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Yiming Jiang - One of the best experts on this subject based on the ideXlab platform.
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effect of a brief post weld heat treatment on the microstructure evolution and Pitting Corrosion of laser beam welded uns s31803 duplex stainless steel
Corrosion Science, 2012Co-Authors: Yanze Yang, Zhiyu Wang, Yiming Jiang, Jufeng Hong, Laizhu JiangAbstract:Abstract The effect of laser-beam welding and subsequent short-time post-weld heat treatment at different temperatures and holding time on microstructure evolution and Pitting Corrosion behavior of UNS S31803 duplex stainless steel was investigated. The results showed the as-welded joint displayed impaired Pitting Corrosion Resistance and that Pitting preferentially occurred at ferrite grain in the fusion zone. Short-time heat treatment enhanced the Pitting Corrosion Resistance of welded joint. Optimal post-weld heat treatment of 3 min heat treatment at 1080 °C was identified at which the joint restored the Pitting Corrosion Resistance lost during welding process.
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influence of cooling rate on microstructure evolution and Pitting Corrosion Resistance in the simulated heat affected zone of 2304 duplex stainless steels
Corrosion Science, 2012Co-Authors: Lindou Chen, Zhiyu Wang, Jin Li, Yiming JiangAbstract:Abstract Pitting Corrosion Resistance of 2304 duplex stainless steel heat-affected zone with different cooling rates has been studied by potentiostatic critical Pitting temperature (CPT) in 1.0 M NaCl. The results showed that, as cooling rate decreased from 100 to 10 °C/s in the temperature range of 1350–800 °C, the austenite fraction increased from 27.8% to 35.7%, and the CPT value increased from 14 to 19 °C. The morphologies after the CPT tests showed Pitting occurred preferentially in the ferrite phase for all specimens. Moreover, relationship between Pitting Corrosion Resistance and microstructure evolution was further discussed.
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microstructural evolution and Pitting Resistance of annealed lean duplex stainless steel uns s32304
Nuclear Engineering and Design, 2012Co-Authors: Yiming Jiang, Dong Han, Ziying Zhang, Chong ShiAbstract:Abstract The effect of annealing temperature in the range from 1000 to 1200 °C on the Pitting Corrosion behavior of duplex stainless steel UNS S32304 was investigated by the potentiodynamic polarization and potentiostatic critical Pitting temperature techniques. The microstructural evolution and pit morphologies were studied using a scanning electron microscopy with energy dispersive X-ray spectroscopy. The results demonstrated that the nucleation of metastable pits transformed from austenite phase to ferrite phase with the increasing annealing temperature. As the annealing temperature increased, the Pitting Corrosion Resistance firstly increased and then decreased. The highest Pitting Corrosion Resistance was obtained at 1080 °C with the highest critical Pitting temperature value and Pitting nucleation Resistance. The results could be well explained by the microstructural evolution of ferrite and austenite phases induced by annealing treatment.
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influence of welding thermal cycles on microstructure and Pitting Corrosion Resistance of 2304 duplex stainless steels
Corrosion Science, 2012Co-Authors: Hua Tan, Bo Deng, Zhiyu Wang, Yiming Jiang, Yanze Yang, Hongmei SongAbstract:Abstract Different welding thermal cycles from single-pass to triple-pass were performed on two kinds of 2304 duplex stainless steel through Gleebe thermal–mechanical simulator. The corresponding microstructure was observed, while the Pitting Corrosion Resistance was investigated in 1.0 M NaCl by potentiostatic critical Pitting temperature (CPT). The results showed that single-pass welding deteriorated microstructure and Pitting Corrosion Resistance significantly. As the welding pass increased, the ferrite content decreased and CPT increased. However, CPT was still lower than that of the base metal. Nitride precipitated at the boundary between ferrite and austenite phase for low-alloyed 2304 after the single-pass welding thermal cycle.
