Jul 01, 2002 · PDF | Recent progress in grain refinement of steels was overviewed. After energetic research works since middle 1990's including big national Ultrafine grained steels managing both high strength In case of commercial steels, the champion value has been 5 µm in the steel plate thermomechanically processed by so-called controlled rolling . On the other hand, it has become recently possible to fabricate the steels with ultrafine grained (UFG) structures of which mean grain size is smaller than 1 m, at least in laboratory scales .
May 11, 2018 · The effect of shot peening (SP) on microstructure and hardness of ultrafine-grained (UFG) low-alloy steel was investigated. With increasing shot-peening time from 0.5 to 1.5 h, grain size of UFG low-alloy steel decreases from 400 to 280 nm at surface whilst that of the layer with a depth of 160 m decreases from (230 ± 15) to (75 ± 5) nm.ULTRAFINE GRAINED STEELS BY ADVANCED STRAIN INDUCED DYNAMIC TRANSFORMATION AND ULTRAFINE SURFACE GRAINED STEEL One of the objectives of this project was to obtain ultra fine surface grained steels for plain and microalloyed low-C steels (0.05-0.1%C). The possibility of making microstructures in which bands of Ultra Fine Ferrite (UFF) grains act asUltra Fine-Grained 6wt% Manganese TRIP Steel | Scientific.NetUltra-fine grained TRIP steels (UFG-TRIP) containing 6wt%Mn were produced by intercritical annealing. An ultra-fine grained microstructure with a grain size less than 1m was obtained. The formation mechanism of the high volume fraction of retained austenite was investigated by dilatometry, XRD and magnetic saturation. The fraction of retained austenite was strongly dependent on the annealing ultrafine grained steels researchgate
The phenomenon of ultra-fine grain refinement effect by the existing precipitates of nanometer size in the steel produced by using thin slab casting and rolling (TSCR) has been discovered and analyzed. The theory of deformation induced precipitation and medium temperature phase transformation control for bainitic steels has been proposed.Ultra-Fine-Grained Steel: Fracture Toughness (Crack-Tip ultrafine grained steels researchgateH. Qiu, R. Ito, K. Hiraoka, Role of grain size on the strength and ductile-brittle transition temperature in the dual-sized ferrite region of the heat-affected zone of ultra-fine grained steel. Mater. Sci. Eng. A 435436, 648652 (2006) CrossRef Google ScholarUltrafine grain effect on pearlitic transformation in ultrafine grained steels researchgatePearlitic transformation in an ultrafine-grained (UFG) hypereutectoid steel was investigated. The steel was a plain carbon steel containing 1.0 wt% C and very few other elements. The UFG samples were prepared by thermomechanical treatment, and an average grain size of approximately 1
Abstract. Ultrafine-grained microstructures can be developed in a variety of alloy steels by coldworking followed by annealing in the + region. Because the annealing temperatures are relatively low and the recrystallized structure is two-phase, grain growth is restricted.ultra fine grained steels - LinkedIn SlideShareDec 04, 2010 · R. Song, D. Ponge, D. Raabe: ScriptaMaterialia 52 (2005) 1075-1080, Improvement of the work hardening rate of ultrafine grained steels through second phase particles 37. R. Song, D. Ponge, D. Raabe: ISIJ International 45 (2005) 1721-1726, Influence of Mn Content on the Microstructure and Mechanical Properties of Ultrafine Grained C-Mn Steels 38. R.Corrosion Behavior of Ultrafine Grained Austenitic ultrafine grained steels researchgateUltrafine grained AISI 304 steel was produced by low temperature recrystallization after subzero working, and the corrosion behavior of these steels was investigated in various corrosive environments. The general corrosion rate increased with decreasing grain diameter. On the other hand, the resistance to intergranular corrosion, pitting ultrafine grained steels researchgate
The mechanical properties of these dual phase steels were compared, and the response of the ultrafine-grained steel (1.2 um) to aging at 170 °C was investigated. The deformation and fracture mechanisms were studied based on microstructure observations using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD).Deformation and fracture in fine- and ultrafine-grained ultrafine grained steels researchgateThe mechanical properties of these dual phase steels were compared, and the response of the ultrafine-grained steel (1.2 um) to aging at 170 °C was investigated. The deformation and fracture mechanisms were studied based on microstructure observations using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD).Effect of Cyclic Thermal Process on Ultrafine Grain ultrafine grained steels researchgateOct 27, 2009 · The microstructural study by transmission electron microscope of the material after the cyclic thermal process showed formation of nanostructure or ultrafine grain austenite. The tensile testing of the ultrafine-grained austenitic stainless steel showed a yield strength 4 to 6 times higher in comparison to its coarse-grained counterpart.
