Influence of final annealing temperature on the microstructural evolution and corrosion resistance of a Sandwich multi-layered aluminum sheet

2018 ◽  
Vol 6 (2) ◽  
pp. 026536 ◽  
Author(s):  
Zhipeng Yuan ◽  
Yiyou Tu ◽  
Han He ◽  
Ting Yuan ◽  
Quancheng Zhang ◽  
...  
2019 ◽  
Vol 944 ◽  
pp. 488-498
Author(s):  
Zhong Bo Yang ◽  
Jing Jing Liao ◽  
Shao Yu Qiu ◽  
Zhu Qing Cheng ◽  
Hong Liu ◽  
...  

The corrosion resistance of SZA-6 zirconium alloy(Zr-0.5Sn-0.5Nb-0.3Fe-0.015Si) cladding tubes finally annealed at 480°C, 510°C and 560°C were studied by static autoclave in 360°C/18.6 MPa pure water and 360°C/18.6 MPa/0.01 mol/L LiOH aqueous solution. The microstructure of the samples before and after corrosion were analyzed by EBSD, TEM and SEM. The results showed that the corrosion weight gains of the three SZA-6 alloy samples were lower than that of Zr-4 alloy after 500 days corrosion in both hydrochemical mediums. After long-term corrosion, the corrosion weight gains of SZA-6 alloy in pure water and LiOH aqueous solution increased obviously with the final annealing temperature, while the corrosion weight gain of unstressed Zr-4 alloy was higher than that of recrystallized under the same condition. With the increase of the final annealing temperature, the high-angle grain boundaries in the alloy larger than 15° became more and recrystallization degree also increased. The Second Phase Precipitates (SPPs) were fine, uniform, and dispersively distributed with an average diameter of about 120 nm. Although the size and distribution of the SPPs were similar, the Nb/Fe ratio in the SPPs increased. The long-term corrosion weight gain of zirconium alloy was related to the number of parallel cracks in the oxide film and the uneven growth degree of the oxide film on the interface of the oxide film/matrix. The corrosion resistance of the alloy in two hydrochemical mediums was related to the degree of recrystallization and the content of Nb in the SPPs. Increasing the final annealing temperature would promote the formation of fine and uniform recrystallized grains, which was benefit to the corrosion resistance, but at the same time it would reduce the content of solid solution Nb in the αZr matrix, which in turn would be detrimental to the corrosion resistance.


1997 ◽  
Vol 5 (1-6) ◽  
pp. 171-177 ◽  
Author(s):  
H.K. Liu ◽  
R. Bhasale ◽  
Y.C. Guo ◽  
J. Horvat ◽  
B. Zeimetz ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ihsan-ul-Haq Toor

The corrosion behavior of two specially designed austenitic stainless steels (SSs) having different Nickel (Ni) and Manganese (Mn) contents was investigated. Prior to electrochemical tests, SS alloys were solution-annealed at two different temperatures, that is, at 1030°C for 2 h and 1050°C for 0.5 h. Potentiodynamic polarization (PD) tests were carried out in chloride and acidic chloride, whereas linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) was performed in 0.5 M NaCl solution at room temperature. SEM/EDS investigations were carried out to study the microstructure and types of inclusions present in these alloys. Experimental results suggested that the alloy with highest Ni content and annealed at 1050°C/0.5 hr has the highest corrosion resistance.


2021 ◽  
Vol 45 (1) ◽  
pp. 69-74
Author(s):  
Tassi Hocine ◽  
Zidelmel Sami ◽  
Allaoui Omar

In the present investigation, some electrochemical properties of dual phase X70 steels with different martensite morphologies which have undergone boriding were studied. To obtain a variety of martensite morphologies, Direct Quenching (DQ), Intermediate Quenching (IQ) and Step Quenching (SQ) heat treatments were applied at an intercritical annealing temperature (IAT) of 760℃. The treatment (DQ) allowed the formation of fine martensite evenly distributed in the ferrite matrix. (IQ) treatment showed the formation of martensite along the ferrite / ferrite grain boundaries. In contrast, treatment (SQ) induced the formation of a banded morphology of martensite and ferrite. The realization of borides on X70 (DP) steel was carried out in a powder mixture containing 5% of B4C as source of boron, 5% of NaBF4 as activator and 90% of SiC as diluent at 950℃ for a period of time from 4 h. The corrosion behavior of X70 (DP) steel has been explored by the Tafel extrapolation method in a 5 wt. % H2SO4 solution. The corrosion resistance of steel which has undergone boriding (BDP) is higher than that of steel which has not undergone it (DP).


