On the α+γ↔γ-Phase Boundary in Nickel and in Manganese Containing Stainless Steel Alloys

2008 ◽  
pp. 704-704-18
Author(s):  
W Schüle
Keyword(s):  
Stainless Steel ◽  
Phase Boundary ◽  
Steel Alloys

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.

scholarly journals Study on Molten Salt Corrosion Behavior of Several Stainless Steel Alloys

2021 ◽  
Vol 1885 (3) ◽  
pp. 032005
Author(s):  
Dandan Men ◽  
Jian Xiong ◽  
Wenyi Peng ◽  
Lingyun Bai
Keyword(s):  
Stainless Steel ◽  
Molten Salt ◽  
Corrosion Behavior ◽  
Steel Alloys ◽  
Salt Corrosion

Development of L12-ordered Ni3(Al,Ti)-strengthened alumina-forming austenitic stainless steel alloys

2013 ◽  
Vol 69 (11-12) ◽  
pp. 816-819 ◽  
Author(s):  
Yukinori Yamamoto ◽  
Govindarajan Muralidharan ◽  
Michael P. Brady
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Steel Alloys

scholarly journals Imaging Hydrogen in Stainless Steel Alloys by Kelvin Probe Force Microscopy

2018 ◽  
Author(s):  
J. D. McNamara ◽  
A. J. Duncan ◽  
M. J. Morgan ◽  
P. S. Korinko
Keyword(s):  
Stainless Steel ◽  
Grain Boundaries ◽  
Contact Potential Difference ◽  
Kelvin Probe Force Microscopy ◽  
Grain Structure ◽  
Kelvin Probe ◽  
Contact Potential ◽  
Steel Alloys ◽  
Force Microscopy ◽  
Net Shaping

Kelvin probe force microscopy (KPFM) was used to image austenitic stainless steel (SS) samples (Type 304L) fabricated by the laser engineered net shaping (LENS®) process. The samples were hydrogen charged (H-charged) and subsequently cut and polished. The surface contact potential difference (CPD) of the samples was measured using the KPFM technique, a form of atomic force microscopy. A set of uncharged samples was also studied for reference and changes in the CPD were on the noise level. For H-charged samples fabricated by the LENS® process, the resulting surface potential images show a change in CPD of about 10 – 20mV around cell-like boundaries (5–10 μm in size) and grain boundaries (50–100 μm in size). The significant change in the CPD is affected by variation of the local work function, which indicates the presence of hydrogen. The elemental composition of the LENS® samples was studied using energy dispersive spectroscopy (EDS) which showed an increase in the atomic percentage of Cr and a decrease in Ni around the cell-like boundaries. The existence of intercellular ferrite on the sub-grain boundaries may explain the propensity of hydrogen to segregate around these regions. The finer grain structure of LENS® samples compared to that of forged or welded samples suggests that the hydrogen can be dispersed differently throughout this material than in traditionally forged austenitic SS. This study is conducted to elucidate the behavior of hydrogen with respect to the microstructure of additively manufactured stainless steel alloys.

scholarly journals Nanotribological behavior of deep cryogenically treated martensitic stainless steel

2017 ◽  
Vol 8 ◽  
pp. 1760-1768 ◽  
Author(s):  
Germán Prieto ◽  
Konstantinos D Bakoglidis ◽  
Walter R Tuckart ◽  
Esteban Broitman
Keyword(s):  
Stainless Steel ◽  
Retained Austenite ◽  
Elastic Limit ◽  
Martensitic Stainless Steel ◽  
Tribological Performance ◽  
Low Carbon ◽  
Displacement Control ◽  
Friction Behavior ◽  
Steel Alloys ◽  
First Time

Cryogenic treatments are increasingly used to improve the wear resistance of various steel alloys by means of transformation of retained austenite, deformation of virgin martensite and carbide refinement. In this work the nanotribological behavior and mechanical properties at the nano-scale of cryogenically and conventionally treated AISI 420 martensitic stainless steel were evaluated. Conventionally treated specimens were subjected to quenching and annealing, while the deep cryogenically treated samples were quenched, soaked in liquid nitrogen for 2 h and annealed. The elastic–plastic parameters of the materials were assessed by nanoindentation tests under displacement control, while the friction behavior and wear rate were evaluated by a nanoscratch testing methodology that it is used for the first time in steels. It was found that cryogenic treatments increased both hardness and elastic limit of a low-carbon martensitic stainless steel, while its tribological performance was enhanced marginally.

Effect of the Flow Velocity on the Corrosion Behavior of UNS S41426 Stainless Steel in the Extremely Aggressive Oilfield Environment for the Tarim Area

CORROSION ◽  
10.5006/2813 ◽  
2020 ◽  
Vol 76 (7) ◽  
pp. 654-665 ◽  
Author(s):  
Yang Zhao ◽  
Limin Chang ◽  
Tao Zhang ◽  
Junfeng Xie ◽  
Yan Chen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Rate ◽  
Phase Boundary ◽  
Flow Velocity ◽  
Passive Film ◽  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Defect Density ◽  
Electrochemical Techniques ◽  
Experimental Results

Effect of flow velocity on the passive film and pitting corrosion behavior of UNS S41426 stainless steel (SS) under the extreme oilfield environment was investigated using different techniques such as microscopy, nanoindentation, and electrochemical techniques. The experimental results show that the corrosion rate of UNS S41426 SS increased with velocity. The increase in flow velocity decreased the thickness and content of amorphous Cr(OH)3 (s) in the film. This in turn increased the density of phase boundary, resulting in a higher defect density. Thus, the UNS S41426 SS film became susceptible to breaking. Furthermore, the pitting had a higher susceptibility to grow to a larger size both in the vertical and horizontal directions with the increase in flow velocity.

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