Effect of homogenization temperature and soaking time on the microstructure and corrosion properties of a twin roll casted AA3003

CORROSION ◽  
10.5006/3813 ◽  
2021 ◽  
Author(s):  
Donovan Verkens ◽  
Reynier Revilla ◽  
Mert Günyüz ◽  
Cemil Işıksaçan ◽  
Herman Terryn ◽  
...  

The AA3003 alloy is widely used as fin material in heat exchangers. The life time of these heat exchangers is mostly determined by their corrosion properties. Twin roll casting (TRC) of AA3003 material is known to often result in the formation of a macrosegregation area of alloying elements towards the centre plane of the casted strip (centre line segregation = CLS). Considering the potential exposure of cross-sectional areas of TRC material in the heat exchanger fin application, and the relatively high corrosion susceptibility of the CLS, the study of this region is of key importance to understand the microstructural effects on the resulting corrosion mechanisms and kinetics for these materials. Typically the alloys are homogenized to bring the microstructures closer to an equilibrium state, but the impact of this heat treatment on the corrosion properties is insufficiently studied. Therefore, this study investigates the effect of different homogenization procedures on the corrosion properties of the CLS and the interaction of the intermetallic particles with the surrounding aluminium matrix. This work shows that the pitting corrosion resistance is greatly dependent on the homogenization temperature, with better corrosion resistance obtained with higher temperature, especially near the CLS. This difference in corrosion behaviour is completely attributed to a difference in microstructure and not to an oxide layer effect. Furthermore, it is observed that not only temperature will have a large influence on the corrosion resistance, but duration of the heat treatment as well.

2021 ◽  
Author(s):  
Mingzhen Xiu ◽  
Yong Teck Tan ◽  
Srinivasan Raghavan ◽  
Min Hao Goh ◽  
Mui Ling Sharon Nai

Abstract There has been limited studies on corrosion behaviour of post-processed Electron Beam Melted (EBM) Ti6Al4V, given that the factors affecting corrosion resistance of AM Ti6Al4V remain unclear. This paper proposes using heat treatment method to improve the pitting corrosion resistance of EBM Ti6Al4V. Different treatment profiles alter the microstructure of EBM Ti6Al4V. A clear trend is observed between microhardness and α lath width. As-printed EBM Ti6Al4V exhibits an inferior pitting potential, while heat treatment provided a significant improvement in the corrosion resistance. This study finds that the β phase fraction is a better indicator than the α lath width for pitting corrosion resistance. Solution air-cooled & ageing heat treated EBM Ti6Al4V exhibits good mechanical and corrosion properties, and even performs better than commercial cast Ti6Al4V.


2007 ◽  
Vol 555 ◽  
pp. 559-563 ◽  
Author(s):  
Kemal Delijić ◽  
V. Asanović ◽  
Dragan Radonjić

The paper deals with the effects of thermo-mechanical processing parameters on the properties of two Al-Fe-Si foil alloys. Two twin roll cast alloys with high Fe/Si ratios (Fe/Si≈6) were processed under different combinations of homogenization, deformation and annealing treatments. The influence of small additions of manganese on the mechanical behavior and plastic anisotropy of sheets in hardening and annealing conditions are described. The corrosion resistance of tested sheets in chloride ambience is also presented, because this type of Al foils is dominantly used in the packaging (food) industry and heat exchangers.


2013 ◽  
Vol 690-693 ◽  
pp. 2673-2677
Author(s):  
Kyung Man Moon ◽  
Mun Jin Nam ◽  
Yeon Chang Lee ◽  
Yun Hae Kim ◽  
Jae Hyun Jeong

