scholarly journals Microstructure, Mechanical Behavior and Crystallographic Texture in a Hot Forged Dual Phase Stainless Steel.

2021 ◽  
Author(s):  
Riad Badji ◽  
Bellel Cheniti ◽  
Charlie Kahloun ◽  
Thierry Chauveau ◽  
Mohammed Hadji ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Mechanical Behavior ◽  
Grain Boundaries ◽  
Crystallographic Texture ◽  
Hot Forging ◽  
Dislocation Nucleation ◽  
S Phase ◽  
Dual Phase ◽  
Gradual Change ◽  
Temperature Range

Abstract In this work, the hot forging behavior of a dual phase stainless steel in the temperature range of 850 – 1250 °C was investigated. The study revealed the occurrence of a significant cracking phenomenon for processing temperatures below 950 °C that was attributed to the combined effect of intermetallic precipitation and severe deformation. EBSD examination highlighted the occurrence of continuous dynamic recrystallization in both ferrite and austenite microstructures for processing temperatures above 1050 °C. Increasing the hot forging temperature to 1250 °C increased the low angle grain boundaries fraction and lowered the one of the high angle grain boundaries. This was accompanied by a gradual change in the crystallographic texture of the material. The mechanical behavior investigation showed that the steel plasticity, sharply dropped after forging at 850°, was gradually recovered after hot forging at temperatures above 1050°C. This was confirmed by nanoindentation measurements that revealed a remarkable increase of the hardness and young modulus of the steel after hot forging at 850°C and 950°C due to the dislocation nucleation and the s phase precipitation at g/δ interface. The enhancement of dislocation movement at the vicinity of the grain boundaries due to the absence of s phase as well as the dynamic recovery and recrystallization occurring in the temperature range of 1050°C - 1250 °C improved the global mechanical properties of the hot forged steel.

Effect of martensite volume fraction on the mechanical behavior of an UNS S41003 dual-phase stainless steel

2020 ◽  
Vol 797 ◽  
pp. 140208
Author(s):  
Geraldo Lúcio de Faria ◽  
Leonardo Barbosa Godefroid ◽  
Isadora Pereira Nunes ◽  
José Carlos de Lacerda
Keyword(s):  
Stainless Steel ◽  
Mechanical Behavior ◽  
Volume Fraction ◽  
Dual Phase ◽  
Martensite Volume Fraction

Corrosion of Type 310 Stainless Steel By Synthetic Fuel Oil Ash★

CORROSION ◽  
1959 ◽  
Vol 15 (8) ◽  
pp. 61-64 ◽  
Author(s):  
HUGH L. LOGAN
Keyword(s):  
Stainless Steel ◽  
Grain Boundaries ◽  
Fuel Oil ◽  
Synthetic Mixture ◽  
Vanadium Compound ◽  
Synthetic Fuel ◽  
Temperature Range ◽  
310 Stainless Steel

Abstract In an investigation of the corrosion of Type 310 stainless steel in synthetic fuel oil ash, the minimum temperatures at which the steel was attacked by a mixture of V2O5 and Na2SO4 and by mixtures of V2O5 and NaVO3 were determined. The minimum temperatures ranged from 1075 F for a mixture of 67 percent V2O5 and 33 percent NaVO3 to 1220 F for a mixture of 88.5 percent V2O5 and 11.5 percent NaVO3. An unidentified phase was produced at the interface between the steel and a vanadium compound or mixtures of compounds in the temperature range 1075 F to 1890 F. There was evidence that this phase penetrated into the steel at grain boundaries. Steel heated above 1700 F in contact with a vanadium compound or a mixture of these contained nodules of an unidentified phase at the grain boundaries. Spectrochemical analyses of the slag (fused synthetic mixture) indicated that it contained some of the components of the steel in the same proportions as they were present in the steel. 4.3.3

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.

Precipitation kinetics and mechanical behavior in a solution treated and aged dual phase stainless steel

2014 ◽  
Vol 148 (3) ◽  
pp. 664-672 ◽  
Author(s):  
R. Badji ◽  
N. Kherrouba ◽  
B. Mehdi ◽  
B. Cheniti ◽  
M. Bouabdallah ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Mechanical Behavior ◽  
Dual Phase ◽  
Precipitation Kinetics ◽  
Solution Treated

Temper Embrittlement and Corrosion Behaviour of Martensitic Stainless Steel 420

2013 ◽  
Vol 794 ◽  
pp. 757-765 ◽  
Author(s):  
K. Chandra ◽  
Vivekanand Kain ◽  
N. Srinivasan ◽  
I. Samajdar ◽  
A. K. Balasubrahmanian
Keyword(s):  
Stainless Steel ◽  
Grain Boundaries ◽  
Martensitic Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Corrosion Behaviour ◽  
Temper Embrittlement ◽  
Electron Microscopic Examination ◽  
Intergranular Cracking ◽  
Electron Microscopic ◽  
Temperature Range

Tempering of alloy steels in the temperature range of 400-600 °C causes temper embrittlement i.e. decrease in notch toughness of the material and the nil ductility temperature is raised to room temperature and above. The fracture in temper-embrittled steel is intergranular and propagates along prior austenitic grain boundaries. The embrittlement occurs only in the presence of specific impurities, e.g. P, Sn, Sb and As. These elements have been shown to segregate along prior austenite grain boundaries during tempering. Similar type of temper embrittlement can occur in martensitic stainless steel (SS) if tempered in the temperature range of 450-600 °C. This paper reports a case of failure of components made from martensitic SS 420 due to temper embrittlement. These components were subjected to a temperature of 120 °C in the initial stages of service and had shown brittle fractures. Scanning electron microscopic examination of the fracture surface of both the components showed intergranular fracture. The microstructures of the failed components confirmed that the materials were in hardened and tempered condition. In addition, the microstructure revealed both intergranular corrosion (IGC) and intergranular cracking. The electron backscatter diffraction study also showed retained austenite in the first components material. The material undergoing IGC might be related to a wrong heat-treatment during fabrication and subsequent pickling procedures. To confirm this, a sample each from both the components was exposed to 5% nitric acid solution at 25 °C. The results showed very high corrosion rate and the attack was intergranular in nature. The failure of both the components was concluded to be due to wrong tempering treatment in the temperature range of 450-600 °C that cause grain boundaries to become susceptible to embrittlement and corrosion.

Domain coarsening by grain boundary migration in ordered Ni4Mo

1986 ◽  
Vol 44 ◽  
pp. 560-561
Author(s):  
K. Vasudevan ◽  
H. P. Kao ◽  
C. R. Brooks ◽  
E. E. Stansbury
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Short Range ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Rapid Cooling ◽  
Temperature Range ◽  
Fee Structure ◽  
Domain Coarsening ◽  
Boundary Reaction

The Ni4Mo alloy has a short-range ordered fee structure (α) above 868°C, but transforms below this temperature to an ordered bet structure (β) by rearrangement of atoms on the fee lattice. The disordered α, retained by rapid cooling, can be ordered by appropriate aging below 868°C. Initially, very fine β domains in six different but crystallographically related variants form and grow in size on further aging. However, in the temperature range 600-775°C, a coarsening reaction begins at the former α grain boundaries and the alloy also coarsens by this mechanism. The purpose of this paper is to report on TEM observations showing the characteristics of this grain boundary reaction.

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