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annealing temperature effect on the Pitting Corrosion Resistance of plasma arc welded joints of duplex stainless steel uns s32304 in 1 0 m nacl
Corrosion Science, 2011Co-Authors: Hua Tan, Lindou Chen, Zhiyu Wang, Yiming Jiang, Dong Han, Jufeng Hong, Laizhu JiangAbstract:Abstract Pitting Corrosion Resistance of 2304 duplex stainless steels after autogenous plasma-arc welding and subsequent short-time post-weld heat treatment at different temperatures, determined by critical Pitting temperature in 1.0 M NaCl solution, has been investigated. The results showed that the as-welded joint displayed impaired Pitting Corrosion Resistance and that Pitting preferentially occurred at ferrite grain in heat-affected zone near the fusion line. Short-time annealing treatment at 1020–1120 °C has a beneficial effect on the Pitting Corrosion Resistance of welded joint. The most favorable annealing temperature for the analyzed welded joints was found to be 1080 °C, at which the joint restored the Pitting Corrosion Resistance lost during welding entirely.
Sasha Omanovic - One of the best experts on this subject based on the ideXlab platform.
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the effect of surface roughness on the efficiency of the cyclic potentiodynamic passivation cpp method in the improvement of general and Pitting Corrosion Resistance of 316lvm stainless steel
Materials Letters, 2008Co-Authors: Abdullah Shahryari, Walid Kamal, Sasha OmanovicAbstract:Abstract The influence of surface roughness on the efficiency of a cyclic potentiodynamic passivation (CPP) method employed to increase the general and Pitting Corrosion Resistance of 316LVM stainless steel was investigated. The results show that a decrease in surface roughness of both the surface on which the passive film was formed naturally and by the CPP method, results in an increase in general Corrosion Resistance of the material, while for the CPP-modified surface, a notable increase in Pitting Corrosion Resistance was also observed. It was further demonstrated that the CPP method is highly effective in increasing the general and Pitting Corrosion Resistance of 316LVM, and that its efficiency does not depend on the surface roughness.
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electrochemical formation of highly Pitting resistant passive films on a biomedical grade 316lvm stainless steel surface
Materials Science and Engineering: C, 2008Co-Authors: Abdullah Shahryari, Sasha Omanovic, J A SzpunarAbstract:Abstract The results discussed in the paper demonstrate that a significant improvement in Pitting Corrosion Resistance of a biomedical grade 316LVM stainless steel can be achieved by electrochemically forming highly-protective passive oxide films on the material's surface, under cyclic potentiodynamic polarization conditions. The film formed in a sodium nitrate electrolyte is completely resistant to Pitting Corrosion in simulating physiological solutions even at high temperatures (60 °C), and after sterilization. The high Pitting Resistance of the electrochemically-formed films was explained on the basis of their semiconducting properties. Namely, the enrichment of the outer part of the electrochemically formed passive film with Cr(VI)-species results in a decrease in the density of oxygen vacancies, which act as Pitting initiation sites, and their ‘replacement’ by metal vacancies formed by the electrochemical oxidation of Cr(III) to Cr(VI). In this configuration, the outer Cr(VI)-rich oxide layer behaves as cation selective, which results in the increased Pitting Corrosion Resistance of the film. The simple electrochemical passivation technique discussed in the paper can be efficiently used to form highly Pitting resistant passive films on 316LVM-built medical implant devices of any geometry.
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improvement of Pitting Corrosion Resistance of a biomedical grade 316lvm stainless steel by electrochemical modification of the passive film semiconducting properties
Electrochemistry Communications, 2007Co-Authors: Abdullah Shahryari, Sasha OmanovicAbstract:Abstract In the present paper we show that a significant improvement in Pitting Corrosion Resistance of a biomedical grade stainless steel, 316LVM, can be achieved by the formation of a surface passive oxide film under cyclic potentiodyanamic polarization (passivation) conditions. A complete absence of Pitting in physiological simulating solutions was demonstrated, while the electrochemically formed passive film maintained its very high Pitting Resistance even at higher chloride concentrations in the bulk solution. The improvement in the film’s Pitting Corrosion Resistance was correlated with its semiconducting properties.
