scholarly journals Composition equivalents of stainless steels understood via gamma stabilizing efficiency

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuqi Zhang ◽  
Qing Wang ◽  
Rui Yang ◽  
Chuang Dong
Keyword(s):  
Stainless Steel ◽  
Phase Boundary ◽  
Stainless Steels ◽  
Alloying Elements ◽  
Positive Sign ◽  
Equivalent Scheme ◽  
Α Phase ◽  
Phase Type ◽  
Boundary Lines

AbstractThe phase-type of a stainless steel is generally predicted by equivalent equations in terms of a major austenitic (γ) or ferritic (α) stabilizer Ni or Cr. The present paper attempts to understand the equivalent methods in stainless steels via the slopes of the phase boundary lines separating γ and γ + α phase zones. The prevailing equivalent coefficients are well interpreted using the slope ratios of the alloying elements divided by that of Ni or Cr, after analyzing over one hundred common stainless steels. Different from traditional composition equivalents which evaluate γ stabilizers and α stabilizers separately; the new equivalent scheme provides a unified phase stabilizing parameter for all alloying elements in stainless steels. This parameter is defined as γ stabilizing efficiency. Its negative or positive sign indicates γ stabilizer or α stabilizer, and its value represents the stabilizing efficiency.

Examination of the Orientation Relationships between the Main Phases of Duplex Stainless Steel by EBSD

2007 ◽  
Vol 537-538 ◽  
pp. 297-302
Author(s):  
Tibor Berecz ◽  
Péter János Szabó
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Stainless Steels ◽  
Electron Backscatter Diffraction ◽  
Duplex Stainless Steels ◽  
Alloying Elements ◽  
Orientation Relationships ◽  
Σ Phase ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Duplex stainless steels are a famous group of the stainless steels. Duplex stainless steels consist of mainly austenitic and ferritic phases, which is resulted by high content of different alloying elements and low content of carbon. These alloying elements can effect a number of precipitations at high temperatures. The most important phase of these precipitation is the σ-phase, what cause rigidity and reduced resistance aganist the corrosion. Several orientation relationships have been determined between the austenitic, ferritic and σ-phase in duplex stainless steels. In this paper we tried to verify them by EBSD (electron backscatter diffraction).

scholarly journals A CLOSER EXAMINATION OF THE CLAIMS OF EXCELLENT CORROSION RESISTANCE OF STAINLESS STEEL: TEXTBOOK MISCONCEPTIONS AND MISINTERPRETATIONS

2015 ◽  
Author(s):  
Aezeden O. Mohamed
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Stainless Steels ◽  
Alloying Elements ◽  
Excellent Corrosion Resistance ◽  
The Common ◽  
Engineering Materials

This paper examines misconceptions and misinterpretations concerning the common assertion in textbooks that stainless steels has excellent corrosion resistance due to the addition of alloying elements such as nickel (Ni), chromium (Cr), and molybdenum (Mo).A closer look at this claim reveals underlying assumptions that lead to this imprecise statement. Corrosion experiments have been established in a course in engineering materials that expose these assumptions.Following a discussion of the tests and their results, it is suggested that statements in textbooks that stainless steel has excellent corrosion resistance should be qualified. It is hoped that by bringing this shortcoming to the attention of engineering educators, the misconceptions and misinterpretations can be corrected.

Precipitation at α/γ interfaces in duplex stainless steel

1992 ◽  
Vol 50 (1) ◽  
pp. 60-61
Author(s):  
M.G. Burke ◽  
E.A. Kenik
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Grain Boundaries ◽  
Duplex Stainless Steel ◽  
Stainless Steels ◽  
Analytical Electron Microscopy ◽  
Nuclear Industry ◽  
Temperature Range ◽  
Α Phase ◽  
Analytical Electron

Duplex (austenite/ferrite) stainless steels are used in a variety of applications in the nuclear industry, particularly for coolant pipes, valves and pumps. These materials may become embrittled after prolonged ageing in the temperature range ∼350 - 550°C due to precipitation of G-phase, an FCC-based Ni silicide, and the formation of a Cr-rich α' phase in the ferrite. In addition to the intragranular G-phase precipitates, preferential precipitation of other phases is often observed at grain boundaries, particularly α/γ interfaces. In this examination, the precipitates formed in a Nb-containing duplex stainless steel have been identified using analytical electron microscopy.

Role of Alloying Elements on the Cytotoxic Behavior and Corrosion of Austenitic Stainless Steels

2005 ◽  
Vol 475-479 ◽  
pp. 2295-2298 ◽  
Author(s):  
Young Sik Kim ◽  
Y.R. Yoo ◽  
C.G. Sohn ◽  
Keun Taek Oh ◽  
Kyoung Nam Kim ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Current Density ◽  
Stainless Steels ◽  
Alloying Elements ◽  
Passive Current Density ◽  
Ti Alloys ◽  
Metal Ion Release ◽  
Passive Current ◽  
Super Austenitic Stainless Steel

Super stainless steel has been used to solve corrosion problems of biomaterials because it shows the excellent corrosion resistance as like Ti and Ti alloys and has better mechanical properties than Ti and Ti alloys. We designed high Mo and Ni bearing super austenitic stainless steel. To obtain desirable microstructure, Cr, Ni, Mo, N contents were controlled. This work focused on the role of alloying elements on cytotoxic behavior and corrosion of stainless steel. In acidic chloride solution, when the alloys had high PRE values, the alloys showed high pitting resistance and low critical current density. However, in Hanks’ solution, the higher PRE’s alloys showed high critical passive current density. Namely, it was revealed that EDTA among Hanks’ solution played an important role to increase the critical passive current density of high Mo and Ni bearing super stainless steels, regardless of PRE’s value of the alloys. Therefore, even if the PRE values of the alloys were higher, high Ni and Mo bearing alloys would reveal more cytotoxic and high metal ion release rate than 316L stainless steel.

