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Influence of Nonmartensitic Transformation Products on Mechanical Properties of Tempered Martensite

Description: "The influence of nonmartensitic transformations products on the mechanical properties of tempered martensite is presented for samples of a SAE 4340 steel, partially isothermally transformed to specific high-temperature transformation products and quenched and tempered to hardness values of from 25 to 40 Rockwell C. The effects of upper bainite in amounts of 1,5, 10, 20 and 50 percent, of 5 percent ferrite, and of 5 percent pearlite on the tensile, impact, and fatigue properties are evaluated" … more
Date: December 1952
Creator: Hodge, J. M. & Lankford, W. T.
Partner: UNT Libraries Government Documents Department
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Martensite In CU-12.0% AL Alloy

Description: Thin foils suitable for transmission electron microscopy have been prepared from bulk specimens of Cu-12.0% Al alloy quenched from 800' C to produce martensite. The martensitic structure consists of long lenticular plates which are twinned on 20-50A scale. The twin planes in the martensite are shown to be [formula]. There is evidence that this structure is ordered as expected for a transformation from an ordered parent lattice. Experiments using a high temperature stage show that the decomposit… more
Date: April 1961
Creator: Thomas, G. & Huffstutler, M.C., Jr.
Partner: UNT Libraries Government Documents Department
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Unveiling the interplay of deformation mechanisms in a metastable high entropy alloy with tuned composition using synchrotron X-ray diffraction

Description: Article investigating the mechanical behavior of a metastable high entropy alloy (HEA) with composition Fe39-Mn20-Co20-Cr15-Si5-1Al (at%).
Date: January 15, 2022
Creator: Polatidis, E.; Shukla, S.; Čapek, J.; Van Petegem, S.; Casati, N. & Mishra, R. S.
Partner: UNT College of Engineering
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Texture evolution in thin-sheets on AISI 301 metastable stainless steel under dynamic loading

Description: The evolution of texture in thin sheets of metastable austenitic stainless steel AISI 301 is affected by external conditions such as loading rate and temperature, by inhomogeneous deformation phenomena such as twinning and shear band formation, and by the concurent strain induced phase transformation of the retained austenitc ({gamma}) into martensite ({alpha}). The present paper describes texture measurements on different gauges of AISI 301 prior and after uniaxial stretching under different c… more
Date: May 8, 1995
Creator: Kim, K. Y.; Kozaczek, K.; Kulkarni, S. M.; Bastias, P. C. & Hahn, G. T.
Partner: UNT Libraries Government Documents Department
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Reports of the measurement of elastic properties of 51XX series steels for the heat treatment distortion project

Description: We have measured the temperature dependence of the elastic constants of the 51XX series steels [gear steels] for a range of phases. At RT the normalized steel (pearlite) has the highest value of the moduli, the bainite phase the next highest, and martensite the lowest. Extrapolation of the austenite suggests that at RT austenite has lower moduli than martensite. For all the grades and phases of steels examined, the behavior of the elastic constants is similar: a curve could be drawn for each of… more
Date: September 1, 1997
Creator: Darling, T.; Migliori, A.; Armstrong, P. E.; Vaidya, R.; Scherer, C. & Lowe, T.
Partner: UNT Libraries Government Documents Department
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Influence of carbon partitioning kinetics on final Austenite fraction during quenching and partitioning

Description: The quenching and partitioning (Q&P) process is a two-stage heat-treatment procedure proposed for producing steel microstructures that contain carbon-enriched retained austenite. In Q&P processing, austenite stabilization is accomplished by carbon partitioning from supersaturated martensite. A quench temperature selection methodology was developed to predict an optimum process quench temperature; extension of this methodology to include carbon partitioning kinetics is developed here. Fi… more
Date: January 1, 2009
Creator: Clarke, Amy J; Speer, John G; Matlock, David K; Rizzo, F C; Edmonds, David V & Santofimia, Maria J
Partner: UNT Libraries Government Documents Department
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Nanoscale Twinning and Martensitic Transformation in Shock-Deformed BCC Metals