Abdullah Shahryari - One of the best experts on this subject based on the ideXlab platform.
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the effect of surface roughness on the efficiency of the cyclic potentiodynamic passivation cpp method in the improvement of general and Pitting Corrosion Resistance of 316lvm stainless steel
Materials Letters, 2008Co-Authors: Abdullah Shahryari, Walid Kamal, Sasha OmanovicAbstract:Abstract The influence of surface roughness on the efficiency of a cyclic potentiodynamic passivation (CPP) method employed to increase the general and Pitting Corrosion Resistance of 316LVM stainless steel was investigated. The results show that a decrease in surface roughness of both the surface on which the passive film was formed naturally and by the CPP method, results in an increase in general Corrosion Resistance of the material, while for the CPP-modified surface, a notable increase in Pitting Corrosion Resistance was also observed. It was further demonstrated that the CPP method is highly effective in increasing the general and Pitting Corrosion Resistance of 316LVM, and that its efficiency does not depend on the surface roughness.
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electrochemical formation of highly Pitting resistant passive films on a biomedical grade 316lvm stainless steel surface
Materials Science and Engineering: C, 2008Co-Authors: Abdullah Shahryari, Sasha Omanovic, J A SzpunarAbstract:Abstract The results discussed in the paper demonstrate that a significant improvement in Pitting Corrosion Resistance of a biomedical grade 316LVM stainless steel can be achieved by electrochemically forming highly-protective passive oxide films on the material's surface, under cyclic potentiodynamic polarization conditions. The film formed in a sodium nitrate electrolyte is completely resistant to Pitting Corrosion in simulating physiological solutions even at high temperatures (60 °C), and after sterilization. The high Pitting Resistance of the electrochemically-formed films was explained on the basis of their semiconducting properties. Namely, the enrichment of the outer part of the electrochemically formed passive film with Cr(VI)-species results in a decrease in the density of oxygen vacancies, which act as Pitting initiation sites, and their ‘replacement’ by metal vacancies formed by the electrochemical oxidation of Cr(III) to Cr(VI). In this configuration, the outer Cr(VI)-rich oxide layer behaves as cation selective, which results in the increased Pitting Corrosion Resistance of the film. The simple electrochemical passivation technique discussed in the paper can be efficiently used to form highly Pitting resistant passive films on 316LVM-built medical implant devices of any geometry.
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improvement of Pitting Corrosion Resistance of a biomedical grade 316lvm stainless steel by electrochemical modification of the passive film semiconducting properties
Electrochemistry Communications, 2007Co-Authors: Abdullah Shahryari, Sasha OmanovicAbstract:Abstract In the present paper we show that a significant improvement in Pitting Corrosion Resistance of a biomedical grade stainless steel, 316LVM, can be achieved by the formation of a surface passive oxide film under cyclic potentiodyanamic polarization (passivation) conditions. A complete absence of Pitting in physiological simulating solutions was demonstrated, while the electrochemically formed passive film maintained its very high Pitting Resistance even at higher chloride concentrations in the bulk solution. The improvement in the film’s Pitting Corrosion Resistance was correlated with its semiconducting properties.
Ziying Zhang - One of the best experts on this subject based on the ideXlab platform.
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microstructure evolution and Pitting Corrosion behavior of uns s32750 super duplex stainless steel welds after short time heat treatment
Corrosion Science, 2017Co-Authors: Ziying Zhang, Hui Zhao, Huizhen Zhang, Jiarui JinAbstract:Abstract The effects of short-time heat treatment at different temperatures on the microstructure evolution and Pitting Corrosion behavior of UNS S32750 super duplex stainless steel welds were investigated. The results demonstrated that the ferrite phase in the as-welded heat-affected zone overwhelmed the austenite phase in content and was easily attacked by Pitting Corrosion. After short-time heat treatment, the excessive ferritization in the heat-affected zone was significantly alleviated. The highest Pitting Corrosion Resistance of the welds was obtained at 1080 °C.
