scholarly journals Novel Mechanical Characterization of Austenite and Ferrite Phases within Duplex Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1352
Author(s):  
Hossein Besharatloo ◽  
Marcel Carpio ◽  
José-María Cabrera ◽  
Antonio Manuel Mateo ◽  
Gemma Fargas ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
High Speed ◽  
Mapping Technique ◽  
Small Scale ◽  
Processing Conditions ◽  
Excellent Correlation ◽  
Electron Backscattered Diffraction ◽  
Interphase Boundaries

The microstructure and micromechanical properties of the constitutive phases of a particular duplex stainless steel in various processing conditions have been characterized. Hardness (H), elastic modulus (E) and H/E cartography maps were obtained by using a high-speed nanoindentation mapping technique. Small-scale H and E evolution at different processing conditions has been investigated by statistical analysis of a large number of nanoindentations (10,000 imprints per sample). Two mechanically distinct phases, ferrite (α) and austenite (γ), were deconvoluted from this dataset using Ulm and Constantinides’ method, with the remaining values assigned to a third mechanical phase linked to composite-like (containing α/γ interphase boundaries) regions. These mechanical property phase assessments were supplemented by overlaying crystallographic phase maps obtained by electron backscattered diffraction. An excellent correlation between microstructure and small-scale mechanical properties was achieved, especially when considering the ratio H/E.

METALLURGICAL AND CORROSION CHARACTERIZATION OF POST WELD HEAT TREATED DUPLEX STAINLESS STEEL (UNS S31803) JOINTS BY FRICTION WELDING PROCESS

2016 ◽  
Vol 23 (03) ◽  
pp. 1650013 ◽  
Author(s):  
MOHAMMED ASIF M. ◽  
KULKARNI ANUP SHRIKRISHNA ◽  
P. SATHIYA
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Friction Welding ◽  
Volume Fraction ◽  
Welding Process ◽  
Equilibrium Temperature ◽  
Weld Interface ◽  
Heat Treated ◽  
Weld Heat

The present study focuses on the metallurgical and corrosion characterization of post weld heat treated duplex stainless steel joints. After friction welding, it was confirmed that there is an increase in ferrite content at weld interface due to dynamic recrystallization. This caused the weldments prone to pitting corrosion attack. Hence the post weld heat treatments were performed at three temperatures 1080[Formula: see text]C, 1150[Formula: see text]C and 1200[Formula: see text]C with 15[Formula: see text]min of aging time. This was followed by water and oil quenching. The volume fraction of ferrite to austenite ratio was balanced and highest pit nucleation resistance were achieved after PWHT at 1080[Formula: see text]C followed by water quench and at 1150[Formula: see text]C followed by oil quench. This had happened exactly at parameter set containing heating pressure (HP):40 heating time (HT):4 upsetting pressure (UP):80 upsetting time (UP):2 (experiment no. 5). Dual phase presence and absence of precipitates were conformed through TEM which follow Kurdjumov–Sachs relationship. PREN of ferrite was decreasing with increase in temperature and that of austenite increased. The equilibrium temperature for water quenching was around 1100[Formula: see text]C and that for oil quenching was around 1140[Formula: see text]C. The pit depths were found to be in the range of 100[Formula: see text]nm and width of 1.5–2[Formula: see text][Formula: see text]m.

Tribological Characterization of Machining at Very Small Contact Areas

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Michael R. Lovell ◽  
P. Cohen ◽  
Pradeep L. Menezes ◽  
R. Shankar
Keyword(s):  
High Speed ◽  
Friction Mechanisms ◽  
High Speed Steel ◽  
Small Scale ◽  
Machining Processes ◽  
Macroscopic Theory ◽  
Contact Areas ◽  
Tribological Characterization ◽  
Physical Phenomena

When machining miniaturized components, the contact conditions between the tool and the workpiece exhibit very small contact areas that are on the order of 10−5 mm2. Under these conditions, extremely high contact stresses are generated, and it is not clear whether macroscopic theories for the chip formation, cutting forces, and friction mechanisms are applicable. For this reason, the present investigation has focused on creating a basic understanding of the frictional behavior in very small scale machining processes so that evaluations of standard macroscale models could be performed. Specialized machining experiments were conducted on 70/30 brass materials using high-speed steel tools over a range of speeds, feeds, depths of cut, and tool rake angles. At each operating condition studied, the friction coefficient and the shear factor τk were obtained. Based on the experimental results, it was determined that the standard macroscopic theory for analyzing detailed friction mechanisms was insufficient in very small scale machining processes. An approach that utilized the shear factor, in contrast, was found to be better for decoupling the physical phenomena involved. Utilizing the shear factor as an analysis parameter, the parameters that significantly influence the friction in microscale machining processes were ascertained and discussed.

scholarly journals Characterization of Impact Deformation Behavior of a Thermally Aged Duplex Stainless Steel by EBSD

2018 ◽  
Vol 31 (8) ◽  
pp. 798-806 ◽  
Author(s):  
Gang Liu ◽  
Shi-Lei Li ◽  
Hai-Long Zhang ◽  
Xi-Tao Wang ◽  
Yan-Li Wang
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Deformation Behavior ◽  
Impact Deformation

Metallurgical and mechanical characterization of electron beam welded super-duplex stainless steel UNS 32750

2014 ◽  
Vol 16 (4) ◽  
pp. 527-534 ◽  
Author(s):  
K. Devendranath Ramkumar ◽  
Debidutta Mishra ◽  
M.K. Vignesh ◽  
B. Ganesh Raj ◽  
N. Arivazhagan ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Electron Beam ◽  
Duplex Stainless Steel ◽  
Mechanical Characterization ◽  
Super Duplex Stainless Steel
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