scholarly journals Precipitation Hardening on Mechanical and Corrosion Properties of Extruded Mg10Gd Modified with Nd and La

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 640 ◽  
Author(s):  
Petra Maier ◽  
Maximilian Bechly ◽  
Chamini Mendis ◽  
Norbert Hort
Keyword(s):  
Grain Size ◽  
Precipitation Hardening ◽  
Volume Fraction ◽  
Alloying Elements ◽  
Corrosion Properties ◽  
Grain Boundary Mobility ◽  
Initiation And Propagation ◽  
Improve Fracture Toughness ◽  
Mechanical And Corrosion Properties ◽  
Low Solubility

To improve the mechanical and corrosion properties of Mg10Gd, Nd and La are added, and from that, the influence of precipitation hardening was studied. An increase in strength, by decreasing grain size and increasing the volume fraction of Rare Earth-rich precipitates, has been found when increasing the amount of alloying elements. Alloys containing La appear less ductile. Where crack propagation is studied using 3-point bending on Mg10Gd and Mg10Gd1Nd, the failure is mostly driven by twinning; the alloys with La show suppressed twinning, but crack initiation and propagation is caused by brittle and coarse precipitates. Precipitation hardening did not improve fracture toughness and was mostly based on strong grain growth and low solubility of La in Mg. With added alloying elements, the grain size was found to be slightly smaller in the T6 condition—precipitates seem to pin grain boundaries and therefore limit grain boundary mobility. Alloys containing Nd showed the best precipitation hardening response. Corrosion behavior, investigated by voltammetry and immersion, showed the best behavior in the precipitation-hardened condition. Corrosion rates and surface morphology are used to discuss corrosion properties.

Microstructural Control of Ductile Crack Propagation in TMCP HSLA Pipeline Steels

2014 ◽  
Vol 922 ◽  
pp. 568-573
Author(s):  
Victor Carretero Olalla ◽  
N. Sanchez Mouriño ◽  
Philippe Thibaux ◽  
Leo Kestens ◽  
Roumen H. Petrov
Keyword(s):  
Grain Size ◽  
Crack Propagation ◽  
Volume Fraction ◽  
Main Role ◽  
Charpy Test ◽  
Initiation And Propagation ◽  
Average Grain Size ◽  
Main Disadvantage ◽  
Steel Grades ◽  
Increasing Demand

Control of ductile fracture propagation is one of the major concerns for pipeline industry, particularly with the increasing demand of new control rolled steel grades required to maintain integrity at high operational pressures. The objective of this research is to understand which microstructural features govern crack propagation, and to analyse the effect of two of them (average grain size, and volume fraction of pearlite). The main disadvantage during classical Charpy test was to discriminate the crack initiation and propagation energy during fracture of a notched sample. The initiation appears to be caused by the stress state in the neighbouring of Ti-containing precipitates or pearlite particles (no presence of M/A constituents or MnS inclusions was detected in the evaluated grades), propagation-arrest of the crack is assumed to play the main role concerning the control of fracture. Our approach to characterize the fracture resistance is to measure the energy absorbed during the crack propagation stage by means of load-displacement curves obtained via instrumented Charpy test. It was observed that the energy absorbed during crack propagation is not influenced by the average grain size but by the fraction and the morphological (banded-not banded) distribution of second pearlitic phase. This suggests that a different approach to characterize the heterogeneities in grain size clustering might be followed to correlate the energy measured during crack propagation and the morphological features of the steel.