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effect of prolonged thermal cycles on the Pitting Corrosion Resistance of a newly developed ldx 2404 lean duplex stainless steel
Corrosion Science, 2016Co-Authors: Ziying Zhang, Huizhen Zhang, Hui ZhaoAbstract:Abstract The effect of aging temperature on the microstructure and Pitting Corrosion behavior of a newly developed LDX 2404 lean duplex stainless steel is investigated. The results show that variations of aging temperature affect the Pitting Corrosion Resistance of LDX 2404 due to the formation of precipitates. The preferential zones for the initiation of pits transform from the austenite phase for the as-annealed specimens to the chromium-depleted zones for the aged ones. The Pitting Corrosion Resistance of the aged specimens drops firstly and then increases again with the increase of aging temperature, and the lowest Corrosion Resistance is exhibited at 800 °C.
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microstructural evolution and Pitting Resistance of annealed lean duplex stainless steel uns s32304
Nuclear Engineering and Design, 2012Co-Authors: Yiming Jiang, Dong Han, Ziying Zhang, Chong ShiAbstract:Abstract The effect of annealing temperature in the range from 1000 to 1200 °C on the Pitting Corrosion behavior of duplex stainless steel UNS S32304 was investigated by the potentiodynamic polarization and potentiostatic critical Pitting temperature techniques. The microstructural evolution and pit morphologies were studied using a scanning electron microscopy with energy dispersive X-ray spectroscopy. The results demonstrated that the nucleation of metastable pits transformed from austenite phase to ferrite phase with the increasing annealing temperature. As the annealing temperature increased, the Pitting Corrosion Resistance firstly increased and then decreased. The highest Pitting Corrosion Resistance was obtained at 1080 °C with the highest critical Pitting temperature value and Pitting nucleation Resistance. The results could be well explained by the microstructural evolution of ferrite and austenite phases induced by annealing treatment.
Joonoh Moon - One of the best experts on this subject based on the ideXlab platform.
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effect of mo and cr additions on the microstructure mechanical properties and Pitting Corrosion Resistance of austenitic fe 30mn 10 5al 1 1c lightweight steels
Journal of Alloys and Compounds, 2019Co-Authors: Joonoh Moon, Taeho Lee, Seongjun Park, Jae Hoon Jang, Changhoon Lee, Heung Nam Han, Hyunuk HongAbstract:Abstract Five Fe-30 wt%Mn-10.5 wt%Al-1.1 wt%C steels containing different Mo and Cr contents were prepared to investigate the effect of Mo and Cr addition on the microstructure, mechanical properties and Pitting Corrosion Resistance of austenitic lightweight steels. The microstructures of all samples after solution treatment at 1050 °C consisted of austenite and κ-carbide, while DO3 ordered phases were additionally formed in samples containing 3 wt%Mo-3wt%Cr or 5 wt%Cr. The results of Nanoindentation tests indicated that the intrinsic strength of the austenite matrix decreased with the addition of Mo and Cr due to the suppression of κ-carbide precipitation and then the strength of the DO3 phase is equal or higher as compared to the austenite matrix. The tensile tests also showed that the yield strength decreased when 3 wt%Mo or 3 wt%Cr was added due to the suppression of κ-carbide precipitation, whereas it increased with further additions of Mo and Cr in both cases due to the formation of a DO3 ordered phases and grain refinement. Electrochemical tests showed that the Resistance to Pitting Corrosion was improved by the addition of Mo and Cr due to the formation of a protective passive film; however, the excessive additions of Mo or Cr adversely deteriorated the Resistance to Pitting Corrosion as the DO3 ordered phase which acted as pit initiation sites.
