On-line dissolution of solid metal sample can be carried out by electrolysis under the control of flow injection analyzer(FIA),and the dissolved sample can be transferred to atomic spectrometer for the direct analysis...On-line dissolution of solid metal sample can be carried out by electrolysis under the control of flow injection analyzer(FIA),and the dissolved sample can be transferred to atomic spectrometer for the direct analysis.The hyphenated technique of FIA on-line electrolytic dissolution of alloy and atomic absorption spectrometer(AAS)detection is developed.The research is focused on the effects of electrolyte composition and electrolysis parameters on the sample dissolving,as well as the quantitative analysis of Cu in Al alloy samples.展开更多
Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-t...Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-thin hot strip of low carbon steel produced by CSP(Compact Strip Production) technique was investigated. The value of each strengthening mechanism andits contribution percentage to yield strength were achieved. The results show that refinementstrengthening is the predominant strengthening mode; precipitation strengthening and dislocationstrengthening are second to it, their contributions to yield strength are almost equal.展开更多
The effect of boron on hot strips of low carbon steel produced by compact strip production （CSP） to reduce the strength to a certain degree was investigated, which is quite different from that of high-strength low a...The effect of boron on hot strips of low carbon steel produced by compact strip production （CSP） to reduce the strength to a certain degree was investigated, which is quite different from that of high-strength low alloy steel. The mechanical properties and microstructural evolution of the hot strip were studied using optical microscopy and tensile tests. By means of an electrolytic dissolution technique and Thermo-Cal calculation, the precipitates containing boron were analyzed and detected. From the electron backscattered diffraction analysis, it can be deciphered whether the microstructure has recrystallized or not. Furthermore, the effect of boron segregation on the recrystallization or non-recrystallization conditions can be distinguished. The segregation behavior of boron was investigated in boron-containing steel. The nonequilibrium segregation of boron during processing was discussed on the basis of the forming complexes with vacancies that migrate to the boundaries prior to annihilation, which was confirmed by the subsequent cold rolling with annealing experiments.展开更多
Via material erosion in wire electrical discharge machining(WEDM),recast layers form on the surfaces of workpiece.In addition,ultra fine Wire-EDM can be usually cut once.To reduce the thickness of the recast layer as ...Via material erosion in wire electrical discharge machining(WEDM),recast layers form on the surfaces of workpiece.In addition,ultra fine Wire-EDM can be usually cut once.To reduce the thickness of the recast layer as much as possible,the wire electrical discharge-electrochemical machining(WEDCM)method was proposed,which is based on the micro conductivity of the dielectric and microelectrolytic characteristics by adjusting the no-load rate of the pulse in the machining process.Furthermore,a state discrimination and servo control system based on discharge current was designed.The experiment results of different no-load rates show that the electrolytic effects increase as the no-load rate increases,and the main machining process is spark discharge erosion with a no-load rate in the range of 10%to 80%.At 90%no-load rate,the amount of recast layer formation in the forward direction of the wire electrode is almost the same as that of electrolytic dissolution,and it can be practically processed without a recast layer.Compared with10%no-load rate,the kerf width only increases by 7.5%.展开更多
文摘On-line dissolution of solid metal sample can be carried out by electrolysis under the control of flow injection analyzer(FIA),and the dissolved sample can be transferred to atomic spectrometer for the direct analysis.The hyphenated technique of FIA on-line electrolytic dissolution of alloy and atomic absorption spectrometer(AAS)detection is developed.The research is focused on the effects of electrolyte composition and electrolysis parameters on the sample dissolving,as well as the quantitative analysis of Cu in Al alloy samples.
基金This work was financially supported by the state foundation for key projects: Fundamental Research on New Generation of Steels (No: G1998061500).
文摘Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-thin hot strip of low carbon steel produced by CSP(Compact Strip Production) technique was investigated. The value of each strengthening mechanism andits contribution percentage to yield strength were achieved. The results show that refinementstrengthening is the predominant strengthening mode; precipitation strengthening and dislocationstrengthening are second to it, their contributions to yield strength are almost equal.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50774110)Fok Ying Tong Edu-cation Foundation (No.104017).
文摘The effect of boron on hot strips of low carbon steel produced by compact strip production （CSP） to reduce the strength to a certain degree was investigated, which is quite different from that of high-strength low alloy steel. The mechanical properties and microstructural evolution of the hot strip were studied using optical microscopy and tensile tests. By means of an electrolytic dissolution technique and Thermo-Cal calculation, the precipitates containing boron were analyzed and detected. From the electron backscattered diffraction analysis, it can be deciphered whether the microstructure has recrystallized or not. Furthermore, the effect of boron segregation on the recrystallization or non-recrystallization conditions can be distinguished. The segregation behavior of boron was investigated in boron-containing steel. The nonequilibrium segregation of boron during processing was discussed on the basis of the forming complexes with vacancies that migrate to the boundaries prior to annihilation, which was confirmed by the subsequent cold rolling with annealing experiments.
基金the National Natural Science Foundation of China(Nos.51575271 and 51975290)。
文摘Via material erosion in wire electrical discharge machining(WEDM),recast layers form on the surfaces of workpiece.In addition,ultra fine Wire-EDM can be usually cut once.To reduce the thickness of the recast layer as much as possible,the wire electrical discharge-electrochemical machining(WEDCM)method was proposed,which is based on the micro conductivity of the dielectric and microelectrolytic characteristics by adjusting the no-load rate of the pulse in the machining process.Furthermore,a state discrimination and servo control system based on discharge current was designed.The experiment results of different no-load rates show that the electrolytic effects increase as the no-load rate increases,and the main machining process is spark discharge erosion with a no-load rate in the range of 10%to 80%.At 90%no-load rate,the amount of recast layer formation in the forward direction of the wire electrode is almost the same as that of electrolytic dissolution,and it can be practically processed without a recast layer.Compared with10%no-load rate,the kerf width only increases by 7.5%.
