scholarly journals Influence of Inter-Pass Cooling on Microstructural Evolution and Plastic Deformation of Heavy EH47 Plates

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1686
Author(s):  
Junyu Wu ◽  
Bin Wang ◽  
Bingxing Wang ◽  
R. D. K. Misra ◽  
Zhaodong Wang
Keyword(s):  
Plastic Deformation ◽  
Grain Boundary ◽  
Microstructural Evolution ◽  
Volume Fraction ◽  
Uniform Elongation ◽  
Hexagonal Structure ◽  
Tensile Fracture ◽  
Boundary Area ◽  
Plastic Deformation Behavior ◽  
Deformation Pass

Herein, the influence of inter-pass cooling (IC) and conventional two-stage rolling (CTR), on microstructural evolution and plastic deformation behavior of ultra-heavy EH47 plates, is demonstrated. It is reported that the deformation amount and deformation rate, in every deformation pass during rough rolling, at 1/4- and 1/2-thickness of IC steel were higher than the CTR steel. The volume fraction of ferrite and acicular ferrite was 45% and 18%, at 1/4-thickness, and 35% and 50% at 1/2-thickness of IC steel, respectively, whereas the sum of both ferrite phases was smaller than 25% in the CTR steel. The austenite grain boundary area and high-angle grain boundary fraction in the IC steel were higher than the CTR steel. The high density of fine and shapeless pearlite has been observed in IC steel, whereas large-size carbides, with hexagonal structure, have been observed in CTR steel. Compared to the CTR steel, the density of precipitates was apparently lower in IC steel. Two kinds of Nb containing precipitates, such as (Ti, Nb)(C, N) and (Nb, Ti)C, were observed in the tested steels. Total ductility and uniform elongation of the IC steel were higher than the CTR steel. During the tensile process, the crack initiation energy and crack propagation energy of the IC steel were higher than the CTR steel. Moreover, the volume fraction of retained austenite (FCC) was reduced from 7.71% to 0.42% near the tensile fracture in IC steel at 1/4-thickness. In additon, the strain of synergetic plastic deformation of the IC steel was higher than the CTR steel. Meanwhile, compared to the CTR steel, the synergetic plastic deformation of the IC steel occurred at low stress after the yield point, which can be ascribed to the presence of fewer microcracks in the IC steel. Hence, a delayed fracture has been observed in the IC steel plate.

Atomistic Analysis of Nano-Scale Crystal Plasticity in Thin Metal Films

2004 ◽  
Vol 20 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Y.-L. Shen ◽  
R. W. Leger
Keyword(s):  
Plastic Deformation ◽  
Mechanical Response ◽  
Metal Films ◽  
Thin Metal ◽  
Tensile Fracture ◽  
Thin Metal Films ◽  
Free Standing ◽  
Nano Scale ◽  
Plastic Deformation Behavior ◽  
Defect Interactions

ABSTRACTNumerical simulations based on molecular statics are carried out to study nano-scale plastic deformation behavior in thin metal films. Particular attention is devoted to correlating the overall mechanical response and the underlying crystal defect mechanisms during mechanical loading. The simulations are within the two-dimensional framework involving pair molecular interactions in singlecrystal materials. Special modeling features are utilized for studying the formation of dislocations, interface characteristics, and defect interactions. Specific problems investigated in this work include: plastic deformation and tensile fracture in a free-standing film, interface-constrained plasticity in substrate-bonded films, and homogeneous nucleation of dislocations during nanoindentation.

Microstructure and Plastic Deformation in Unidirectionally Solidified NbSi2 (C40) /MoSi2 (C11b) Crystals

2000 ◽  
Vol 646 ◽  
Author(s):  
Takayoshi Nakano ◽  
Yasuhiro Nakai ◽  
Yukichi Umakoshi
Keyword(s):  
Heat Treatment ◽  
Plastic Deformation ◽  
Yield Stress ◽  
Volume Fraction ◽  
Lamellar Spacing ◽  
Compression Tests ◽  
High Fracture ◽  
Zone Method ◽  
Plastic Deformation Behavior ◽  
Single Set

