Strip-shaped chromatic aberration defects on the surface of an electro-galvanized fingerprint-resistant sheet were systematically studied using Thermo-Calc thermodynamic calculations,scanning electron microscope and X...Strip-shaped chromatic aberration defects on the surface of an electro-galvanized fingerprint-resistant sheet were systematically studied using Thermo-Calc thermodynamic calculations,scanning electron microscope and X-ray diffractometer analyses,and rapid heat treatment simulation technology.The formation mechanism of these defects was also analyzed.The results show a strong correlation between the defects and the uneven distribution of the Fe(001)component on the surface of the steel substrate.The relatively high proportion of Fe(001)components on the surface of the steel substrate affects the distribution density of the Zn crystal cells in different orientations during the electrodeposition process,which causes the reflection intensity of the light of the galvanized layer to differ from various visual perspectives,and macroscopic strip-shaped chromatic aberration defects are finally formed.The high proportion of the Fe(001)component on the surface of the steel substrate is mainly related to the following two factors.First,when the strip steel is hot-rolled,the finishing hot-rolling temperature is close to theγ→αphase transition temperature.When the local temperature on the upper surface of the strip steel is low,γ+αtwo-phase rolling easily occurs,and this results in an uneven stress distribution between theγandαphases after the hot-rolling process.This uneven distribution of hot-rolling stress results in the formation of a coarse grain structure in the local area on the surface of the hot-rolled sheet,which strongly affects the subsequent cold rolling and annealing process,and the annealed steel sheet substrate ultimately contains a greater proportion of the Fe(001)component.And second,a fast cooling rate(>10 K/s)during the slow cooling stage in the continuous annealing process inhibits the transformation of the Fe(001)to the Fe(111)component on the surface of the cold-rolled steel sheet,and it is then not possible to effectively eliminate the influence of the unevenly distributed Fe(001)component on the surface of the annealed steel sheet(originating from the uneven hot-rolled microstructure).This uneven distribution of the Fe(001)component on the surface of the annealed steel sheet following the continuous annealing heat treatment has a strong effect on the electrodeposition behavior of the Zn crystal cell in the subsequent electroplating process and the formation of macroscopic strip-shaped chromatic aberration defects on the surface of electro-galvanized fingerprint-resistant sheet.展开更多
In this study,the solidified microstructure and segregation behaviors of the alloying elements and precipitate behaviors of the UNS N10276 alloy in a large-scale electroslag remelting(ESR)ingot were studied.Further,th...In this study,the solidified microstructure and segregation behaviors of the alloying elements and precipitate behaviors of the UNS N10276 alloy in a large-scale electroslag remelting(ESR)ingot were studied.Further,the formation of the solidified microstructure and segregation of ESR were systematically analyzed via thermodynamic calculations.The ESR ingot of the UNS N10276 alloy exhibits a typical dendritic structure.The secondary dendrite spacing at the head of the ingot is clearly larger than that at the bottom of the ingot.The alloying elements(e.g.,Mo,Mn,Si,and C),which are positive segregation elements,segregate to the interdendritic zones during the solidification process.However,Fe,W,and Cr segregate to the dendritic trunk zones,indicating that they are negative segregation elements.Among the alloying elements,Mo segregates the most,especially at the head of the ESR ingot.Majority of the precipitates that precipitate in the interdendritic zones and at grain boundaries belong to large-scale μ and M6C phases,respectively.Mo is the main element of the precipitates.The precipitates at the head of the ESR ingot are more abundant and larger than those at the bottom of the ingot.Hence,to improve the metallurgical quality and hot working properties of the UNS N10276 alloy,the segregation of the Mo element should be minimized,whereas the formation of the precipitates should be reduced as much as possible during the optimization of the composition and production processes.展开更多
The process parameters of pulsed tungsten inert gas(PTIG)have a significant infuence on the forma-tion quality,mechanical properties and corrosion resistance of the weld overlay.The PTIG was utilized to deposit Incone...The process parameters of pulsed tungsten inert gas(PTIG)have a significant infuence on the forma-tion quality,mechanical properties and corrosion resistance of the weld overlay.The PTIG was utilized to deposit Inconel 625 clads with various combinations of the process parameters,which were determined by the central composite design(CCD)method.Based on the experimental results,the relationship between process parameters of PTIG and formation quality of the Inconel 625 clads was established using support vector regression(SVR)with different kernel functions,including polynomial kernel function,radial basis function(RBF)kernel function,and sigmoid kernel function.The results indicate that the kernel functions have a great influence on the prediction of height,width and dilution.The models with RBF kernel function feature the best goodness of fitting and the most accurate against the other SVR models for estimating the height and the dilution.However,the model with polynomial kernel function is superior to the other SVR models for predicting the width.Meanwhile,the prediction performance of the SVR models was compared with the general regression analysis.The results demonstrate that the optimized SVR model is much better than the general regression model in the prediction performance.展开更多