Recently, the fuel oil of diesel engines of marine ships is being changed to heavy oil of low quality as the oil price is getting higher and higher. Therefore, the wear and corrosion in all parts of the engine, such as cylinder liner, piston crown, and spindle and seat ring of exhaust valves has predominantly increased. Thus, the repair welding of the piston crown is a unique method to prolong its life in a economical point of view. In this case, filler metals with a high corrosion and wear resistance are mainly being used for repair welding. However, the piston crown on the ships job site is often actually being welded with mild filler metals. Therefore, in this study, mild filler metals, such as E4301, E431316, and E4316, were welded to the SS401 steel as the base metal, and the corrosion properties of their weld metals with and without post weld heat treatment were investigated with some electrochemical methods in 0.1% H2SO4 solution. The weld metal welded with E4301 filler metal exhibited the best corrosion resistance among the filler metals in the case of no heat treatment, however, its resistance was considerably decreased due to the post weld heat treatment (annealing:625°C, 2hr). In particular, the weld metal of E4316 exhibited relatively a good corrosion resistance by the post weld heat treatment.


2021 ◽  
Vol 5 (10) ◽  
pp. 280
Author(s):  
Omolayo Michael Ikumapayi ◽  
Esther T. Akinlabi ◽  
Olayinka Oluwatosin Abegunde ◽  
Precious Ken-Ezihuo ◽  
Henry A. Benjamin ◽  
...  

Corrosion is one of the leading sources of material failure and deterioration in society. Scholars have proposed different techniques to mitigate corrosion. This research study explores and validates one of these techniques. An Aluminium metal matrix (AMC) was produced using the stir casting method with various weight percentages of AgNp and CaCO3 reinforcements. Heat treatment was performed on the samples to enhance the metallurgical and corrosion properties of the materials. The corrosion rate of the AMC samples was tested in different corrosive media (neutral and acidic) with different concentrations using the weight loss analysis technique for several days. It was observed that the corrosion rate of the AMC relies on the nature of the electrolyte and the percentage concentration of this electrolyte. The heat treatment improves the corrosion resistance of the AMC samples. In addition, an increase in the % weight composition of the reinforcement (AgNp + CaCO3) results in a reduction in the corrosion rate of the AMC in both corrosive media. The optimal %weight composition was found to be 4% for the hybrid reinforcement of AgNp + CaCO3 and 6% for the CaCO3 reinforcement in both the untreated and heat-treated samples.


2019 ◽  
Vol 9 (9) ◽  
pp. 1092-1099
Author(s):  
Fenghong Cao ◽  
Chang Chen ◽  
Zhenyu Wang

The corrosion characteristics and corrosion mechanism of the extruded ZK80 alloy with different states soaking in 3.5% NaCl solution at room temperature were analyzed via OM, SEM, EDS, XRD and static weightlessness method and other experimental analysis methods. The results show that when the aging temperature is constant, and the corrosion rate decreases with the lengthen of aging time, while when the corrosion time is constant, the corrosion rate increases with the increase in aging time. Appropriate aging treatment not only refines the grain of the alloy, but also precipitates the Mg–Zn phase which can effectively prevent the corrosion process and improve the anti-corrosion properties of the alloy. The main corrosion characteristics of the alloy are filamentary corrosion and pitting corrosion.


2015 ◽  
Vol 658 ◽  
pp. 76-80 ◽  
Author(s):  
Amporn Wiengmoon ◽  
Torranin Chairuangsri ◽  
John T.H. Pearce

Effects of destabilisation heat treatment on microstructure, hardness and corrosion resistance of 18wt.%Cr and 25wt.%Cr irons have been investigated. The as-cast samples were heat-treated by destabilisation at 1000°C for 4 hour and then air cooling. The microstructure was investigated by light microscopy and scanning electron microscopy. The results show that the as-cast microstructure in 18wt.%Cr iron consists of pearlite, formed by decomposition of primary dendritic austenite, plus eutectic structure. In the 25wt.%Cr iron with lower hardness, the microstructure consists of primary dendritic austenite plus eutectic structure. The austenite had partly transformed to martensite, especially at areas adjacent to eutectic carbides. After destabilisation, the microstructure of both irons consists of eutectic and secondary carbides in a martensite matrix giving increased hardness. It was found that corrosion resistance of the irons was improved after destabilisation. The 25wt.%Cr showed superior corrosion resistance than the 18wt.%Cr iron due to greater residual Cr in the matrix to encourage passivity.