ABSTRACTMicrostructure and plastic deformation behavior in duplex-phase silicides composed of the C40 and C11b phases were examined using pseudo-binary (Nb,Mo)Si2 crystals with a single set of lamellae. Single crystals of the C40 single-phase were grown from the master ingot with a composition of (Nb0.15Mo0.85)Si2 by a floating zone method and duplex-phase microstructure containing a single set of lamellae was obtained by subsequent heat treatment at 1400°C for no less than 6h. During the heat treatment, the C11b phase was precipitated from the C40 matrix by satisfying the crystallographic relationship of (0001)C40//(110)C11b, <1210]C40//[110]C11b and < [1010]C40//[001]C11b at the lamellar boundary, while randomly oriented C11b grains also appeared at further annealing. As a result, the duplex-phase silicides with a single set of lamellae contained the C40 phase with a single orientation and three variants of the C11b phase. The lamellar spacing and the volume fraction of their phases depended strongly on annealing time.In compression tests, yield stress and fracture strain of the duplex-phase silicides depended strongly on angle (φ) between the loading axis and lamellar boundaries, similar to TiAl-PST crystals. At φ=0°, specimens fractured just after showing high fracture stress even at 1400°C. In contrast, at φ=45° where shear deformation in the C11b phase of lamellae occurred parallel to lamellar boundaries, low yield stress and significant plastic strain were achieved at 1400°C.

Role of the Microstructure on the Deformation Behavior in Mg12ZnY with a Long-Period Stacking Ordered Structure

2008 ◽  
Vol 1128 ◽  
Author(s):  
Koji Hagihara ◽  
Naoyuki Yokotani ◽  
Akihito Kinoshita ◽  
Yuya Sugino ◽  
Hiroyuki Yamamoto ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Deformation Behavior ◽  
Hexagonal Structure ◽  
Rhombohedral Structure ◽  
Plastic Behavior ◽  
Long Period ◽  
Lpso Structure ◽  
Plastic Deformation Behavior ◽  
Deformation Modes

AbstractThe influence of a heat-treatment on the plastic deformation behavior in Mg12ZnY with a long-period stacking ordered (LPSO) structure was investigated by using crystals grown by the Bridgman method. Annealing of the crystal at 798 K for 3 days induced the change in the crystal structure of Mg12ZnY from the 18-fold rhombohedral structure (18R) to the 14-fold hexagonal structure (14H). The plastic behavior of those LPSO crystals showed a large variation depending on the loading axis in both crystals, because of the limitation of operative deformation modes in them. The change in the stacking sequence in the LPSO crystals did not show a large influence on the plastic deformation behavior at room temperature.

scholarly journals Plastic Deformation Behavior and Microstructural Evolution of Al-Core/Cu-Sheath Composites in Multi-pass Caliber Rolling

2014 ◽  
Vol 46 (1) ◽  
pp. 260-269 ◽  
Author(s):  
Jung Gi Kim ◽  
Marat I. Latypov ◽  
Dong Jun Lee ◽  
Ha-Guk Jeong ◽  
Jong Beom Lee ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Microstructural Evolution ◽  
Deformation Behavior ◽  
Plastic Deformation Behavior

Grain Boundary Area, Grain Boundary Curvature and Particle Pinning in an Al-1mass%Mn Alloy Containing Al6Mn Precipitates

2004 ◽  
Vol 467-470 ◽  
pp. 991-996 ◽  
Author(s):  
Paulo Rangel Rios ◽  
G.S. Fonseca
Keyword(s):  
Grain Boundary ◽  
Volume Fraction ◽  
Point Of View ◽  
Experimental Point ◽  
Experimental Measurements ◽  
Interface Area ◽  
Boundary Area ◽  
Boundary Curvature ◽  
Theory And Experiment ◽  
Good Agreement

The usual expression to calculate the limiting grain radius due to particle pinning is RL=ar/f, where r is the particle radius, f is the volume fraction of the particles, RL is the limiting grain radius and a is a constant equal to 1/6 according to Rios[Acta Metall. Vol. 35 (1987) p. 2805]. This form is not convenient for comparison with experimental measurements. In this work two alternative expressions are proposed: 1)SVL=3SVP where SV is the grain boundary area per unit of volume and SVP is the interface area per unit of volume and 2)H=SVP where H is the total grain boundary curvature. These expressions are compared with experimental measurements carried out in a high purity Al-1mass%Mn alloy containing Al6Mn precipitates annealed for 3600 s at temperatures ranging from 500 to 620 oC. Good agreement is obtained between theory and experiment. The relative merits and shortcomings of each expression are discussed in detail from a fundamental and experimental point of view. It is concluded that the first expression is probably the best choice for practical purposes.

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