overview of intermetallic sigma

1. Motivation - Hindawi

The minimum deviation angle for the sigma phase formation decreases with increasing annealing time. Furthermore, the formation of the phase is strongly affected by the coherency and interfacial energy of the / interface.


Apr 22, 2020 · ASTM A Testing:An Overview of Intergranular Corrosion Element. The Huey test works well to analyze chromium depleted regions and intermetallic precipitates, such as sigma phase, and is also used for materials in strongly oxidizing environments such as nitric acid. ASTM A262 PRACTICE A PDF - PDF Index GabonJan 30, 2021 · ASTM A Testing:An Overview of Intergranular Corrosion Element. For example, in highly oxidizing solutions, intergranular attack can occur due to intermetallic phases, while attack of carbides may occur somewhat less oxidizing solutions. See


Aug 03, 2019 · ASTM A262 PRACTICE E PDF. Abstract. A detailed study of AISI and stainless steels (SSs) has been conducted to correlate the degree of sensitization (DOS) measured by the. ASTM a Test, Intergranular Corrosion, IGC, ASTM A Practice, Copper Copper Sulfate 16% sulfuric acid, ASTM A Practice E (Strauss Test). ASTM A Practice E test. ASTM A262-13 PDFIntergranular corrosion occurs as a result of precipitation of nitridescarbidesand other intermetallic phasessuch as sigma phase, that occurs along the grain boundaries. Please specify the maximum allowable corrosion rate and any available data on the sensitizing heat treatment asttm. This abstract is a brief summary of the referenced standard.

Asm Handbook Volume 9 Metallography And

Overview of Intermetallic Sigma ( ) Phase Precipitation Shinohara et al. [] pointed out that the precipitation of the phase was a diffusion-controlled phase transformation in 25% Cr-20% Ni stainless steel, and that the Cr atom had an important effect on the acceleration of the Effect of Processing Parameters on Intermetallic Phase Effect of Processing Parameters on Intermetallic Phase Content and Impact Toughness for Super Duplex Alloy PM HIP Sandvik SAF 2507 Martin Östlund, Linn Larsson, Tomas Berglund Abstract. PM HIP is a widely applied manufacturing technology to produce thick walled and complex shaped duplex and super duplex stainless steel (DSS and SDSS) components for the petrochemical []

Effects of Electropulsing on the Microstructure Evolution

Thermal crack initiation and pitting corrosion are frequently caused by the formation of the secondary phases such as sigma phase, delta-ferrite phase, carbides and secondary austenite phase in steel. Traditionally, heat treatment is used to minimize these detrimental effects of the secondary phases. In this study, we have applied pulse to the 316L stainless steel and observed the considerable IMPROVED CORROSION PERFORMANCE IN SUPER intermetallic phases and thus the more challenges in the fabrication process. INTERMETALLIC PHASES MORE LIKELY IN ALLOYS Due to the higher alloy content in super duplexes such as UNS S32760 and UNS S32750, they are more prone to the precipitation of intermetallic phases like the sigma phase, chi phase and R phase than a duplex like UNS S31803.

Identification of sigma and chi phases in duplex stainless

Feb 01, 2016 · Sigma phase is a non-magnetic intermetallic based in the system of iron and chromium. It has a tetragonal crystallographic structure with 32 atoms per unit cell [6] that increases the hardness and decreases the toughness, as well as the elongation of the steel [7] , and even changes the fracture type from transgranular to intergranular as the quantity of -phase increases [8] . Investigation on Ti6Al4V-V-Cr-Fe-SS316 Multi-layers Aug 11, 2017 · Literature from previous studies 22,23,24, has reported a brittle intermetallic sigma phase that is always observed in various series of Duplex stainless steels.The sigma

Materials Free Full-Text Effect of Sigma Phase

Sigma phase was the major intermetallic precipitating between 630 °C and 1010 °C and its morphology changed from blocky to fine coral-shaped with decreasing aging temperature. At the same time, the average thickness of the precipitates decreased from 2.9 µm to 0.5 µm. Nickel-base sigma-gamma in-situ intermetallic matrix What is claimed is:1. A nickel-base gamma-sigma intermetallic matrix composite material comprising, in weight percent, about 20 to 50 chromium, about 0 to 32 molybdenum, about 0.5 to 7 silicon, about 0 to 7 aluminum, and about 0 to 3 titanium, with the balance being nickel and incidental impurities, characterized by a sigma volume fraction of greater than 30 percent.

Sigma Phase Characterization in AISI 316 Stainless Steel

Aug 01, 2005 · Overview of Intermetallic Sigma Phase Precipitation in Stainless Steels. ISRN Metallurgy, Vol. 2012, Issue. , p. 1. CrossRef; Google Scholar; Kim, Bum-joon 2013. Small punch creep behavior and nondestructive evaluation of long term aged AISI 316L stainless steel. International Journal of Precision Engineering and Manufacturing, Vol. 14, Issue Study of the Precipitation of Secondary Phases in Duplex Abstract:The aim of this work is to study the precipitation mechanism of the intermetallic phases present in duplex stainless steels (UNS S32205 and UNS S32750), as well as to find out the most suitable method for detecting and analyzing accurately these secondary phases, particularly Sigma-phase, Chi-phase, nitrides and carbides.


Laves phase, sigma phase, M 23 C6 carbides and needle-like titanium-rich carbides (with niobium in solid solution) were observed in the welds and heat-affected zones of gas tungsten arc welds. The presence of intermetallic compounds and carbides embrittled the weld metal and increased the hardness of the weld metal significantly. The fusion Ti-Fe intermetallics analysis and control in joining Apr 01, 2017 · Sigma phase exhibits a tetragonal structure (Chan and Tjong, 2014). Sigma phase is a brittle phase and can decrease the toughness of the system (Sieurin and Sandström, 2007). Sigma phase forms in the cooling process from high temperatures, e.g., in welding (Chan and Tjong, 2014). Sigma phase has the reverse effect on Cr-rich duplex steel (25% Cr).

Utilization of brittle phase for strengthening and

Overview; Fingerprint; Abstract. General design concept used in high-entropy alloys (HEAs) have deviated from forming an fcc single phase to utilizing hard intermetallic phases in ductile fcc matrix. Here, we effectively exploited strengthening effects of a brittle intermetallic sigma () phase to improve cryogenic tensile properties of a non Figure 4 from Overview of Intermetallic Sigma () Phase DOI:10.5402/2012/732471 Corpus ID:72147144. Overview of Intermetallic Sigma Phase Precipitation in Stainless Steels @article{Hsieh2012OverviewOI, title={Overview of Intermetallic Sigma Phase Precipitation in Stainless Steels}, author={Chih-Chun Hsieh and Weite Wu}, journal={International Scholarly Research Notices}, year={2012}, volume={2012}, pages={1-16} }

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