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Statistical Analysis of Fatigue Crack Growth Behavior for Grade B Cast Steel
En savoir plusPublication year: 2010 Source: Materials & Design, In Press, Accepted Manuscript, Available online 8 October 2010 W., Li , T., Sakai , Q., Li , P., Wang Tests for fatigue crack growth rate (FCGR) and crack-tip opening displacement (CTOD) were performed to clarify the fatigue crack growth behavior of a railway grade B cast steel. The threshold values of this steel with specific survival probabilities are evaluated, in which the mean value is 8.3516MPam1/2, very similar to the experimental value, about 8.7279MPam1/2. Under the conditions of plane strain and small-scale yielding, the values of fracture toughness for this steel with specific survival probabilities are converted from the corresponding critical CTOD values, in which the mean value is about 138.4256 MPam1/2. In consideration of the inherent variability of...
Date : 20/10/2010
Effects of stress on radiation hardening and microstructural evolution in A533B steel
En savoir plusPublication year: 2010 Source: Journal of Nuclear Materials, In Press, Accepted Manuscript, Available online 8 October 2010 K., Fujii , K., Fukuya , R., Kasada , A., Kimura , T., Ohkubo Bent specimens of A533B steel (0.16 wt% Cu) were irradiated at 290°C to 1 dpa with 6.4 MeV Fe3+ ions. Calculated tensile stresses at the irradiated surface were set to 0, 250, 500 and 750 MPa. The specimens were subjected to hardness measurements, transmission electron microscopy (TEM) observations and three-dimensional atom probe (3DAP) analysis. The radiation-induced hardening decreased with increasing stress to 500 MPa which was near the yield strength. TEM and 3DAP results showed that well-defined dislocation loops and solute clusters were formed. The diameter of dislocation loops increased and the number density decreased when the stress was applied,...
Date : 20/10/2010
Strength enhancement of autocompleting medium and high carbon steels friction welded joints
En savoir plusPublication year: 2010 Source: Journal of Materials Processing Technology, In Press, Accepted Manuscript, Available online 8 October 2010 M., Kimura , D., Utsumi , M., Kusaka , K., Kaizu An autocompleting friction welding method, which was developed by the authors, is to weld with using a rotating insert piece set between fixed workpieces. The conditions to enhance the strength of the welded joint in an autocompleting friction welding method which involves a rotating insert between the fixed workpieces were determined. The weld faying surface of the fixed specimen had a 10mm diameter. When MCS joint was made at an insert thickness of 4mm through a friction pressure of 36 MPa, it did not achieve 100% joint efficiency because the weld interfaces were not completely joined. MCS joint had 100%...
Date : 20/10/2010
Calibration of constitutive models of steel beams subject to local buckling by using Digital Image Correlation
En savoir plusPublication year: 2010 Source: European Journal of Mechanics - A/Solids, In Press, Accepted Manuscript, Available online 8 October 2010 Francois, Hild , Stephane, Roux , Nestor, Guerrero , Maria Eugenia, Marante , Julio, Florez-Lopez It is proposed to identify the behavior of steel beams prior to and after the inception of local buckling by using Digital Image Correlation. Full field measurements are used to evaluate kinematic and static fields for determining constitutive laws. It enables for the detection of local buckling inception and the evaluation of the postbuckled behavior. Constitutive models are tuned by using measured Euler-Bernoulli kinematics.
Date : 20/10/2010
Steam oxidation resistance of Ni-aluminide/Fe
En savoir plusPublication year: 2010 Source: Corrosion Science, In Press, Accepted Manuscript, Available online 8 October 2010 Z.D., Xiang , D., Zeng , C.Y., Zhu , S.R., Rose , P.K., Datta Steam oxidation resistance and thermal stability were studied at 650 °C for a coating with an outer Ni2Al3 layer and an inner Fe2Al5 layer formed on P92 steel surface. The parabolic rate law of oxidation was obeyed only in less than 2000 h with positive deviations occurring at longer oxidation times. The outer layer of the coating was transformed to NiAl during oxidation, but it remained stable once it was formed. The mechanisms for the enhanced thermal stability were discussed and a simple approach to enhancing the lifetime of the coating was proposed.