1983 ◽  
Vol 28 ◽  
Author(s):  
B.-O. Reinders ◽  
H. W. Bergmann

ABSTRACTThe corrosion behaviour in liquid electrolytes were investigated for some Fe- and Ni-based metallic glasses varying pH-value, electrolyte temperature and heat treatment. For some (Fe100-xMx)83B17 glasses the high temperature oxidation behaviour was studied.


2014 ◽  
Vol 941-944 ◽  
pp. 1585-1588
Author(s):  
Zu Xiao Yu ◽  
De Tao Zheng ◽  
Hong Guo ◽  
Yong Liu ◽  
Yuan Liang Luo ◽  
...  

To improve the wear resistance and anti-corrosion properties of the aluminum, the electroless plating Ni-W-Mo-P alloy on the aluminum is necessary. The influences of heat treatment and additives (stabilizers) on the porosity, deposition rate, corrosion current, corrosion potential, microhardness and wear resistance of electroless plating Ni-W-Mo-P alloy coating, were investigated using electrochemical methods, etc. The results show that the deposition rate and anti-corrosion properties of electroless plating Ni-W-Mo-P are improved when the stabilizers, including KI (1mg/L) and “KIO3 (1mg/L) + Pb (Ac)2 (1mg/L)”, are added into bath, respectively. In addition, the maximum hardness (902 HV) and good wear resistance of Ni-W-Mo-P coatings are obtained when heated at 400°C (1h). However, its corrosion resistance is worse. Its microhardness is also obviously improved after heated at 200°Cfor 6 h, and the microhardness reaches to 950 HV.


2011 ◽  
Vol 282-283 ◽  
pp. 774-778
Author(s):  
Zhi Jing Peng ◽  
Ying Chen ◽  
Xue Yuan Nie

Ceramic oxide coatings were prepared on an aluminum A356 alloy by a plasma electrolytic oxidation (PEO) technique under unipolar, bipolar and duplex unipolar/bipolar current modes. Cross-sectional morphologies of the coatings were studied using a scanning electron microscope (SEM). The corrosion behavior of the coated and uncoated samples was evaluated in ethanol-gasoline E85 fuels through potentiodynamic polarization and zero resistance ammeter (ZRA) testing methods. The results indicated that all the coatings had a better corrosion resistance compared to the uncoated substrate. The unipolar current mode created the PEO coating with a thicker coating microstructure and thus a better corrosion resistance, compared to a bipolar current mode. The duplex treatments of unipolar/bipolar or bipolar/unipolar current modes produced the best performance of the coatings against galvanic corrosions caused by a steel/Al coupling in the E85 fuel medium.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 636
Author(s):  
Dorota Rylska ◽  
Bartłomiej Januszewicz ◽  
Grzegorz Sokołowski ◽  
Jerzy Sokołowski

The procedure of ceramics fusion to cobalt–chromium (Co–Cr) base dental crowns affects their corrosion behavior and biological tolerance. This study’s purpose was to comparatively evaluate the effect of heat treatment (HT) applicable for dental ceramics firing on the corrosion properties among Co–Cr base alloys fabricated via different methods: casting (CST), milling soft metal and post sintering (MSM), and selective laser melting (SLM). All specimens were subjected to a heat treatment corresponding to a full firing schedule. The microstructure and elemental composition of oxidized surfaces were investigated by scanning electron microscopy and energy dispersive spectroscopy. Corrosion properties were examined by electrochemical potentiodynamic polarization tests. The values of jcorr, Ecorr, Rp, and breakdown potential Ebr were estimated. The oxide layers formed during the HT process corresponded to the composition of the original alloys’ structure. Among the thermal treated alloys, SLM showed the highest corrosion resistance, followed by the MSM and CST. This may be attributed to uniform distribution of alloying elements in homogenous structure and to the reduced porosity, which enhances corrosion resistance and decreases the risk of crevice corrosion. The overall corrosion behavior was strongly influenced by the segregation of alloying elements in the microstructure, thus, is directly determined by the manufacturing method.


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