Influence of Thermal Aging on the Mechanical and Corrosion Properties of GTAW Welds of Alloy N06022

2002 ◽  
Vol 713 ◽  
Author(s):  
Tammy S. Edgecumbe Summers ◽  
Raúl B. Rebak ◽  
Todd A. Palmer ◽  
Paul Crook
Keyword(s):  
Volume Fraction ◽  
Charpy Impact ◽  
Corrosion Properties ◽  
Charpy Impact Toughness ◽  
Gas Tungsten Arc ◽  
Hydrochloric Acid Solutions ◽  
Tcp Phase ◽  
Mechanical And Corrosion Properties ◽  
Gas Tungsten Arc Welds ◽  
Kinetics Of

ABSTRACTThe phase stability of C-22 alloy (UNS N06022) gas tungsten arc welds was studied by aging samples at 593, 649, 704, and 760°C for times up to 6,000 hours. The tensile properties and the Charpy impact toughness of these samples were measured in the as-welded condition as well as after aging. The corrosion resistance was measured using standard immersion tests in acidic ferric sulfate (ASTM G 28 A) and 2.5% hydrochloric acid solutions at the boiling point. The microstructures of weld samples were examined using scanning electron microscopy (SEM). Precipitate volume fraction measurements were made using optical microscopy.Degradation of the mechanical and corrosion properties of C-22 welds due to aging at all temperatures investigated was seen to occur sooner than was seen in C-22 base metal. An evaluation of the kinetics of nucleation and growth of the precipitates forming at these temperatures, however, indicated that no significant changes in TCP phase morphology would occur at temperatures below approximately 300°C.a

AZ31 and WE43 Alloys for Biomedical Applications

2017 ◽  
Vol 270 ◽  
pp. 205-211 ◽  
Author(s):  
Drahomír Dvorský ◽  
Jiří Kubásek ◽  
Dalibor Vojtěch
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Biomedical Applications ◽  
Intermetallic Phases ◽  
Alloying Elements ◽  
Biodegradable Implants ◽  
Preparation Process ◽  
Magnesium Matrix ◽  
Corrosion Properties ◽  
Mechanical And Corrosion Properties

Magnesium and its alloys are considered for application as materials for biodegradable implants as they have mechanical properties similar to bone tissue. High demands on corrosion and mechanical properties are made on these alloys. While mechanical properties of magnesium are usually enhanced by alloying, corrosion properties may deteriorate. This paper is focused on the comparison of magnesium alloys AZ31 (3 wt. % Al, 1 wt. % Zn) and WE43 (4 wt. % Y, 3 wt. % Nd) which are considered for biomedical applications. Besides the type of alloying elements, the preparation process has also great impact on final mechanical and corrosion properties. Alloying elements may be dissolved in magnesium matrix or they can form intermetallic phases, which alter final properties. Microstructure, mechanical and corrosion properties of AZ31 and WE43 were studied and compared with pure magnesium.

scholarly journals Influence of Precipitation Hardening in Mg-Y-Nd on Mechanical and Corrosion Properties

JOM ◽  
2015 ◽  
Vol 68 (4) ◽  
pp. 1183-1190 ◽  
Author(s):  
P. Maier ◽  
R. Peters ◽  
C. L. Mendis ◽  
S. Müller ◽  
N. Hort
Keyword(s):  
Precipitation Hardening ◽  
Corrosion Properties ◽  
Mechanical And Corrosion Properties

scholarly journals Microstructure, Mechanical, Corrosion, and Ignition Properties of WE43 Alloy Prepared by Different Processes

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 728
Author(s):  
Drahomír Dvorský ◽  
Jiří Kubásek ◽  
Klára Hosová ◽  
Miroslav Čavojský ◽  
Dalibor Vojtěch
Keyword(s):  
Solid Solutions ◽  
Ignition Temperature ◽  
Processing Technique ◽  
Intermetallic Phases ◽  
Alloying Elements ◽  
Minor Effect ◽  
Corrosion Properties ◽  
Mechanical And Corrosion Properties ◽  
A Minor ◽  
We43 Alloy

