scholarly journals Microstructure and Fracture Toughness of Nitrided D2 Steels Using Potential-Controlled Nitriding

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 139
Author(s):  
Ki-Hong Kim ◽  
Won-Beom Lee ◽  
Tae-Hwan Kim ◽  
Seok-Won Son
Keyword(s):  
Fracture Toughness ◽  
Electron Backscatter Diffraction ◽  
Surface Hardness ◽  
Compound Layer ◽  
Crack Growth Behavior ◽  
Effective Technique ◽  
Aisi D2 ◽  
Nitriding Potential ◽  
Localized Plastic Deformation ◽  
Backscatter Diffraction

Potential-controlled nitriding is an effective technique for enhancing the life of steel molds and dies by improving their surface hardness and toughness against fatigue damage. In this study, the effect of the nitriding potential on the microstructure and fracture toughness of nitrided AISI D2 steels was investigated. The nitrided layers were characterized by microhardness measurements, optical microscopy, and scanning electron microscopy, and their phases were identified by X-ray and electron backscatter diffraction. As the nitriding potential increased to 2.0 atm−1/2, an increase in the surface hardness and fracture toughness was observed with the growth of the compound layer. However, both the surface hardness and the fracture toughness decreased at the higher nitriding potential of 5.0 atm−1/2 owing to the increased porosity in the compound layers, which mainly consist of the ε (Fe2–3N) phase. Additionally, by observing crack growth behavior, the fracture toughness was analyzed considering the material characteristics of the diffusion and compound layers. The fracture toughness was influenced by the location of the initial Palmqvist cracks due to the localized plastic deformation of the diffusion layer and increased crack length due to the porous compound layer.

scholarly journals Effect of Nitriding Potential KN on the Formation and Growth of a “White Layer” on Iron Aluminide Alloy

2020 ◽  
Author(s):  
Ngoc Minh Le ◽  
Christian Schimpf ◽  
Horst Biermann ◽  
Anke Dalke
Keyword(s):  
Electron Backscatter Diffraction ◽  
White Layer ◽  
Optical Emission ◽  
Compound Layer ◽  
Nitrogen Atmosphere ◽  
Iron Aluminide ◽  
X Ray Diffraction ◽  
Gas Nitriding ◽  
Nitriding Potential ◽  
Backscatter Diffraction

AbstractThis paper investigates the effect of nitriding potential under well-defined gas nitriding conditions on the formation and growth of a compound layer called “white layer” on a FeAl40 (with the composition of 40 at. pct Al) iron aluminide alloy. The nitriding potential was systematically varied in the range of 0.1 to 1.75 bar−1/2 at 590 °C for 5 hour nitriding time with an ammonia-hydrogen-nitrogen atmosphere. Characterization of the microstructure and phases formed within the white layer was performed using optical and scanning electron microscopy, X-ray diffraction (XRD), electron backscatter diffraction (EBSD), and glow discharge optical emission spectroscopy (GDOES). Experimental results indicated that the nitriding potential strongly influences morphology and crystal structure of the white layer. The nitride compound layer consists of the phases γ′-Fe4N, ε-Fe2-3N, and AlN. A mechanism is proposed for the formation and growth of the white layer, depending on the effect of the nitriding potential.

Surface Characterization of a Nitrided Low Alloy Steel

2011 ◽  
Vol 312-315 ◽  
pp. 70-75
Author(s):  
Mourad Keddam ◽  
R. Kouba ◽  
Redoune Chegroune ◽  
B. Bouarour
Keyword(s):  
Alloy Steel ◽  
Surface Characterization ◽  
Surface Hardness ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Iron Nitrides ◽  
Low Alloy Steel ◽  
Nitrogen Concentrations ◽  
Nitriding Potential ◽  
Nitride Layers

The 32CrMoV13 low alloy steel was gas nitrided at 550°C, for three time durations (6.5, 13 and 20 h) and under a variable nitriding potential (1, 2.2 and 6 atm-0.5). The generated nitride layers were characterized by SEM observations, XRD and GDOS analyses as well as microhardness testing. The XRD analysis indicates that the compound layer was composed of and iron nitrides and CrN phase. The surface hardness (inside the compound layer) was found to be dependent on the nitriding potential value, its value increases as rises. It was shown by GDOS analysis that the upper and lower nitrogen concentrations at the (compound layer / diffusion zone) interface are approximatively: 4 and 0.88 wt. % N, respectively.