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investigation of the localized Corrosion and passive behavior of type 304 stainless steels with 0 2 1 8 wt b
Materials, 2018Co-Authors: Jae Hoon Jang, Taeho Lee, Joonoh Moon, Changhoon Lee, Chihyoung Won, Changgeun LeeAbstract:The Pitting Corrosion Resistance and passive behavior of type 304 borated stainless steels (Febalance–18Cr–12Ni–1.5Mn–(0.19, 0.78, and 1.76 wt %)B) manufactured through conventional ingot metallurgy were investigated. The alloys were composed of an austenitic matrix and Cr2B phase, and the volume fraction of Cr2B increased from 1.68 to 22.66 vol % as the B content increased from 0.19 to 1.76 wt %. Potentiodynamic polarization tests measured in aqueous NaCl solutions revealed that the Pitting Corrosion Resistance was reduced as the B content increased and the pits were initiated at the matrix adjacent to the Cr2B phase. It was found that the reduced Resistance to Pitting Corrosion by B addition was due to the formation of more defective and thinner passive film and increased pit initiation sites in the matrix.
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Investigation of the Localized Corrosion and Passive Behavior of Type 304 Stainless Steels with 0.2–1.8 wt % B
MDPI AG, 2018Co-Authors: Jae Hoon Jang, Taeho Lee, Joonoh Moon, Changhoon Lee, Chihyoung Won, Changgeun LeeAbstract:The Pitting Corrosion Resistance and passive behavior of type 304 borated stainless steels (Febalance–18Cr–12Ni–1.5Mn–(0.19, 0.78, and 1.76 wt %)B) manufactured through conventional ingot metallurgy were investigated. The alloys were composed of an austenitic matrix and Cr2B phase, and the volume fraction of Cr2B increased from 1.68 to 22.66 vol % as the B content increased from 0.19 to 1.76 wt %. Potentiodynamic polarization tests measured in aqueous NaCl solutions revealed that the Pitting Corrosion Resistance was reduced as the B content increased and the pits were initiated at the matrix adjacent to the Cr2B phase. It was found that the reduced Resistance to Pitting Corrosion by B addition was due to the formation of more defective and thinner passive film and increased pit initiation sites in the matrix
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understanding the relation between phase fraction and Pitting Corrosion Resistance of uns s32750 stainless steel
Materials Characterization, 2015Co-Authors: Minho Jang, Taeho Lee, Joonoh MoonAbstract:Abstract The relation among overall Pitting Corrosion Resistance, galvanic Corrosion rate between ferrite and austenite phases, and phase fraction (42–67 vol.% ferrite phase) of UNS S32750 alloy was investigated. The highest Pitting potential was obtained in the sample comprising 56 vol.% ferrite. The measured Resistance against the Pitting Corrosion was closely related to the galvanic Corrosion rate between the two constituent phases rather than the individual Pitting Corrosion equivalent numbers of the two phases. This observation inferred that the Resistance to the stable Pitting Corrosion was determined by the pit growth rate rather than the pit initiation probability.
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interpretation of the relation between ferrite fraction and Pitting Corrosion Resistance of commercial 2205 duplex stainless steel
Corrosion Science, 2014Co-Authors: Minho Jang, Taeho Lee, Joonoh MoonAbstract:Abstract The relation among Pitting Corrosion Resistance, galvanic Corrosion rate and phase fraction (44–63 vol% of ferrite phase) of UNS S32205/S31803 duplex stainless steel was investigated. The highest Pitting potential was observed in the sample comprising 57 vol% of ferrite, and it decreased with increase in the phase imbalance. In the sample with 57 vol% ferrite fraction, the lowest galvanic Corrosion rate between the ferrite and austenite phases was observed. It was found that the Pitting Corrosion Resistance of the alloy samples comprising various ferrite fractions was primarily determined by the galvanic Corrosion Resistance between the two constituent phases.