2017 ◽  
pp. 1303-1326
Author(s):  
Prasanna Gadhari ◽  
Prasanta Sahoo

Electroless nickel coatings are widely popular in various industrial sectors due to their excellent tribological properties. The present study considers optimization of coating parameters along with annealing temperature to improve microhardness and corrosion resistance of Ni-P-TiO2 composite coatings. Grey relational analysis is used to find out the optimal combination of coating parameters. From the analysis, it is confirmed that annealing temperature of the coating has the most significant effect and amount of titanium particles in the coating has some significant effect on corrosion properties of the coating. The same trend is observed in case of combined study of corrosion behavior and microhardness. The surface morphology, phase transformation and the chemical composition are examined using scanning electron microscopy, X-ray diffraction analysis and energy dispersive analysis respectively. The Ni-P-TiO2 composite coating revealed nodular structure with almost uniform distribution of titanium particles and it turns in to crystalline structure after heat treatment.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 294
Author(s):  
Shuang Liu ◽  
Chaohua Yue ◽  
Xi Chen ◽  
Qiuhua Zhu ◽  
Yiyou Tu

The pitting corrosion resistance of S32750 super duplex stainless steel, annealing treated at temperatures of 950–1200 °C for 20–60 min, was investigated using potentiodynamic polarization tests. The results show that the volume fractions of ferrite in the S32750 duplex stainless steel increased from 48.9% to 68.4% as annealing temperatures increased from 950 to 1200 °C. The pitting potential of the sample increased first and then decreased from an annealing temperature of 950 to 1050 °C, and the highest pitting potential was observed after annealing at 1050 °C for 35 min. The pitting corrosion resistance of S32750 stainless steel is due to the combination of pitting resistance equivalent number (PREN) value, phase fraction and grain boundary area fraction, and the imbalance of corrosion potential.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Van Tuan Nguyen ◽  
Quy Le Thu ◽  
Tuan Anh Nguyen ◽  
Quoc Cuong Ly ◽  
Ly Pham Thi ◽  
...  

This study presents the effect of heat treatment on porosity, phase composition, microhardness, and wear and corrosion resistances of the thermal sprayed NiCr20 coating after sealing with aluminum phosphate. The annealing temperatures were varied in a range of 400 to 1000°C. The obtained results indicated the porosity of coating decreased with increasing the annealing temperature. After treatment at temperatures in range of 800-1000°C, more than 90% of initial pores in the coating were successfully filled with the sealants. The XRD data revealed not only the formation of new phases of other compounds, but also the interaction between coating and sealant. After heat treatment, wear resistance of coating was 12 times higher than that without heat treatment. The corrosion test in H2SO4 solution indicated that the presence of sealant in coatings increased their corrosion resistance. From these findings, application of these NiCr20 coatings to protect steel against wear and corrosion appears very promising.


1998 ◽  
Vol 513 ◽  
Author(s):  
B. K. Lee ◽  
A. J. Steckl ◽  
J. M. Zavada ◽  
R. G. Wilson

ABSTRACTThe effect of the incorporation and annealing of deuterium in 3C-SiC on its photoluninescence is reported. A 3C-SiC crystal has been implanted with 100 keV deuterium and subsequently annealed at temperatures between 1015 °C and 1220 °C for 1 to 5 minutes. SIMS depth profiles indicate hydrogen is strongly trapped by defects generated through ion bombardment, but a gradual damage repairing occurs during annealing. Photoluminescence was measured with 488 nm Ar laser excitation for sample temperatures from 89 K to 400 K. The PL peak wavelength of 540 nm at room temperature has shifted to 538 nm at 89 K. The peak PL intensity decreases with measurement temperature while its full width at half maximum (FWHM) exhibits an increasing trend. PL data were taken at five annealing stages. The post-implantation peak PL intensity and its integrated area increase initially with annealing temperature and time. After the final annealing at 1218 °C for 2 minute, PL intensity and its integrated area exhibit a decrease in level.


Sign in / Sign up

Export Citation Format

Share Document