Microstructural Investigation of Oxynitrocarburized Components Processed at Different Temperatures

2016 ◽  
Vol 879 ◽  
pp. 268-273
Author(s):  
Daniele Caliari ◽  
Giulio Timelli ◽  
Tiziano Salata ◽  
Sergio Maestri ◽  
Giuseppe Cavagnini
Keyword(s):  
Electron Backscatter Diffraction ◽  
Outer Part ◽  
Industrial Process ◽  
Thermochemical Treatment ◽  
Compound Layer ◽  
Microstructural Investigation ◽  
Different Temperatures ◽  
Wear And Corrosion Resistance ◽  
Low Alloyed Steel ◽  
Backscatter Diffraction

Gas nitrocarburizing combined with a post-oxidation treatment is an interesting industrial process developed in order to improve wear and corrosion resistance of low alloyed steel components. In the present work, the microstructure resulting by a thermochemical treatment, which comprises nitriding, nitrocarburizing and post-oxidation stages, applied to an industrial 16MnCr5 component, has been studied. Both the nitriding and nitrocarburizing temperatures were systematically changed in order to study the resulting phases in the compound layer. The depth of the compound layer have been measured by optical microscopy to evaluate the effect due to the variations in the process variables during the nitrocarburizing process. Moreover, the microstructure has been investigated by means of a scanning electron microscope equipped with a electron backscatter diffraction detector in order to assess the amount and the distribution of Fe-N-C phases. A temperature increase from 510 up to 550°C during the nitriding process inside a NH3 atmosphere induces a higher fraction of ε-Fe2-3(C,N) compounds. On the contrary, nitrocarburizing at 600°C instead of 580°C under a gaseous mix of NH3 (50%), CO2 and N2 favors a greater amount of γ'-Fe4(C,N) nitrides. A greater amount of porosity in the outer part of the compound layer favors a thicker oxide film obtainable with the post-oxidation process.

DILLIDUR 450V

Alloy Digest ◽  
2011 ◽  
Vol 60 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Room Temperature ◽  
Surface Hardness ◽  
Heat Treating ◽  
Hot Working ◽  
Resistant Steel ◽  
Bend Strength

Abstract Dillidur 450V is a water hardened wear-resistant steel with surface hardness at room temperature of 420-480 HB. The steel is easy to weld and bend. Hot working is not recommended. This datasheet provides information on composition, physical properties, hardness, tensile properties, and bend strength as well as fracture toughness. It also includes information on wear resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-638. Producer or source: Dillinger Hütte GTS.

NITRODUR 8524

Alloy Digest ◽  
2017 ◽  
Vol 66 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Fatigue Strength ◽  
Tensile Properties ◽  
High Temperatures ◽  
High Surface ◽  
Surface Hardness ◽  
Operating Temperatures

Abstract NITRODUR 8524 (8CrMo16, 1.8524) is one of the Nitrodur family of nitriding steels that are used where high surface hardness and good fatigue strength are required and the material is also subjected to high temperatures. Nitrided surfaces maintain their hardness and strength at operating temperatures of up to approximately 500–550 deg C (932–1022 deg F). This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on surface qualities as well as casting and forming. Filing Code: SA-807. Producer or source: Schmolz + Bickenbach Group.

Cross Section Analysis of Cu Filled TSVs Based on High Throughput Plasma-FIB Milling

2012 ◽  
Author(s):  
Frank Altmann ◽  
Jens Beyersdorfer ◽  
Jan Schischka ◽  
Michael Krause ◽  
German Franz ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
High Throughput ◽  
Cross Sections ◽  
Electron Backscatter Diffraction ◽  
Grain Structure ◽  
Electron Backscatter ◽  
Section Surface ◽  
Backscatter Diffraction ◽  
Section Analysis

Abstract In this paper the new Vion™ Plasma-FIB system, developed by FEI, is evaluated for cross sectioning of Cu filled Through Silicon Via (TSV) interconnects. The aim of the study presented in this paper is to evaluate and optimise different Plasma-FIB (P-FIB) milling strategies in terms of performance and cross section surface quality. The sufficient preservation of microstructures within cross sections is crucial for subsequent Electron Backscatter Diffraction (EBSD) grain structure analyses and a high resolution interface characterisation by TEM.

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