Microstructures and Properties of DP 600 Steel Conventionally Treated and Intercritically Annealed from As-Quenched Martensite

2018 ◽  
Vol 941 ◽  
pp. 413-419
Author(s):  
Dany Michell Andrade Centeno ◽  
Hélio Goldenstein
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Reference Sample ◽  
Tensile Tests ◽  
Single Step ◽  
X Ray Diffraction ◽  
X Ray ◽  
Volume Fractions ◽  
Step Heat Treatment ◽  
Reference Samples

In this work a DP 600 Dual Phase steel, conventionally treated in order to obtain 40 to 60% austenite at the intercritical temperatures, called reference sample, was compared to samples from the same steel, initially fully austenitized and quenched to 100% martensitic structure and subsequently intercritically tempered once (one step) or twice, (two steps) at intercritical temperatures so as to obtain the same volume fractions of austenite as the conventional DP steel. The single step heat treatment is QL, quench and lamellarization; the two step heat treatment is called QLT, quench and lamellarization and tempering. Heat treatments were conducted on a quenching dilatometer. Samples were characterized by optical, SEM-FEG, EBSD imagining and X Ray Diffraction. Mechanical properties were evaluated by microhardness and tensile tests on sub-size specimens. The results show that QL samples present a complex microstructure composed of ferrite (carbide free high temperature tempered martensite) and fresh martensite composed of crystallites of the order of 1 to 5 μm, with volume fractions of ferrite and martensite similar to the reference samples. X-ray diffraction showed the presence of retained austenite in all treatment conditions, larger for the reference samples when compared with the QL; EBSD images show the retained austenite finely dispersed between the martensite laths and within the limits of martensite blocks. The tensile strength of the QL has higher values than reference DP 600 steel for the similar martensite volume, with smaller uniform and total elongations.

scholarly journals External Reference Samples for Residual Stress Analysis by X-Ray Diffraction

2014 ◽  
Vol 996 ◽  
pp. 221-227
Author(s):  
Fabien Lefebvre ◽  
E. Wasniewski ◽  
Manuel François ◽  
J. Cacot ◽  
P. Le-Bec ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Analysis ◽  
Reference Sample ◽  
X Ray Diffraction ◽  
X Ray ◽  
External Reference ◽  
Residual Stress Analysis ◽  
French Association ◽  
Reference Samples ◽  
Good Calibration

The GFAC (French Association for residual stress analysis) has been working for several years on external reference samples in relation with the EN 15305-2009 standard. The purpose of this campaign is to provide an external reference sample to each laboratory involved in the round-robin to allow a good calibration, a good quality control of their X-ray diffraction system and an easiest way to compare results between laboratories. All the procedures to qualify external reference materials will be described in the paper.

Characterization of Silicide Formation of LPCVD-W By Means of Rutherford Backscatrering Spectrometry and X-Ray Diffractometry

1989 ◽  
Vol 168 ◽  
Author(s):  
S.-L. Zhang ◽  
R. Buchta ◽  
M. Östling
Keyword(s):  
Heat Treatment ◽  
Film Thickness ◽  
Reference Sample ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Si Substrates ◽  
History Of ◽  
Compensation Technique ◽  
Sputter Deposited

AbstractTungsten disilicide (WSi2 ) was formed by annealing 185 nm and 750 nm thick LPCVD-W films deposited on <100>-Si substrates. The thickness of the formed WSi2 was observed by Rutherford backscattering measurements (RBS) to increase parabolically with the annealing time. This agrees with the behavior reported in the literature for sputter deposited or evaporated W films. However, a higher stlicide growth rate was found in this work. An activation energy of 2.6 eV/atom was measured, which is smaller than those for sputter deposited or evaporated W films. The crystal structures of the formed WSi2 and the unreacted W films were analyzed using X-ray diffraction (XRD) technique. The thermal history of the samples was found to play an important role for the crystal structure of the unreacted W and formed WSi2. The as-deposited W films became more oriented to the <100> direction with increasing film thickness, while the unreacted W films on top of the formed WSi2, from the samples annealed at temperatures from 700 to 800°C, became more <100> direction dominated with decreasing W film thickness. The preferred orientation of the grown WSi2 films also varied with the silicidation conditions. These observations indicate that the simple method of determining W film thickness by comparing the W diffraction peak heights of the remaining W films after heat treatment to a reference sample will unavoidably introduce large errors. A compensation technique was suggested where both the W and WSi2 diffraction signals were used. A parameter x, a function of reacted W thickness, was introduced to fit the compensation procedure. The conclusion of this study is that attention should be paid to the orientation change of W and WSi2 films during heat treatment if XRD is employed to study the kinetics of WSi2 formation.