文摘Strip-shaped chromatic aberration defects on the surface of an electro-galvanized fingerprint-resistant sheet were systematically studied using Thermo-Calc thermodynamic calculations,scanning electron microscope and X-ray diffractometer analyses,and rapid heat treatment simulation technology.The formation mechanism of these defects was also analyzed.The results show a strong correlation between the defects and the uneven distribution of the Fe(001)component on the surface of the steel substrate.The relatively high proportion of Fe(001)components on the surface of the steel substrate affects the distribution density of the Zn crystal cells in different orientations during the electrodeposition process,which causes the reflection intensity of the light of the galvanized layer to differ from various visual perspectives,and macroscopic strip-shaped chromatic aberration defects are finally formed.The high proportion of the Fe(001)component on the surface of the steel substrate is mainly related to the following two factors.First,when the strip steel is hot-rolled,the finishing hot-rolling temperature is close to theγ→αphase transition temperature.When the local temperature on the upper surface of the strip steel is low,γ+αtwo-phase rolling easily occurs,and this results in an uneven stress distribution between theγandαphases after the hot-rolling process.This uneven distribution of hot-rolling stress results in the formation of a coarse grain structure in the local area on the surface of the hot-rolled sheet,which strongly affects the subsequent cold rolling and annealing process,and the annealed steel sheet substrate ultimately contains a greater proportion of the Fe(001)component.And second,a fast cooling rate(>10 K/s)during the slow cooling stage in the continuous annealing process inhibits the transformation of the Fe(001)to the Fe(111)component on the surface of the cold-rolled steel sheet,and it is then not possible to effectively eliminate the influence of the unevenly distributed Fe(001)component on the surface of the annealed steel sheet(originating from the uneven hot-rolled microstructure).This uneven distribution of the Fe(001)component on the surface of the annealed steel sheet following the continuous annealing heat treatment has a strong effect on the electrodeposition behavior of the Zn crystal cell in the subsequent electroplating process and the formation of macroscopic strip-shaped chromatic aberration defects on the surface of electro-galvanized fingerprint-resistant sheet.
基金funded by National Science and Technology Major Project( No. 2015ZX06002001-001)
文摘In this study,the solidified microstructure and segregation behaviors of the alloying elements and precipitate behaviors of the UNS N10276 alloy in a large-scale electroslag remelting(ESR)ingot were studied.Further,the formation of the solidified microstructure and segregation of ESR were systematically analyzed via thermodynamic calculations.The ESR ingot of the UNS N10276 alloy exhibits a typical dendritic structure.The secondary dendrite spacing at the head of the ingot is clearly larger than that at the bottom of the ingot.The alloying elements(e.g.,Mo,Mn,Si,and C),which are positive segregation elements,segregate to the interdendritic zones during the solidification process.However,Fe,W,and Cr segregate to the dendritic trunk zones,indicating that they are negative segregation elements.Among the alloying elements,Mo segregates the most,especially at the head of the ESR ingot.Majority of the precipitates that precipitate in the interdendritic zones and at grain boundaries belong to large-scale μ and M6C phases,respectively.Mo is the main element of the precipitates.The precipitates at the head of the ESR ingot are more abundant and larger than those at the bottom of the ingot.Hence,to improve the metallurgical quality and hot working properties of the UNS N10276 alloy,the segregation of the Mo element should be minimized,whereas the formation of the precipitates should be reduced as much as possible during the optimization of the composition and production processes.
基金the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2020JQ-780 and 2017JQ5106)the Open Foundation of Chongqing En-gineering Technology Research Center for Light Alloy Materials and Procesling(No.GCZX202001)the Young Teacher Research Project of Xi'an Shiyou Uni-versity(No.0104-134010025)。
文摘The process parameters of pulsed tungsten inert gas(PTIG)have a significant infuence on the forma-tion quality,mechanical properties and corrosion resistance of the weld overlay.The PTIG was utilized to deposit Inconel 625 clads with various combinations of the process parameters,which were determined by the central composite design(CCD)method.Based on the experimental results,the relationship between process parameters of PTIG and formation quality of the Inconel 625 clads was established using support vector regression(SVR)with different kernel functions,including polynomial kernel function,radial basis function(RBF)kernel function,and sigmoid kernel function.The results indicate that the kernel functions have a great influence on the prediction of height,width and dilution.The models with RBF kernel function feature the best goodness of fitting and the most accurate against the other SVR models for estimating the height and the dilution.However,the model with polynomial kernel function is superior to the other SVR models for predicting the width.Meanwhile,the prediction performance of the SVR models was compared with the general regression analysis.The results demonstrate that the optimized SVR model is much better than the general regression model in the prediction performance.