Description: Shock-induced twinning and martensitic transformation in BCC-based polycrystalline metals (Ta and U-6wt%Nb) have been observed and studied using transmission electron microscopy (TEM). The length-scale of domain thickness for both twin lamella and martensite phase is found to be smaller than 100 nm. While deformation twinning of {l_brace}112{r_brace}<111>-type is found in Ta when shock-deformed at 15 GPa, both twinning and martensitic transformation are found in Ta when shock-deformed at … more
Date: March 22, 2005
Creator: Hsiung, L L
Partner: UNT Libraries Government Documents Department
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A Model of Shape Memory Materials with Hierarchical Twinning: Statics and Dynamics

Description: We consider a model of shape memory material in which hierarchical twinning near the habit plane (austenite-martensite interface) is a new and crucial ingredient. The model includes (1) a triple-well potential ({phi} model) in local shear strain, (2) strain gradient terms up to second order in strain and fourth order in gradient, and (3) all symmetry allowed compositional fluctuation induced strain gradient terms. The last term favors hierarchy which enables communication between macroscopic (c… more
Date: July 1, 1995
Creator: Saxena, A.; Bishop, A. R.; Shenoy, S. R.; Wu, Y. & Lookman, T.
Partner: UNT Libraries Government Documents Department
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Final Report: FG02-01ER-45906 - A novel class of artificially modulated magnetic multilayers based on magnetic shape memory alloys

Description: The temperature dependent micromagnetic behavior, structural phase transitions, magnetic transition, and the dynamics of phase transitions have been investigated using magnetic shape memory alloys. Results provide a novel concept of ‘polymagnets’. In thin film form the number of martensite variants is greatly reduced. A new technique to study dynamics of magnetic phase transitions has been developed applicable to bulk, thin films or multilayers. Transition pathways in magnetic shape memory al… more
Date: June 20, 2005
Creator: Chopra, H. D.
Partner: UNT Libraries Government Documents Department
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Computer simulation of martensitic transformations

Description: The characteristics of martensitic transformations in solids are largely determined by the elastic strain that develops as martensite particles grow and interact. To study the development of microstructure, a finite-element computer simulation model was constructed to mimic the transformation process. The transformation is athermal and simulated at each incremental step by transforming the cell which maximizes the decrease in the free energy. To determine the free energy change, the elastic ene… more
Date: November 1, 1993
Creator: Xu, Ping
Partner: UNT Libraries Government Documents Department
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Burst Martensitic Transformations in a Steel and in a Pu-Ga Alloy

Description: Upon cooling a Pu-2.0 at% Ga alloy from the ambient temperature, the metastable delta phase partially transforms martensitically to the alpha-prime phase. Because this transformation involves a 25% volume contraction, plastic accommodation by the delta matrix must occur. When the material is isochronally heated or isothermally annealed above ambient temperatures, the reversion of alpha-prime to delta is likely to occur by the alpha-prime/delta interface moving to consume the alpha-prime particl… more
Date: June 14, 2005
Creator: Blobaum, K; Krenn, C; Wall, M & Schwartz, A
Partner: UNT Libraries Government Documents Department
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Final report DOE project, ''Origins of asymmetric stress-strain response in phase transformations,'' DEFG02-93ER143993

Description: For the first time, experiments on NiTi under pressure loadings were conducted in Ref. (1). This work showed that the stress-strain response of NiTi is highly pressure sensitive and there was an asymmetry of tension and compression results. The results were obtained based on the special rig developed in (Ref. 2) by Sehitoglu and his students. Several experiments under pressure were also conducted on CuZnAl alloys with also pressure dependent response. accounted for variant-variant interaction a… more
Date: January 30, 2002
Creator: Sehitoglu, Huseyin
Partner: UNT Libraries Government Documents Department
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Local Structure and Vibrational Properties of α'-Pu Martensitein Ga-Stabilized δ-Pu

Description: Extended x-ray absorption fine structure spectroscopy (EXAFS) is used to investigate the local atomic environment and vibrational properties of plutonium and gallium atoms in the {alpha}{prime} and {delta} phases of a mixed phase Pu-Ga alloy. EXAFS results measured at low temperature compare the structure of the mixed phase sample with a single-phase {delta}-Pu sample. EXAFS spectral components attributed to both {alpha}{prime}-Pu and {delta}-Pu were observed in the mixed phase sample. Ga K-edg… more
Date: February 26, 2003
Creator: Nelson, E. J.; Blobaum, K. J. M.; Wall, M. A.; Allen, P. G.; Schwartz, A. J. & Booth, C. H.
Partner: UNT Libraries Government Documents Department
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Investigation of Thermal-Stress-Fatigue Behavior of Stainless Steels. Quarterly Progress Report No. 8