This paper deals with the effect of microstructure condition on ignition temperature, mechanical and corrosion properties of commercial WE43 alloy prepared by various processing techniques including conventional casting, extrusion, and powder metallurgy methods such as spark plasma sintering. For different processing technique, differences in microstructures were observed, including different grain sizes, intermetallic phases, amount of alloying elements in the solid solutions, or specific structural elements. Mechanical and corrosion properties were improved especially by grain refinement. Precipitation from oversaturated solid solutions led to further improvement of mechanical properties, while corrosion resistance was just slightly decreased due to the fine and homogeneously distributed precipitates of Mg41Nd5. The obtained results indicate huge differences in ignition resistance based on the metallurgical state of the microstructure. An improved ignition resistance was obtained at the condition with a higher concentration of proper alloying elements (Y, Nd, Gd, Dy) in the solid solution and absence of eutectic phases in the microstructure. Thermally stable intermetallic phases had a minor effect on resulting ignition temperature.

scholarly journals Microstructure, Mechanical and Corrosion Properties of Mg-Gd-Zn Alloys

2013 ◽  
Vol 765 ◽  
pp. 28-32 ◽  
Author(s):  
Amirthalingam Srinivasan ◽  
Yuan Ding Huang ◽  
Chamini Lakshi Mendis ◽  
Hajo Dieringa ◽  
Carsten Blawert ◽  
...  
Keyword(s):  
Volume Fraction ◽  
High Volume ◽  
Dynamic Precipitation ◽  
Corrosion Properties ◽  
Corrosion Studies ◽  
Zn Content ◽  
The Matrix ◽  
Elongation To Failure ◽  
Mechanical And Corrosion Properties ◽  
Cast Condition

Microstructure, mechanical and corrosion properties of Mg-10Gd-2Zn and Mg-10Gd-6Zn (all in wt.%) were evaluated in the as-cast condition. The microstructures of both alloys contained (Mg, Zn)3Gd phase at the interdendritic regions and long period stacking ordered (LPSO) phase distributed in the matrix. The Mg-10Gd-6Zn alloy consisted of a high volume fraction of (Mg,Zn)3Gd intermetallic phases continuously distributed along the grain boundaries. The tensile properties, especially the elongation to failure of the Mg-10Gd-6Zn alloy were slightly lower than those of Mg-10Gd-2Zn. An enhancement in creep resistance was observed with Mg-10Gd-2Zn alloy with the post creep tested microstructure showing dynamic precipitation. Corrosion studies indicated that increased Zn content, from 2 to 6 % in Mg-10Gd alloys, significantly reduced the corrosion resistance.

scholarly journals Influence of Different Soaking Times at 1050 °C on the UT Response Due to Microstructure Evolution of 2205 Duplex Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 503
Author(s):  
Andrea Gruttadauria ◽  
Silvia Barella ◽  
Carlo Mapelli ◽  
Davide Mombelli
Keyword(s):  
Stainless Steel ◽  
Thermal Treatment ◽  
Duplex Stainless Steel ◽  
Energy Absorption ◽  
Microstructure Evolution ◽  
Wave Scattering ◽  
Volume Fraction ◽  
Thermal Treatments ◽  
Corrosion Properties ◽  
Mechanical And Corrosion Properties

Under standard conditions, DSS (duplex stainless steel) features differing amounts of ferrite and austenite, essentially depending on the thermal treatment performed. This study is focused on the ultrasonic tests (UTs) response of DSS 2205, as a function of the microstructure, in terms of austenite volume fraction and austenitic grains evolution owing to different soaking times at 1050 °C. UTs were carried out on several samples. The samples underwent varying thermal treatments characterized by a constant maintenance temperature with different soaking times that allowed for microstructure evolution and modification of the structural constituents’ fraction. The UTs have highlighted an attenuation trend with the response mainly dependent upon the wave scattering and energy absorption caused by the grain features. In particular, the peak of sound attenuation was shown to correspond with the microstructure, which featured a major amount of austenite (in terms of volume fraction and the grain dimensions) and the disappearance of austenitic precipitates within the ferritic matrix. In order to obtain less UT attenuation, without affecting the mechanical and corrosion properties, the soaking should last as little time as possible.

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