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Steel Sheets (steel + sheet)

Distribution by Scientific Domains
Polymers and Materials Science88%

Selected Abstracts

Assessment of a Micro,Macro Modeling of the Bending and Unbending of Multiphase Steel Sheets,

ADVANCED ENGINEERING MATERIALS, Issue 3 2009
Laurent Delannay
Dual phase steels and TRIP steels demonstrate complex mechanical responses whenever metal forming operations involve load reversals. The present study addresses this phenomenon using an experimental set-up which ensures pure bending and unbending of thin sheets. The proposed incremental mean-field theory produces valid predictions of the transient mechanical responses by accounting for the kinematical hardening of individual phases as well as the phase partitioning of plastic strain. [source]

Experimental validation of the wavefield transform of electromagnetic fields

GEOPHYSICAL PROSPECTING, Issue 5 2002
Kaushik Das
The wavefield transform is a mathematical technique for transforming low-frequency electromagnetic (EM) signals to a non-diffusive wave domain. The ray approximation is valid in the transform space and this makes traveltime tomography for 3D mapping of the electrical conductivity distribution in the subsurface possible. The transform, however, imposes stringent frequency bandwidth and signal-to-noise ratio requirements on the data. Here we discuss a laboratory scale experiment designed to collect transform quality EM data, and to demonstrate the practical feasibility of transforming these data to the wavefield domain. We have used the scalable nature of EM fields to design a time-domain experiment using graphite blocks to simulate realistic field conditions while leaving the time scale undisturbed. The spatial dimensions have been scaled down by a factor of a thousand by scaling conductivity up by a factor of a million. The graphite blocks have two holes drilled into them to carry out cross-well and borehole-to-surface experiments. Steel sheets have been inserted between the blocks to simulate a conductive layer. Our experiments show that accurate EM data can be recorded on a laboratory scale model even when the scaling of some features, such as drill-hole diameters, is not maintained. More importantly, the time-domain EM data recorded in cross-well and surface-to-borehole modes can be usefully and accurately transformed to the wavefield domain. The observed wavefield propagation delay is proportional to the direct distance between the transmitter and receiver in a homogeneous medium. In a layered medium, data accuracy is reduced and, hence, our results are not so conclusive. On the basis of the experimental results we conclude that the wavefield transform could constitute a valid approach to the interpretation of accurate, undistorted time-domain data if further improvement in the transform can be realized. [source]

Recrystallization and Texture in a Ferritic Stainless Steel: an EBSD Study,

ADVANCED ENGINEERING MATERIALS, Issue 8 2003
C.W. Sinclair
The recrystallization behavior of laboratory-processed AISI409 ferritic stainless steel sheet has been studied with a focus on texture inhomogeneity and "sluggish" recrystallization kinetics, mainly using EBSD in the scanning electron microscope. Pronounced texture gradients were observed in some grain orientations (see Figure for a TEM image of the , versus ,-grain border region) and correlated to the deformation-induced substructure. The strong pinning of some boundaries has been linked not only to textural effects, but also to the precipitation of fine titanium carbonitrides. [source]

Compositionally Graded Aluminum Oxide Coatings on Stainless Steel Using Laser Processing

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2007
Partha P. Bandyopadhyay
A 1.5 mm thick fully dense alumina coating with a composition gradient from 100% Ni,20 wt% Cr at the substrate to 100% alumina on top has been developed on a 316 stainless steel sheet using Laser Engineered Net Shaping (LENSÔ). The gradient coatings showed hardness in the range of 1800,2000 Hv, one of the highest reported so far due to high-density layers. During laser deposition, ,-Al2O3 found to grow along the deposition direction with coarse columnar structure. The inherent advantage of this approach is to control simultaneously both location and composition leading to better interfacial properties of coatings. [source]

Hot water acid-resistant enamels for sheet steel

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 1 2010
A. S. Kassem
Abstract Several enamel frit recipes were formulated for direct-on application on sheet steel. Their suitability as hot water and acid-resistant coatings were investigated. DTA analyses were performed on raw batches to follow up physico-chemical changes occurring on firing. Then batches with different recipe compositions were fritted and mixed with mill additions. These were then tested for thermal expansion and the corresponding linear coefficients as well as glass transition temperatures and softening points were obtained. Also, the viscosity of molten frits was determined as a function of temperature. These frits were then applied on sheet steel and the following properties were investigated: resistance to hot water, acid resistance, surface gloss, and adherence to steel. It was found that recipe No. 4, containing no manganese dioxide and the highest amount of nickel oxide among all the suggested recipes, gave the best results. The optimum conditions for application on steel sheet were: firing at 850,°C for 5 min. [source]

Coupling of Forming Process and Fatigue Design Computations: A Local Approach

ADVANCED ENGINEERING MATERIALS, Issue 9 2009
Matteo Luca Facchinetti
The fatigue design of stamped parts is supposed to take into account for the forming process. In this paper, stamping of steel sheets is addressed by basic rules coming from elementary solid mechanics and plasticity. As an effective alternative to complex FE computations, such a pragmatic approach highlights how the forming process affects fatigue design and allows direct application in an industrial framework. [source]

Combined effect of strength & sheet thickness on fatigue behaviour of resistance spot welded joint

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 9 2010
S. GHOSH
ABSTRACT Fatigue performance of spot welded lap shear joint is primarily dependent on weld nugget size, sheet thickness and corresponding joint stiffness. Two automotive steel sheets having higher strength lower thickness and lower strength higher thickness are resistance spot welded with established optimum welding condition. The tensile-shear strength and fatigue strength of lap shear joint of the two automotive steel sheets are determined and compared. Experimental fatigue life of spot welded lap shear joint of each steel are compared with predicted fatigue lives using different stress intensity factor solutions for kinked crack and spot weld available in literature. Micrographs of fatigue fractured surfaces are examined to understand fracture micro-mechanisms. [source]

Study of influence of notch root radius on fracture behaviour of extra deep drawn steel sheets

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 12 2009
V. V. CHAUDHARI
ABSTRACT Fracture tests are carried out on extra deep drawn steel CT specimens containing notches with different values of notch root radius (,= 0.07,0.75 mm). Experimental findings clearly show a critical notch root radius (,c) below which the fracture toughness remains independent of , and above which it varies linearly with ,. The 3D finite element analysis shows that the location of maximum stress level causing crack initiation is in the vicinity of notch tip. The maximum stress level is independent of ,; however, its location is shifted away from notch tip along unbroken ligament length with increase in ,. [source]

A universal alternating immersion simulator for accelerated cyclic corrosion tests,

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2008
A. W. Hassel
A new device for performing accelerated cyclic immersion tests is described. The main achievement is to realise a high cycling rate without a proportional increase in the test duration. The device is also capable of performing tests according to EU ISO 11130 specification. A minimal invasive drying system is used that neither heats air nor sample and the flow rate is still low as to prevent a mechanical delamination of paints or loose corrosion products. A multiple sample set-up is realised that provides individual reference electrodes. The random access through a multiplexer allows individual investigation of the samples even by electrochemical impedance spectroscopy under immersion conditions. The device and its test principle are applicable in both industrial and laboratorial scale applications. Two application examples are given to demonstrate the versatility of the alternating immersion tester. One addresses the corrosion protection performance of different zinc-coated steel sheets; the other quantifies the patina formation kinetics of low-alloyed steels with weathering properties. [source]