Experimental Study for Ultra High Strength Strapping Flat Steel

2014 ◽  
Vol 490-491 ◽  
pp. 181-185
Author(s):  
Feng Li ◽  
Fang Zhou ◽  
Hong Gang Yang ◽  
Jia Shun Lv ◽  
Leng Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Retained Austenite ◽  
High Strength ◽  
Annealing Process ◽  
Continuous Annealing ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flat Steel

Ultra high strength strapping flat steel is used in packaging for papermaking, tobacco, compressed cotton and wool. At present, there is only one company can produce it by Lead bath quenching line. In this paper, the feasibility to produce new ultra high strength strapping flat steel of which tensional strength is 1350 MPa and elongation is 12% by continuous annealing process was investigated. The experiment result of steelmaking, hot rolling, pickling, cold rolling and continues heat treatment showed, the steel could be got using new chemical composition. The microstructure and X-ray diffraction spectrum of the steel showed, the steel was strengthened and toughened by martensite and retained austenite. The effect of continues heat treatment on microstructure and mechanical properties was discussed.

scholarly journals Single-Step Heat Treatment for the Restoration of Mechanical Properties of Cold-Strained Mining Support Steel 31Mn4

2020 ◽  
Vol 66 (12) ◽  
pp. 687-696
Author(s):  
Gorazd Lojen ◽  
Janez Mayer ◽  
Tonica Bončina ◽  
Franc Zupanič
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cold Deformation ◽  
Charpy Impact ◽  
Tensile Tests ◽  
Single Step ◽  
Subcritical Annealing ◽  
Cost Efficient ◽  
Step Heat Treatment ◽  
Carbide Particles

The steel 31Mn4+QT630 is used frequently for mining support arches. The supports are cold strained, first during service, and again by re-rolling prior to reinstallation, which results in strain hardening and a loss of ductility. Consequently, many of the rerolled arch-segments are not suitable for reinstallation because their mechanical properties are inadequate. The objective of this work was to assess the feasibility of restoration of the required mechanical properties by means of a cost-efficient single step heat treatment. Specimens were cold deformed to different degrees in the range 0 % to 45 % to establish the relation between the degree of cold deformation and the hardness. Differently strain hardened specimens were subjected to subcritical annealing at temperatures 450 °C to 700 °C in the duration 0.5 h to 8 h to determine a suitable time-temperature combinations. Microstructures and mechanical properties were investigated of as-received, cold strained and recrystallized specimens. Tests performed were optical microscopy, scanning electron microscopy, tensile tests, hardness measurements and Charpy impact tests. Elongation at break of the as-received material was below the requirements of the applicable standard, and its microstructure contained significant fractions of pre-eutectoid ferrite and pearlite. Upon cold straining, hardness increased by approximately 2 HV per 1 % of strain. After one-hour recrystallization at 600 °C to 620 °C, the microstructure consisted of a ferritic matrix containing evenly dispersed globular carbide particles. The original ductility was restored, while the elongation, yield strength, and hardness were higher than in the as-received condition. These results confirmed that it is feasible to restore the original mechanical properties of heavily strained profiles with an adequate single-step heat treatment. Furthermore, they indicated that it should be possible to recover the required properties of inhomogeneously strained material with the same set of well optimized heat treatment parameters. Consequently, it should be possible to increase the reuse rate and to decrease the costs for new support arches significantly.

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

scholarly journals Laser-Induced Deposition of Plasmonic Ag and Pt Nanoparticles, and Periodic Arrays

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
Daria V. Mamonova ◽  
Anna A. Vasileva ◽  
Yuri V. Petrov ◽  
Denis V. Danilov ◽  
Ilya E. Kolesnikov ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Pt Nanoparticles ◽  
Single Step ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Periodic Arrays ◽  
Potential Applications ◽  
Surface Decoration ◽  
Wide Potential

Surfaces functionalized with metal nanoparticles (NPs) are of great interest due to their wide potential applications in sensing, biomedicine, nanophotonics, etc. However, the precisely controllable decoration with plasmonic nanoparticles requires sophisticated techniques that are often multistep and complex. Here, we present a laser-induced deposition (LID) approach allowing for single-step surface decoration with NPs of controllable composition, morphology, and spatial distribution. The formation of Ag, Pt, and mixed Ag-Pt nanoparticles on a substrate surface was successfully demonstrated as a result of the LID process from commercially available precursors. The deposited nanoparticles were characterized with SEM, TEM, EDX, X-ray diffraction, and UV-VIS absorption spectroscopy, which confirmed the formation of crystalline nanoparticles of Pt (3–5 nm) and Ag (ca. 100 nm) with plasmonic properties. The advantageous features of the LID process allow us to demonstrate the spatially selective deposition of plasmonic NPs in a laser interference pattern, and thereby, the formation of periodic arrays of Ag NPs forming diffraction grating

