Effects of stabilization treatment on the precipitation behavior of β phase and stress corrosion for AA5383-H15 alloys

2019 ◽  
Vol 34 (14) ◽  
pp. 2554-2562 ◽  
Author(s):  
Yu-Chih Tzeng ◽  
Chun-Hsien Lin
Keyword(s):  
Stress Corrosion ◽  
Precipitation Behavior ◽  
Stabilization Treatment ◽  
Β Phase ◽  
Image Position

Abstract

The Metastable Phase Responsible for Hardenig in an Al-Mg Alloy Aged at 473K

2013 ◽  
Vol 748 ◽  
pp. 123-127 ◽  
Author(s):  
Koichiro Fukui ◽  
Ayaka Mori ◽  
Masanori Mitome ◽  
Mahoto Takeda
Keyword(s):  
Precipitation Hardening ◽  
Vickers Microhardness ◽  
Layer Structure ◽  
Metastable Phase ◽  
Mg Alloy ◽  
Stable Phase ◽  
Precipitation Behavior ◽  
Dsc Measurements ◽  
Β Phase ◽  
Phase Precipitate

The present work investigated precipitation behavior in an Al-17at%Mg alloy isothermally aged at 473K, by means of Vickers microhardness tests, DSC measurements and TEM observations. A quantitative analysis of DSC measurements revealed that the metastable β-phase precipitates mainly contribute to precipitation hardening of this alloy aged at 473K. The present STEM-EDX observations confirmed that the metastable β-phase precipitate has a layer structure with a composition similar to the stable phase (Al3Mg2).

The precipitation behavior of a pretwinned Mg–6Al–1Zn alloy and the effect on subsequent deformation

2014 ◽  
Vol 29 (18) ◽  
pp. 2141-2146 ◽  
Author(s):  
Yin Zhang ◽  
Tianmo Liu ◽  
Xuezheng Ding ◽  
Shun Xu ◽  
Jiejun He ◽  
...  
Keyword(s):  
Precipitation Behavior ◽  
Subsequent Deformation ◽  
Image Position

Abstract

Intergranular Corrosion and Stress Corrosion Cracking of Sensitised AA5182

2006 ◽  
Vol 519-521 ◽  
pp. 641-646 ◽  
Author(s):  
Alison J. Davenport ◽  
Yudie Yuan ◽  
Rajan Ambat ◽  
Brian J. Connolly ◽  
Martin Strangwood ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Intergranular Corrosion ◽  
Corrosion Cracking ◽  
Critical Factors ◽  
Phase Precipitation ◽  
Β Phase ◽  
Grain Boundary Plane ◽  
Corrosion Susceptibility ◽  
Variable Precipitation

AA5182 (Al-4.5 wt% Mg) can become susceptible to intergranular corrosion (IGC) with time at moderately elevated service temperatures owing to precipitation of Mg-rich β-phase at grain boundaries, which can lead to stress corrosion cracking (SCC). The IGC and SCC susceptibility of AA5182 was found to depend strongly on sensitisation heat treatments. AFM and TEM studies demonstrated that the degree of precipitation and thus susceptibility to attack for a boundary can be related to its crystallographic misorientation. Low angle boundaries (<20°) are most resistant to attack as they do not show β-phase precipitation. However, higher angle boundaries show highly variable precipitation and corrosion susceptibility: critical factors are the grain boundary plane and precipitate/matrix crystallographic relationship.

scholarly journals Influence of Solution Treatment Time on Precipitation Behavior and Mechanical Properties of Mg-2.0Nd-2.0Sm-0.4Zn-0.4Zr Alloy

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5037
Author(s):  
Tao Ma ◽  
Sicong Zhao ◽  
Liping Wang ◽  
Zhiwei Wang ◽  
Erjun Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Treatment Time ◽  
Solution Treatment ◽  
Basal Plate ◽  
Aged Alloy ◽  
Precipitation Behavior ◽  
Β Phase ◽  
Solution Treated ◽  
Strengthening Phases

The effect of solution treatment time on the microstructure and mechanical properties of aged the Mg-2.0Nd-2.0Sm-0.4Zn-0.4Zr (wt.%) alloy were investigated to give full play to the performance of the alloy. As the solution treatment time increased from 2 h to 12 h at 788 K, the grain size of the solution-treated alloy significantly increased, and the network-like β-Mg12(Nd, Sm, Zn) phase gradually dissolved into the α-Mg matrix. It should be noted that no obvious residual β phase can be observed when the solution treatment time was more than 8 h. After the solution-treated alloy was further aged at 473 K for 18 h, a large number of nanoscale precipitates were observed in the α-Mg matrix. The solution treatment time was 2 h, the α-Mg matrix mainly consisted of spherical-shaped and basal plate-shaped precipitates. Upon the increase of solution treatment time to 8 h, the key strengthening phases transformed from spherical-shaped precipitates and basal plate-shaped precipitates to prismatic plate-shaped β′ precipitates. The orientation relationship between β′ precipitates and α-Mg matrix was (1¯10)β′ // (11¯00)α and [112]β′ // the [224¯3]α. Further increasing of solution treatment time from 8 h to 12 h, the key strengthening phases mainly were still β′ precipitates. The solution treatment of aged alloy was carried out at 788 K for 8 h, which achieved optimal ultimate tensile strength (UTS) of 261 ± 4.1 MPa, yield strength (YS) of 154 ± 1.5 MPa, and elongation of 5.8 ± 0.1%, respectively.

