The Experts below are selected from a list of 8838 Experts worldwide ranked by ideXlab platform
Woeiren Wang - One of the best experts on this subject based on the ideXlab platform.
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oxidation resistant silane coating for hot dip galvanized hot stamping steel
Corrosion Science, 2020Co-Authors: Jun-kai Chang, Weijen Cheng, Ihsuang Lo, Chao-sung Lin, Woeiren WangAbstract:Abstract A silane coating was developed for hot-dip galvanized (HDG) steel via a sol-gel roll coating method and its oxidation resistance during Austenitization was detailed. The HDG steel with silane coating retains metallic appearance after 900 °C Austenitization for 5 min. Moreover, the silane coating preserves more Zn in the alloy layer, conferring better corrosion resistance. Liquid metal embrittlement is absent when a thinner Zn coating (∼ 7 μm) is applied, yet imparts cathodic protection to the austenitized silane-coated HDG steel with a cosmetic coating. The silane coating markedly inhibits oxidation and confers enhanced corrosion resistance for hot-stamped HDG steel parts.
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oxidation and corrosion behavior of commercial 5 wt al zn coated steel during Austenitization heat treatment
Surface & Coatings Technology, 2018Co-Authors: Jun-kai Chang, Chao-sung Lin, Woeiren WangAbstract:Abstract A commercial 5 wt% Al-Zn coated steel was employed to detail the microstructural evolution, oxidation, and the related corrosion behavior changes during the Austenitization heat treatment. During the early stages of Austenitization, Fe2Al5Znx phase forms between the coating and the steel substrate. With continued Austenitization, the inner part of the coating transforms to the Γ-Fe3Zn10 phase and the outer part of the coating to the FeAl phase, accompanying with the formation of a thin surface oxide layer mainly composed of Al2O3 with minor ZnO. Subsequently, the coating transforms to the Γ-Fe3Zn10 phase and α-Fe(Zn), and finally to the single α-Fe(Zn) phase. The Al in the coating is distributed mainly on the surface of the alloy layer and suppresses the oxidation of the alloy layer. The Austenitization treatment enriches the coating with Fe, which, in turn, ennobles the corrosion potential and reduces the corrosion current density of the coating. Conversely, the potential difference between the coating and the steel substrate is reduced after Austenitization.
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microstructural evaluation and property change of 5 wt pct al zn coating on press hardening steel during Austenitization
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2018Co-Authors: Jun-kai Chang, Woeiren Wang, Chao-sung Lin, Weijen ChengAbstract:Microstructural evolution of a 5 wt pct Al-Zn coating on press hardening steel was studied in comparison to hot-dip galvanized (GI) and galvannealed (GA) coatings. The results show that the presence of 5 wt pct Al effectively suppresses oxidation during Austenitization; meanwhile, the presence of Fe resulting from galvannealing accelerates oxidation. Alloying with Al or Fe in the coating prior to Austenitization reduces the susceptibility to liquid metal embrittlement (LME). The presence of Al in the as-coated Zn coating enhances the corrosion resistance in HCl solution and reduces the cathodic kinetics in NaCl solution. However, for sacrificial protection, the austenitized GI steel outperforms the other austenitized-coated steels. Nevertheless, the 5 wt pct Al-Zn coating exhibits better overall performance including high-temperature oxidation resistance, less LME susceptibility, and cathodic protection.
Jun-kai Chang - One of the best experts on this subject based on the ideXlab platform.
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oxidation resistant silane coating for hot dip galvanized hot stamping steel
Corrosion Science, 2020Co-Authors: Jun-kai Chang, Weijen Cheng, Ihsuang Lo, Chao-sung Lin, Woeiren WangAbstract:Abstract A silane coating was developed for hot-dip galvanized (HDG) steel via a sol-gel roll coating method and its oxidation resistance during Austenitization was detailed. The HDG steel with silane coating retains metallic appearance after 900 °C Austenitization for 5 min. Moreover, the silane coating preserves more Zn in the alloy layer, conferring better corrosion resistance. Liquid metal embrittlement is absent when a thinner Zn coating (∼ 7 μm) is applied, yet imparts cathodic protection to the austenitized silane-coated HDG steel with a cosmetic coating. The silane coating markedly inhibits oxidation and confers enhanced corrosion resistance for hot-stamped HDG steel parts.