Effect of Manganese on Grain Size Stability and Hardenability in Ultrafine-Grained Dual-Phase Steels For this project two plain carbon steels with varying manganese content (0.87 wt pct and 1.63 wt pct) were refined to approximately 1 um by large strain warm deformation and subsequently subjected to intercritical annealing to produce an ultrafine grained steels researchgateEffect of Manganese on Grain Size Stability and ultrafine grained steels researchgateEffect of Manganese on Grain Size Stability and Hardenability in Ultrafine-Grained Dual-Phase Steels For this project two plain carbon steels with varying manganese content (0.87 wt pct and 1.63 wt pct) were refined to approximately 1 um by large strain warm deformation and subsequently subjected to intercritical annealing to produce an ultrafine grained steels researchgateFriction Stir Welding of Ultrafine Grained TWIP Steelsteel with a conventional grain size is also shown for comparison. The base metal of the ultrafine grained TWIP steel shows high strength and adequate uniform elongation (35%), although it was reported that the ultrafine grained interstitial free (IF) steels and aluminums have limited ductility with ultimate high strength .
May 23, 2008 · Materials are typically ductile at higher temperatures and become brittle at lower temperatures. In contrast to the typical ductile-to-brittle transition behavior of body-centered cubic (bcc) steels, we observed an inverse temperature dependence of toughness in an ultrahigh-strength bcc steel with an ultrafine elongated ferrite grain structure that was processed by a thermomechanical MECHANICAL PROPERTIES OF AN ULTRAFINE GRAINED Comparison of the mechanical properties between the conventional and the ultrafine grained steels Fig. 2 shows the tensile properties of the conventional and the ultrafine grained steels at room temperature. The decrease in grain size from 6.8 µm to 1.3 µm leads to an increase in strength (especially of the lower yield stress) and Lüders ultrafine grained steels researchgateMECHANICAL PROPERTIES OF AN ULTRAFINE GRAINED Comparison of the mechanical properties between the conventional and the ultrafine grained steels Fig. 2 shows the tensile properties of the conventional and the ultrafine grained steels at room temperature. The decrease in grain size from 6.8 µm to 1.3 µm leads to an increase in strength (especially of the lower yield stress) and Lüders ultrafine grained steels researchgate
Jan 24, 2018 · A eutectoid steel with an ultrafine-grained ferrite () + submicron/Nano-cementite particle () structure was formed by combining warm deformation of martensite to a strain of 0.36 at 0.1 s 1 at 500 °C with subsequent annealing at 500 °C for 6 h.The characteristics of the microstructure were investigated by means of a scanning electronic microscope and transmission electron microscope ultrafine grained steels researchgateMicrostructure and Fatigue of Ultrafine-Grained Ferritic ultrafine grained steels researchgateSpecific features of the ultrafine-grained structure determined by the X-ray diffraction and transmission electron microscopy studies were used for estimation of dispersion hardening in the ultrafine grained steels researchgateNumerical Investigations on Residual Stress in Laser ultrafine grained steels researchgateThe samples of ultrafine-grained steel were provided by Angang Steel Company Limited. The mechanical properties of the plate of AN420s-grade steel with dimensions of 60 mm × 30 mm × 8 mm were obtained through an experimental tension test using a SUNS UTM5000 electronic tensile testing machine under an ambient temperature of about 0°C.
Tensile properties and work hardening behaviors of ultrafine grained carbon steel and pure iron processed by warm high pressure torsion Using automated crystal-orientation mapping (ACOM) in TEM, we have shown the formation of an ultrafine grained (UFG) structure with predominantly (>90%) high angle grain boundaries in C45 steel and Armco iron after high pressure torsion (HPT) at 350 °C.Transmission X ray diffraction characterization of ultrafine grained steels researchgateIn the present study, transmission X ray diffraction characterization of volume fraction of deformation induced martensite in metastable austenitic stainless steels viz. 301 and 304 SS, as a function of rolling reductions at 77 K has been reported.Ultra-Fine Grained Steels | Request PDF - researchgate.netX80 pipeline steel produced by TMCP has high strength and high toughness with ultrafine grain microstructure. The microstructure coarsens and the toughness worsens at the coarse grained
Equal channel angular pressing of low-carbon steel produces an ultrafine-grained microstructure with an average (sub-)grain size of 325 nm and both coarse and fine carbides, a microhardness of 330 ultrafine grained steels researchgateUltrafine Grained HSLA Steels for Cold Forming | Request PDFThe industrial level production of ultrafine grained (or ultrafine ferrite) ferrous alloys was investigated through three examples of steels that complied with the EN 10149-2 Euronorm and were ultrafine grained steels researchgate