Development of Fit-for-Purpose Austenitic Stainless Steels With High Polythionic Acid Stress Corrosion Resistance

2017 ◽  
Author(s):  
Takahiro Osuki ◽  
Masahiro Seto ◽  
Hirokazu Okada ◽  
Masayuki Sagara ◽  
Satoshi Matsumoto ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stainless Steels ◽  
Acid Corrosion ◽  
Acid Stress ◽  
Austenitic Stainless Steels ◽  
Total Acid ◽  
Term Operation ◽  
Stabilization Treatment ◽  
Fit For Purpose

In the process units with Polythionic Acid Stress Corrosion Cracking (PTA-SCC) such as hydrotreater or hydrocracker, the neutralization treatment like soda ash washing and/or PWHT, Post Weld Heat Treatment, are conducted for stabilized austenitic stainless steels of TP321H or TP347H to mitigate the potential of PTA-SCC. 347AP, the proprietary version of Type 347LN, is remarkable for the possibility to save the fabrication and turnaround cost by the elimination of the neutralization treatment and/or PWHT and its reliability to PTA-SCC resistance without PWHT and neutralization was proven by the long-term service experience. However it has not been investigated the difference between 347AP and TP347H for the Stress Relaxation (SR) cracking resistance of welded joint required for the long term operation at elevated temperature. On the other hand, in atmospheric distillation units and vacuum distillation units using the crude containing high Total Acid Number (TAN), the resistances to both Naphthenic Acid Corrosion (NAC) and PTA-SCC are required by elevating the design temperature. Therefore, Fit-for-purpose austenitic stainless steels with high PTA-SCC resistance without stabilization treatment are required for the complicated environment with the variation of temperature, pressure and fluid in petroleum refinery process using the crude containing high S content. In this study, SR cracking susceptibility of 347AP is investigated and it is found that 347AP has lower SR cracking susceptibility than TP347H without stabilization treatment. Next, in order to improve NAC resistance compared with 347AP, the effect of Mo, Cu and W contents to NAC are investigated based on 347AP, and it is clarified that the increase of Mo content greater than 3% is the most effective to improve NAC resistance. Moreover, the conventional welding filler with the similar NAC and PTA-SCC resistances to base metal is investigated, and it is reported that ER NiCrCoMo-1 filler was recommended for the welding fabrication of Fit-for-purpose austenitic stainless steels with high PTA-SCC resistance.

Effects of annealing temperature on stress corrosion susceptibility of AA5083–H15 alloys

2016 ◽  
Vol 31 (8) ◽  
pp. 1163-1170 ◽  
Author(s):  
Chun-Hung Yen ◽  
Chih-Ting Wu ◽  
Yen-Hao Chen ◽  
Sheng-Long Lee
Keyword(s):  
Stress Corrosion ◽  
Annealing Temperature ◽  
Corrosion Susceptibility ◽  
Image Position

Abstract

scholarly journals Effects of the amount of Mg on the precipitation behavior of β phase and its modeling in Al–Mn–Mg alloys

2020 ◽  
Vol 70 (2) ◽  
pp. 43-50
Author(s):  
Takashi Shinozaki ◽  
Jun Shimojo ◽  
Hiroshi Akamatsu ◽  
Katsushi Matsumoto ◽  
Toshihiko Shinya ◽  
...  
Keyword(s):  
Mg Alloys ◽  
Precipitation Behavior ◽  
Β Phase

Significant α-phase growth confinement in Grade 4 titanium and substantial β-phase refinement in Grade 7 titanium

2014 ◽  
Vol 4 (4) ◽  
pp. 183-188 ◽  
Author(s):  
M. Yan ◽  
M. Qian ◽  
T.T. Song ◽  
M.S. Dargusch ◽  
X.S. Wei
Keyword(s):  
Phase Growth ◽  
Β Phase ◽  
Α Phase ◽  
Image Position

Abstract

Effect of Heat Treatment on Phase Transformation and Precipitation Behavior of Cu40Zn-1.0 Wt% Ti Brass via Powder Metallurgy

2011 ◽  
Vol 233-235 ◽  
pp. 2732-2735 ◽  
Author(s):  
Shu Feng Li ◽  
Hisashi Imai ◽  
Akimichi Kojima ◽  
Yoshiharu Kosaka ◽  
Koji Yamamoto ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Powder Metallurgy ◽  
Solid Solubility ◽  
Chemical Potential ◽  
Volume Fraction ◽  
Powder Metallurgy Method ◽  
Micro Hardness ◽  
Precipitation Behavior ◽  
Β Phase

The effect of heat treatment on phase transformation, precipitation behavior and micro-hardness response of Cu40Zn-1.0Ti brass was investigated via powder metallurgy method. The volume fraction of α phase increased with elevated temperature, equaled to that of β phase at 400 °C, and reached to a maximum value of 55.9% at 500 °C. The solid solubility of Ti in Cu40Zn brass matrix decreased with elevated heat treatment temperature, showed high chemical potential for precipitates reaction in Cu40Zn brass. The micro-hardness of the BS40-1.0Ti brass was primarily dependent on the solid solubility of Ti, but also dependent on the phase ratio of α and β phase.

Sign in / Sign up

Export Citation Format

Share Document