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oxidation and corrosion behavior of commercial 5 wt al zn coated steel during Austenitization heat treatment
Surface & Coatings Technology, 2018Co-Authors: Jun-kai Chang, Chao-sung Lin, Woeiren WangAbstract:Abstract A commercial 5 wt% Al-Zn coated steel was employed to detail the microstructural evolution, oxidation, and the related corrosion behavior changes during the Austenitization heat treatment. During the early stages of Austenitization, Fe2Al5Znx phase forms between the coating and the steel substrate. With continued Austenitization, the inner part of the coating transforms to the Γ-Fe3Zn10 phase and the outer part of the coating to the FeAl phase, accompanying with the formation of a thin surface oxide layer mainly composed of Al2O3 with minor ZnO. Subsequently, the coating transforms to the Γ-Fe3Zn10 phase and α-Fe(Zn), and finally to the single α-Fe(Zn) phase. The Al in the coating is distributed mainly on the surface of the alloy layer and suppresses the oxidation of the alloy layer. The Austenitization treatment enriches the coating with Fe, which, in turn, ennobles the corrosion potential and reduces the corrosion current density of the coating. Conversely, the potential difference between the coating and the steel substrate is reduced after Austenitization.
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microstructural evaluation and property change of 5 wt pct al zn coating on press hardening steel during Austenitization
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2018Co-Authors: Jun-kai Chang, Woeiren Wang, Chao-sung Lin, Weijen ChengAbstract:Microstructural evolution of a 5 wt pct Al-Zn coating on press hardening steel was studied in comparison to hot-dip galvanized (GI) and galvannealed (GA) coatings. The results show that the presence of 5 wt pct Al effectively suppresses oxidation during Austenitization; meanwhile, the presence of Fe resulting from galvannealing accelerates oxidation. Alloying with Al or Fe in the coating prior to Austenitization reduces the susceptibility to liquid metal embrittlement (LME). The presence of Al in the as-coated Zn coating enhances the corrosion resistance in HCl solution and reduces the cathodic kinetics in NaCl solution. However, for sacrificial protection, the austenitized GI steel outperforms the other austenitized-coated steels. Nevertheless, the 5 wt pct Al-Zn coating exhibits better overall performance including high-temperature oxidation resistance, less LME susceptibility, and cathodic protection.
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Microstructural Evolution of 11Al-3Mg-Zn Ternary Alloy-Coated Steels During Austenitization Heat Treatment
Metallurgical and Materials Transactions A, 2017Co-Authors: Jun-kai Chang, Chao-sung LinAbstract:This study details the microstructural evolution of a commercial hot-dip 11Al-3Mg-Zn-coated steel during Austenitization. After 5 minutes of Austenitization at 1173 K (900 °C), the ternary alloy coating transformed to consist of a nearly pure Zn as the major layer, a Fe-Al alloy layer at the interface, and a thin oxide overlay. The Fe-Al alloy layer effectively acted as the inhibition layer to prevent Fe from diffusing and reacting with Zn, which in turn retained the molten Zn layer and the integrity of the surface oxide layer. Moreover, the potential difference between the 11Al-3Mg-Zn coating and the steel substrate remained similar after Austenitization, signifying the resulting coating kept its sacrificial protection capability.
Chao-sung Lin - One of the best experts on this subject based on the ideXlab platform.
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oxidation resistant silane coating for hot dip galvanized hot stamping steel
Corrosion Science, 2020Co-Authors: Jun-kai Chang, Weijen Cheng, Ihsuang Lo, Chao-sung Lin, Woeiren WangAbstract:Abstract A silane coating was developed for hot-dip galvanized (HDG) steel via a sol-gel roll coating method and its oxidation resistance during Austenitization was detailed. The HDG steel with silane coating retains metallic appearance after 900 °C Austenitization for 5 min. Moreover, the silane coating preserves more Zn in the alloy layer, conferring better corrosion resistance. Liquid metal embrittlement is absent when a thinner Zn coating (∼ 7 μm) is applied, yet imparts cathodic protection to the austenitized silane-coated HDG steel with a cosmetic coating. The silane coating markedly inhibits oxidation and confers enhanced corrosion resistance for hot-stamped HDG steel parts.
