Maximization of Strengthening Effect of Microscopic Morphology in Duplex Steels

2015 ◽  
pp. 541-555 ◽  
Author(s):  
Ikumu Watanabe ◽  
Gaku Nakamura ◽  
Kohei Yuge ◽  
Daigo Setoyama ◽  
Noritoshi Iwata
Keyword(s):  
Strengthening Effect ◽  
Microscopic Morphology ◽  
Duplex Steels

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

Local and global analysis of plasticity in ferritic-austenitic duplex steels

2001 ◽  
Vol 11 (PR5) ◽  
pp. Pr5-293-Pr5-300 ◽  
Author(s):  
V. V. Silberschmidt ◽  
M. Ortmayr ◽  
C. Messner ◽  
E. A. Werner
Keyword(s):  
Global Analysis ◽  
Duplex Steels

Numeric simulation of theα/γ-phase ratio of ferritic-austenitic duplex steels

2005 ◽  
Vol 96 (7) ◽  
pp. 749-752
Author(s):  
Michael Pohl ◽  
Murat Mola
Keyword(s):  
Phase Ratio ◽  
Numeric Simulation ◽  
Duplex Steels

scholarly journals ODS EUROFER Steel Strengthened by Y-(Ce, Hf, La, Sc, and Zr) Complex Oxides

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1148 ◽  
Author(s):  
Roman Husák ◽  
Hynek Hadraba ◽  
Zdeněk Chlup ◽  
Milan Heczko ◽  
Tomáš Kruml ◽  
...  
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Complex Oxides ◽  
Oxide Dispersion Strengthened ◽  
Interparticle Spacing ◽  
Oxide Dispersion ◽  
Strengthening Effect ◽  
Dispersion Strengthening ◽  
Doping Element ◽  
Average Grain Size

Oxide dispersion-strengthened (ODS) materials contain homogeneous dispersions of temperature-stable nano-oxides serving as obstacles for dislocations and further pinning of grain boundaries. The strategy for dispersion strengthening based on complex oxides (Y-Hf, -Zr, -Ce, -La) was developed in order to refine oxide dispersion to enhance the dispersion strengthening effect. In this work, the strengthening of EUROFER steel by complex oxides based on Y and elements of the IIIB group (lanthanum, scandium) and IVB group (cerium, hafnium, zirconium) was explored. Interparticle spacing as a dispersoid characteristic appeared to be an important factor in controlling the dispersion strengthening contribution to the yield strength of ODS EUROFER steels. The dispersoid size and average grain size of ODS EUROFER steel were altered in the ranges of 5–13 nm and 0.6–1.7 µm, respectively. Using this strategy, the yield strength of the prepared alloys varied between 550 MPa and 950 MPa depending on the doping element.

scholarly journals Effect of Sm Doping on the Microstructure, Mechanical Properties and Shape Memory Effect of Cu-13.0Al-4.0Ni Alloy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4007
Author(s):  
Qimeng Zhang ◽  
Bo Cui ◽  
Bin Sun ◽  
Xin Zhang ◽  
Zhizhong Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Strengthening Effect ◽  
Face Centered Cubic ◽  
Compressive Fracture ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Face Centered

The effects of rare earth element Sm on the microstructure, mechanical properties, and shape memory effect of the high temperature shape memory alloy, Cu-13.0Al-4.0Ni-xSm (x = 0, 0.2 and 0.5) (wt.%), are studied in this work. The results show that the Sm addition reduces the grain size of the Cu-13.0Al-4.0Ni alloy from millimeters to hundreds of microns. The microstructure of the Cu-13.0Al-4.0Ni-xSm alloys are composed of 18R and a face-centered cubic Sm-rich phase at room temperature. In addition, because the addition of the Sm element enhances the fine-grain strengthening effect, the mechanical properties and the shape memory effect of the Cu-13.0Al-4.0Ni alloy were greatly improved. When x = 0.5, the compressive fracture stress and the compressive fracture strain increased from 580 MPa, 10.5% to 1021 MPa, 14.8%, respectively. When the pre-strain is 10%, a reversible strain of 6.3% can be obtained for the Cu-13.0Al-4.0Ni-0.2Sm alloy.

Evolution of Microscopic Morphology and Surface Features of Cornstalk Torrefied with/without O2 Involving

2021 ◽  
pp. 1-9
Author(s):  
Qicheng Chen ◽  
Wei Han ◽  
Qiaomu Zhang ◽  
Weishan Liu ◽  
Nanhang Dong
Keyword(s):  
Surface Features ◽  
Microscopic Morphology

scholarly journals Activated Ductile CFRP NSMR Strengthening

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2821
Author(s):  
Jacob Wittrup Schmidt ◽  
Christian Overgaard Christensen ◽  
Per Goltermann ◽  
José Sena-Cruz
Keyword(s):  
Failure Modes ◽  
Elastic Response ◽  
Applied Theory ◽  
Strengthening Effect ◽  
The Novel ◽  
Near Surface ◽  
Linear Elastic ◽  
Near Surface Mounted ◽  
High Elongation ◽  
Strengthened Beam

Significant strengthening of concrete structures can be obtained when using adhesively-bonded carbon fiber-reinforced polymer (CFRP) systems. Challenges related to such strengthening methods are; however, the brittle concrete delamination failure, reduced warning, and the consequent inefficient use of the CFRP. A novel ductile near-surface mounted reinforcement (NSMR) CFRP strengthening system with a high CFRP utilization is introduced in this paper. It is hypothesized that the tailored ductile enclosure wedge (EW) end anchors, in combination with low E-modulus and high elongation adhesive, can provide significant strengthening and ductility control. Five concrete T-beams were strengthened using the novel system with a CFRP rod activation stress of approximately 980 MPa. The beam responses were compared to identical epoxy-bonded NSMR strengthened and un-strengthened beams. The linear elastic response was identical to the epoxy-bonded NSMR strengthened beam. In addition, the average deflection and yielding regimes were improved by 220% and 300% (average values), respectively, with an ultimate capacity comparable to the epoxy-bonded NSMR strengthened beam. Reproducible and predictable strengthening effect seems obtainable, where a good correlation between the results and applied theory was reached. The brittle failure modes were prevented, where concrete compression failure and frontal overload anchor failure were experienced when failure was initiated.

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