scholarly journals A study of bacteria adhesion and microbial corrosion on different stainless steels in environment containing Desulfovibrio vulgaris

2021 ◽  
Vol 8 (1) ◽  
pp. 201577
Author(s):  
T. T. T. Tran ◽  
K. Kannoorpatti ◽  
A. Padovan ◽  
S. Thennadil
Keyword(s):  
Stainless Steel ◽  
Surface Properties ◽  
Passive Film ◽  
Stainless Steels ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Bacterial Attachment ◽  
Alloying Elements ◽  
Desulfovibrio Vulgaris ◽  
Microbial Corrosion

Stainless steel is an important material used in many applications due to its mechanical strength and corrosion-resistant properties. The high corrosion resistance of stainless steel is provided by the passive film. Different stainless steels have different alloy elements and surface properties which could have a significant influence on bacterial attachment to the surface and thus might result in different microbial corrosion behaviours. In this study, the effect of adhesion of sulfate-reducing bacteria (SRB) on corrosion behaviour in artificial seawater on different stainless steels was investigated. Stainless steel materials used were SS 410, SS 420, SS 316 and DSS 2205 and pure chromium. The contact angle was measured to study the effect of surface properties of materials. Adhesion was measured by counting cells attached to the surface of materials. The corrosion behaviour of the materials was measured by electrochemical testing including measuring open circuit potential, electrochemical impedance spectroscopy and potentiodynamic behaviour. The long-term corrosion behaviour of each material was studied after six months of exposure by measuring weight loss and surface analysis with scanning electron microscope with energy-dispersive X-ray analysis. Hydrophobicity had a strong effect on bacterial attachment. Alloying elements e.g. nickel also had shown its ability to attract bacteria to adhere on the surface. However, the corrosion rate of different materials is determined not only by bacterial attachment but also by the stability of the passive film which is determined by the alloying elements, such as Mo and Cr. Chromium showed high resistance to corrosion, possibly due to toxicity on bacterial attachment. The nature of bacterial attachment and corrosion behaviour of the materials are discussed.

Regularities of the Influence of Substitutional and Interstitial Alloying Elements on the Corrosion Properties of Austenitic Stainless Steels

2021 ◽  
Vol 410 ◽  
pp. 336-341
Author(s):  
Eugeny A. Merkushkin ◽  
Vera V. Berezovskaya ◽  
Mikhail A. Serzhanin
Keyword(s):  
Stainless Steel ◽  
Nitrogen Content ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Total Content ◽  
Alloying Elements ◽  
Corrosion Properties ◽  
Positive Role ◽  
Pitting Potential ◽  
Corrosion Studies

Pitting corrosion studies were carried out on nitrogen containing austenitic stainless steels of different compositions and concentrations of alloying elements. As was shown there is a certain predicted influence of the concentration of each alloying elements as chromium, manganese, nickel, carbon and nitrogen on the pitting potential (Eb) of investigated steels with the nitrogen content less than 0.169 wt. %. However with an increase of the nitrogen content to a certain value (in our study up to 0.82 wt. %) the predicting of alloying elements influence on pitting potential of the steels requires a new approach. Based on the analysis of the experimental results and to take into account the influence of all alloying elements in steel on the pitting potential, a regression equation is proposed. In the presence of nitrogen, the positive role of carbon on the pitting resistance of stainless steel was shown, and the critical values of the total content (C + N) and the C / N ratio were determined, allowing prediction of the best composition of stainless steel.

NiAl precipitation in Fe-12w/o Cr-5w/o Ni-4w/o Al

1983 ◽  
Vol 41 ◽  
pp. 202-203
Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar
Keyword(s):  
Solid Solution ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Alloy Composition ◽  
Chromium Content ◽  
Scale Up ◽  
Optical Metallography ◽  
Property Evaluation ◽  
310 Stainless Steel ◽  
Microstructural Studies

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.

BRILLIANT 2101 T-1 AP

Alloy Digest ◽  
2012 ◽  
Vol 61 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Tensile Properties ◽  
Stainless Steels ◽  
Duplex Stainless Steels ◽  
Good Balance ◽  
Steel Wires

Abstract Stoody AP stainless steel wires are all-position wires. The nickel in this product will achieve a good balance of austenite and ferrite in lean duplex stainless steels. This datasheet provides information on composition and tensile properties as well as fracture toughness. It also includes information on forming and joining. Filing Code: SS-1118. Producer or source: Stoody Company.

AISI No. 633

Alloy Digest ◽  
1981 ◽  
Vol 30 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Stainless Steels ◽  
High Strength ◽  
Heat Treating ◽  
Corrosion Resistant ◽  
Martensitic Stainless Steels ◽  
Steel Mills ◽  
Temperature Performance ◽  
Structural Applications

Abstract AISI No. 633 is a chromium-nickel-molybdenum stainless steel whose properties can be changed by heat treatment. It bridges the gap between the austenitic and martensitic stainless steels; that is, it has some of the properties of each. Its uses include high-strength structural applications, corrosion-resistant springs and knife blades. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-389. Producer or source: Stainless steel mills.

AISI TYPE 303 and 303Se

Alloy Digest ◽  
1961 ◽  
Vol 10 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Stainless Steels ◽  
Heat Treating ◽  
Steel Mills ◽  
Temperature Performance ◽  
Aisi Type

Abstract AISI Types 303 and 303 Se austenitic chromium nickel stainless steels to which elements have been added to improve machining and non-seizing characteristics. They are the most readily machinable of all the austenitic chromium nickel grades and are suitable for use in automatic screw machines. They are widely used to minimize seizing and galling. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-126. Producer or source: Stainless steel mills.

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