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oxidation and corrosion behavior of commercial 5 wt al zn coated steel during Austenitization heat treatment
Surface & Coatings Technology, 2018Co-Authors: Jun-kai Chang, Chao-sung Lin, Woeiren WangAbstract:Abstract A commercial 5 wt% Al-Zn coated steel was employed to detail the microstructural evolution, oxidation, and the related corrosion behavior changes during the Austenitization heat treatment. During the early stages of Austenitization, Fe2Al5Znx phase forms between the coating and the steel substrate. With continued Austenitization, the inner part of the coating transforms to the Γ-Fe3Zn10 phase and the outer part of the coating to the FeAl phase, accompanying with the formation of a thin surface oxide layer mainly composed of Al2O3 with minor ZnO. Subsequently, the coating transforms to the Γ-Fe3Zn10 phase and α-Fe(Zn), and finally to the single α-Fe(Zn) phase. The Al in the coating is distributed mainly on the surface of the alloy layer and suppresses the oxidation of the alloy layer. The Austenitization treatment enriches the coating with Fe, which, in turn, ennobles the corrosion potential and reduces the corrosion current density of the coating. Conversely, the potential difference between the coating and the steel substrate is reduced after Austenitization.
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microstructural evaluation and property change of 5 wt pct al zn coating on press hardening steel during Austenitization
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2018Co-Authors: Jun-kai Chang, Woeiren Wang, Chao-sung Lin, Weijen ChengAbstract:Microstructural evolution of a 5 wt pct Al-Zn coating on press hardening steel was studied in comparison to hot-dip galvanized (GI) and galvannealed (GA) coatings. The results show that the presence of 5 wt pct Al effectively suppresses oxidation during Austenitization; meanwhile, the presence of Fe resulting from galvannealing accelerates oxidation. Alloying with Al or Fe in the coating prior to Austenitization reduces the susceptibility to liquid metal embrittlement (LME). The presence of Al in the as-coated Zn coating enhances the corrosion resistance in HCl solution and reduces the cathodic kinetics in NaCl solution. However, for sacrificial protection, the austenitized GI steel outperforms the other austenitized-coated steels. Nevertheless, the 5 wt pct Al-Zn coating exhibits better overall performance including high-temperature oxidation resistance, less LME susceptibility, and cathodic protection.
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Microstructural Evolution of 11Al-3Mg-Zn Ternary Alloy-Coated Steels During Austenitization Heat Treatment
Metallurgical and Materials Transactions A, 2017Co-Authors: Jun-kai Chang, Chao-sung LinAbstract:This study details the microstructural evolution of a commercial hot-dip 11Al-3Mg-Zn-coated steel during Austenitization. After 5 minutes of Austenitization at 1173 K (900 °C), the ternary alloy coating transformed to consist of a nearly pure Zn as the major layer, a Fe-Al alloy layer at the interface, and a thin oxide overlay. The Fe-Al alloy layer effectively acted as the inhibition layer to prevent Fe from diffusing and reacting with Zn, which in turn retained the molten Zn layer and the integrity of the surface oxide layer. Moreover, the potential difference between the 11Al-3Mg-Zn coating and the steel substrate remained similar after Austenitization, signifying the resulting coating kept its sacrificial protection capability.
Marcel A. J. Somers - One of the best experts on this subject based on the ideXlab platform.
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Kinetics analysis of two-stage Austenitization in supermartensitic stainless steel
Materials & Design, 2017Co-Authors: Frank Niessen, Matteo Villa, John Hald, Marcel A. J. SomersAbstract:Abstract The martensite-to-austenite transformation in X4CrNiMo16-5-1 supermartensitic stainless steel was followed in-situ during isochronal heating at 2, 6 and 18 K min− 1 applying energy-dispersive synchrotron X-ray diffraction at the BESSY II facility. Austenitization occurred in two stages, separated by a temperature region in which the transformation was strongly decelerated. The region of limited transformation was more concise and occurred at higher austenite phase fractions and temperatures for higher heating rates. The two-step kinetics was reproduced by kinetics modeling in DICTRA. The model indicates that the Austenitization kinetics is governed by Ni-diffusion and that slow transformation kinetics separating the two stages is caused by soft impingement in the martensite phase. Increasing the lath width in the kinetics model had a similar effect on the Austenitization kinetics as increasing the heating-rate.
