presented in detail. The structure's response is discussed in a descriptive and phenomenological approach and compared with previous real-scale experiments on other types of embankments.