Date : 20/10/2010
Xanthione: A new and effective corrosion inhibitor for mild steel in sulphuric acid solution
En savoir plusPublication year: 2010 Source: Arabian Journal of Chemistry, In Press, Accepted Manuscript, Available online 8 October 2010 N.O., Obi-Egbedi , I.B., Obot The adsorption and inhibition effect of xanthione (XION) on mild steel in 0.5 M H2SO4 at 303-333 K was studied using gravimetric and UV-Visible spectrophotometric methods. The results obtained show that XION acts as an effective corrosion inhibitor for mild steel in sulphuric acid and inhibition efficiency reaches 98.0% at a very low inhibitor concentration of 10 × 10µM. Inhibition efficiency was found to increase with increase in XION concentration but decreased with temperature suggesting physical adsorption mechanism although chemisorption also plays a part. Arrhenius law and its transition equation lead to estimate of the activation parameters of the corrosion...
Date : 20/10/2010
The effect of laser remelting in the formation of tunable nano porous Mn structures on mild steel substrates
En savoir plusPublication year: 2010 Source: Applied Surface Science, In Press, Accepted Manuscript, Available online 8 October 2010 Chang-sheng, Dong , Yu, Gu , Min-lin, Zhong , Lin, Li , Ming-xing, Ma , ... Nanoporous manganese was fabricated by a three-step process involving high power laser cladding of a homogeneous Cu40Mn60 alloy coatings onto a mild steel substrate, laser remelting for tuning the grain size and the composition homogeneity followed by selectively electrochemical de-alloying for removal of Cu element and formation of nanoporous Mn. The microstructure and homogeneity of the precursor Cu40Mn60 alloys have a significant influence on the evolution of nanopores during selectively electrochemical de-alloying. Laser remelting can significantly refine the microstructure. The second dendrite arm spacing decreases with increasing of laser remelting scanning speed. A SDAS of 1.17µm was obtained at the...
Date : 20/10/2010
Improvement of the cavitation erosion resistance of UNS S31803 stainless steel by duplex treatment
En savoir plusPublication year: 2010 Source: Surface and Coatings Technology, In Press, Accepted Manuscript, Available online 10 October 2010 D.H., Mesa , C.E., Pinedo , A.P., Tschiptschin A Duplex surface treatment consisting of High Temperature Gas Nitriding (HTGN) followed by Low Temperature Plasma Nitriding (LTPN) was carried out in an UNS S31803 duplex stainless steel. The HTGN treatment was intended to produce a relatively thick and hard fully austenitic layer giving mechanical support to the thinner and much harder expanded austenite layer. HTGN was performed at 1200°C for 3hours, in a 0.1MPaN2 atmosphere while LTPN, was carried out in a 75% N2+25% H2 atmosphere, at 400°C for 12hours, under a 250Pa pressure, and 450V. An expanded austenite ?N layer, 2.3µm thick, 1500 HV0.025 hard, was formed on...
Date : 20/10/2010
Comparative numerical studies of projectile impacts on plain and steel
En savoir plusPublication year: 2010 Source: International Journal of Impact Engineering, In Press, Accepted Manuscript, Available online 10 October 2010 Ulrika, Nyström , Kent, Gylltoft The enhanced energy absorption characteristics of fibre-reinforced concrete, compared to plain concrete, has in experimentally studies been shown to improve the projectile resistance and motivate its increased usage in protective structures. However, the high cost of undertaking experiments and the high parameter variation and dependency of the experimental setups and results, respectively, make it difficult to draw generic conclusions of how the addition and increased amount of fibres affects the local damage caused by projectile impact, which motivates the use of numerical simulations to study this. The numerical hydrocode AUTODYN was used in a qualitative study of how the addition...
Date : 20/10/2010
Competition Mechanism between Microstructure Type and Inclusion Level in Determining VHCF Behavior of Bainite/Martensite Dual Phase Steels
En savoir plusPublication year: 2010 Source: International Journal of Fatigue, In Press, Accepted Manuscript, Available online 10 October 2010 Y., Yu , J.L., Gu , F.L., Shou , L., Xu , B.Z., Bai , ... The very high cycle fatigue (VHCF) behaviors of Bainite/Martensite (B/M) dual phase high-strength low-alloy (HSLA) steels were investigated using ultrasonic fatigue technology. Both non-inclusion and inclusion induced crack initiations occurred in the designed steels under VHCF test. It is shown that the VHCF behaviors are determined by the competition between the inclusion level of steels and the microstructure type consisted of different kinds of phases, microstructure homogeneity and refinement degree. The physical and chemical metallurgy methods could be coordinated to achieve excellent VHCF properties of high strength steels through microstructure optimization and inclusion size reduction.
Date : 20/10/2010