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In Situ Techniques for the Investigation of the Kinetics of Austenitization of Supermartensitic Stainless Steel
Materials Science Forum, 2016Co-Authors: Frank Niessen, Matteo Villa, John Hald, Daniel Apel, Olaf Keßler, Michael Reich, Marcel A. J. SomersAbstract:The Austenitization and inter-critical annealing of X4CrNiMo16-5-1 (1.4418) supermartensitic stainless steel were investigated in-situ with synchrotron X-ray diffraction (XRD), dilatometry and differential scanning calorimetry (DSC) under isochronal heating conditions. Austenitization occurred in two stages: the Austenitization started at approx. 600 °C, decelerated at approx. 700 °C at 60 to 75 v.% of transformed austenite, and first resumed after heating for approx. 100 °C. This plateau in the transformation curve was more dominant for faster heating rates. Inter-critical annealing at 675 and 700 °C revealed, that austenite can to a certain extent be stabilized to room-temperature. There was good agreement for the transformation curves yielded by dilatometry and XRD. Some deviation occurred due to the different applied heating principles, different temperature monitoring and the impact of surface martensite formation on the XRD measurement. The applicable temperature range for DSC as well as the close proximity of the Ac1- and the Curie-temperature limited the usage of the technique in the present case.
S. R. Prabhakar - One of the best experts on this subject based on the ideXlab platform.
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Impact Properties of Copper-Alloyed and Nickel-Copper Alloyed ADI
Journal of Materials Engineering and Performance, 2007Co-Authors: Uma Batra, S. R. PrabhakarAbstract:The influence of Austenitization and austempering parameters on the impact properties of copper-alloyed and nickel-copper-alloyed austempered ductile irons (ADIs) has been studied. The Austenitization temperature of 850 and 900 °C have been used in the present study for which austempering time periods of 120 and 60 min were optimized in an earlier work. The austempering process was carried out for 60 min for three austempering temperatures of 270, 330, and 380 °C to study the effect of austempering temperature. The influence of the austempering time on impact properties has been studied for austempering temperature of 330 °C for time periods of 30-150 min. The variation in impact strength with the Austenitization and austempering parameters has been correlated to the morphology, size and amount of austenite and bainitic ferrite in the austempered structure. The fracture surface of ADI failed under impact has been studied using SEM.
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Mathematical model for Austenitization kinetics of ductile iron
Journal of Materials Engineering and Performance, 2005Co-Authors: Uma Batra, S. R. PrabhakarAbstract:A mathematical model was developed in the current study to understand the progress of Austenitization process in ductile irons. The Austenitization time required to produce homogeneous austenite in a two-phase region of austenite and graphite has been estimated in terms of (a) time required for transformation of matrix to austenite and (b) time required for dissolution of graphite in austenite to attain uniform carbon content, which remains in equilibrium with graphite. The time required been related to the structural parameters of cast ductile iron-like radius of graphite nodule, radius of austenite cell, volume fraction of graphite, volume fraction of ferrite in cast matrix, and diffusion constant. The model was used to determine the minimum Austenitization time required to achieve homogeneous austenite in three commercial ductile irons when austenitized at a temperature of 900 °C. The results were compared with those obtained. The uniformity of the carbon content in austenite of ductile iron was verified indirectly by measuring microhardness.
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effect of Austenitization on austempering of copper alloyed ductile iron
Journal of Materials Engineering and Performance, 2003Co-Authors: Uma Batra, S. R. PrabhakarAbstract:A ductile iron containing 0.6% copper as the main alloying element was austempered at a fixed austempering temperature of 330 °C for a fixed austempering time of 60 min after Austenitization at 850 °C for different Austenitization periods of 60, 90, and 120 min. The austempering process was repeated after changing Austenitization temperature to 900 °C. The effect of Austenitization temperature and time was studied on the carbon content and its distribution in the austenite after Austenitization. The effect of Austenitization parameters was also studied on austempered microstructure, structural parameters like volume fraction of austenite, Xγ, carbon content Cγ, and XγCγ, and bainitic ferrite needle size, dα after austempering. The average carbon content of austenite increases linearly with Austenitization time and reaches a saturation level. Higher Austenitization temperature results in higher carbon content of austenite. As regards the austempered structure, the lowering Austenitization temperature causes significant refinement and more uniform distribution of austempered structure, and a decrease in the volume fraction of retained austenite.