Phase selection in precursor-derived yttrium aluminum garnet and related Al2O3–Y2O3 compositions

2005 ◽  
Vol 20 (4) ◽  
pp. 1017-1025 ◽  
Author(s):  
Ashutosh S. Gandhi ◽  
Carlos G. Levi
Keyword(s):  
Heat Treatment ◽  
Yttrium Aluminum Garnet ◽  
Lattice Parameter ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
Phase Selection ◽  
X Ray ◽  
Yttrium Aluminum ◽  
Rich Side ◽  
Nitrate Solutions

Al2O3–Y2O3 powders were synthesized in the range of 25–55% Y2O3 by reverse coprecipitation of nitrate solutions. All starting powders were amorphous and formed primary yttrium aluminum garnet (YAG) upon crystallization. X-ray diffraction detected only garnet in compositions of 30–40% Y2O3 after heat treatment at 1250 °C. Compositions of 45–55% Y2O3 established a metastable YAG + Y4Al2O9 microstructure. The YAG phase field was metastably extended away from its stoichiometry, as indicated by a systematic increase in lattice parameter with Y2O3 content. Although some Al2O3 enrichment was achieved, YAG appears to tolerate greater off-stoichiometry on the Y2O3-rich side. Possible defect structures accommodating the solubility extension were examined. Phase selection results indicate that compositional inhomogeneity is not the only reason behind the appearance of hexagonal YAlO3, which is frequently reported during YAG synthesis.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

TEM and X-Ray Examinations of Intermetallic Phases and Carbides Precipitation in an Fe-Ni Superalloy during Prolonged Ageing

2013 ◽  
Vol 212 ◽  
pp. 15-20
Author(s):  
Kazimierz J. Ducki ◽  
Jacek Mendala ◽  
Lilianna Wojtynek
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Intermetallic Phase ◽  
Intermetallic Phases ◽  
Precipitation Process ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Solid Samples ◽  
Structural Investigations ◽  
X Ray

The influence of prolonged ageing on the precipitation process of the secondary phases in an Fe-Ni superalloy of A-286 type has been studied. The samples were subjected to a solution heat treatment at 980°C for 2 h and water quenched, and then aged at temperatures of 715, 750 and 780°C at holding times from 0.5 to 500 h. Structural investigations were conducted using TEM and X-ray diffraction methods. The X-ray phase analyses performed on the isolates were obtained by anodic dissolution of the solid samples. After solution heat treatment the alloy has the structure of twinned austenite with a small amount of undissolved precipitates, such as carbide TiC, carbonitride TiC0.3N0.7, nitride TiN0.3, carbosulfide Ti4C2S2, Laves phase Ni2Si, and boride MoB. The application of ageing causes precipitation processes of γ-Ni3(Al,Ti), G (Ni16Ti6Si7), η (Ni3Ti), β (NiTi) and σ (Cr0.46Mo0.40Si0.14) intermetallic phases, as well as the carbide M23C6. It was found that the main phase precipitating during alloy ageing was the γ intermetallic phase.

scholarly journals Carbonation Resistance of Surface Protective Materials Modified with Hybrid NanoSiO2

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 269
Author(s):  
Kailun Xia ◽  
Yue Gu ◽  
Linhua Jiang ◽  
Mingzhi Guo ◽  
Lei Chen ◽  
...  
Keyword(s):  
Construction Material ◽  
Chemical Components ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Carbonation Depth ◽  
X Ray ◽  
Carbonation Resistance ◽  
Ideal Situation ◽  
Caco3 Content ◽  
Reference Samples

To date, reinforcement concrete is the main construction material worldwide. As the concentration of atmospheric CO2 is steadily increasing, carbonation of the reinforcement concrete becomes a pressing concern. In this study, novel surface protective materials (SPMs) modified with hybrid nanoSiO2 (HNS), fly ash, and slag were developed to reduce CO2 emissions and extend the service life of the reinforcement concrete. The carbonation depths were measured by phenolphthalein to reflect the carbonation resistance. X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA) were conducted to analyze the chemical components of the samples after carbonation. In addition, MIP was carried out to examine the microstructures of the samples prior to carbonation. Thermodynamic modeling was employed to calculate the changes in the phase assemblages of each blends in an ideal situation. The experimental results showed that the carbonation depth and CaCO3 content of the SPM modified with HNS decreased by 79.0% and 64.6% compared with the reference, respectively. The TGA results showed that after carbonation, the CaCO3 contents were 4.40% and 12.42% in the HNS modified samples and reference samples, respectively. MIP analysis demonstrated that the incorporation of HNS in SPM led to a 48.3% and 58.5% decrease in big pores and capillary pores, respectively. Overall, the SPMs modified with HNS in this study possessed better carbonation resistance and refined pore structures.

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