Description: Thermal-stress-fatigue (TSF) testing of 304 and 304-L austenitic stainiess steels was completed. The testing of ferritic steel (ASTM Type A302, Grade B) and of martensitic stainless steel (Type 403) was 50% completed. TSF and conventional strain-cycling fatigue (SCF) were performed on A302B and 403 steels. A new graphical technique was developed which simplifies the work required to obtain plastic strain range, the variable found to be entirely independent in TSF. The method allows greater accu… more
Date: January 1, 1963
Creator: Horton, K.E .
Partner: UNT Libraries Government Documents Department
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Evidence of Transformation Bursts During Thermal Cycling of a Pu-Ga Alloy

Description: The thermodynamics and kinetics of the fcc (delta) to monoclinic (alpha-prime) phase transformation and its reversion in a plutonium-gallium alloy have been studied using differential scanning calorimetry, resistometry, and dilatometry. Under ambient conditions, the delta phase is metastable in a Pu-2.0 at% Ga alloy. Thermal cycling to below the ambient temperature results in a partial transformation to the alpha-prime phase; this transformation is composition-invariant and exhibits martensitic… more
Date: February 9, 2005
Creator: Blobaum, K M; Krenn, C R; Mitchell, J N; Haslam, J J; Wall, M A; Massalski, T B et al.
Partner: UNT Libraries Government Documents Department
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Effect of electron irradiation on the 3C-4H transformation in a Co-Fe alloy

Description: Preliminary results are presented of a study of electron irradiation on the martensitic transformation in a relatively dilute terminal solid solution of Co+5.75 wt% Fe. The experiments demonstrate qualitatively the profound effect that the damage structure produced by electron irradiation can have on these simple martensitic transformations. Further study is being pursued to attempt to quantify the transformation retardation effect.
Date: March 1, 1996
Creator: Allen, C.W. & Mori, H.
Partner: UNT Libraries Government Documents Department
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Pulsed laser surface hardening of ferrous alloys.

Description: A high power pulsed Nd:YAG laser and special optics were used to produce surface hardening on 1045 steel and gray cast iron by varying the process parameters. Unlike CO{sub 2} lasers, where absorptive coatings are required, the higher absorptivity of ferrous alloys at the Nd:YAG laser wavelength eliminates the necessity of applying a coating before processing. Metallurgical analysis of the treated tracks showed that very fine and hard martensitic microstructure (1045 steel) or inhomogeneous mar… more
Date: September 30, 1999
Creator: Xu, Z.; Reed, C. B.; Leong, K. H. & Hunter, B. V.
Partner: UNT Libraries Government Documents Department
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HYDROGEN EFFECTS ON STRAIN-INDUCED MARTENSITE FORMATION IN TYPE 304L STAINLESS STEEL

Description: Unstable austenitic stainless steels undergo a strain-induced martensite transformation. The effect of hydrogen on this transformation is not well understood. Some researchers believe that hydrogen makes the transformation to martensite more difficult because hydrogen is an austenite stabilizer. Others believe that hydrogen has little or no effect at all on the transformation and claim that the transformation is simply a function of strain and temperature. Still other researchers believe that h… more
Date: December 11, 2008
Creator: Morgan, M & Ps Lam, P
Partner: UNT Libraries Government Documents Department
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Transformation plasticity in ductile solids. Annual progress report, June 1, 1993--May 31, 1994

Description: Research has addressed the role of martensitic transformation plasticity in the enhancement of toughness in high-strength austenitic steels, and the enhancement of formability in multiphase low-alloy sheet steels. In the austenitic steels, optimal processing has achieved a significant increase in strength level, in order to investigate the interaction of strain-induced transformation with the microvoid nucleation and shear localization mechanisms operating at ultrahigh strength levels. The degr… more
Date: April 1, 1994
Creator: Olson, G. B.
Partner: UNT Libraries Government Documents Department
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