The deformation process of the microstructure in 2205 duplex stainless steel(DSS)under thermo-mechanical coupling at 250℃was investigated using digital image correlation(DIC).A thermal tension test of duplex stainles...The deformation process of the microstructure in 2205 duplex stainless steel(DSS)under thermo-mechanical coupling at 250℃was investigated using digital image correlation(DIC).A thermal tension test of duplex stainless steel(2205DSS)with a banded structure was carded out to observe the initial deformation of the microstructure.It was found that inhomogeneous strain fields occurred primarily in austenite.The maximum normal strain in austenite was almost pos-itive,while that in ferrite was almost negative.In addition,a thermal cyclic-loading test was conducted,and the strain field was characterized by e11.Strain heterogeneities were induced after 400 cycles,which spread within the austenite and at the phase boundaries with the load increasing.The high tensile-strain regions were always located adjacent to regions of intense compressive strain.Based on the strain matrix sum vs.cycle number,we found that hardening occurred in the early cycles followed by softening.展开更多
提出了电感耦合等离子体原子发射光谱法(ICP-AES)测定核级316不锈钢中痕量铈的方法。取0.100 0 g样品于烧杯中,加入15 m L现配体积比为1∶3∶4的硝酸-盐酸-水混酸溶液,置于150℃电热板上消解30 min,完全溶解后加入5 m L 30%(质量分数)...提出了电感耦合等离子体原子发射光谱法(ICP-AES)测定核级316不锈钢中痕量铈的方法。取0.100 0 g样品于烧杯中,加入15 m L现配体积比为1∶3∶4的硝酸-盐酸-水混酸溶液,置于150℃电热板上消解30 min,完全溶解后加入5 m L 30%(质量分数)过氧化氢溶液,恒温3 min后取下冷却至室温,用水定容至100 m L。设置仪器射频功率为1 150 W,雾化气流量为0.45 L·min^(-1),测量铈元素在404.076 nm分析谱线处的响应强度,基质匹配法定量。结果表明:铈的质量浓度在100 mg·L^(-1)以内与对应的响应强度呈线性关系,检出限(3s)为0.000 4%。4个样品精密度试验所得测定值的相对标准偏差(n=10)均小于5.0%。按照标准加入法进行回收试验,回收率为95.5%~103%;采用GH56(屑样)铁镍基标准物质进行准确度验证,测定值与认定值基本一致。展开更多
An innovative application of laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） technique in illustrating elemental distributions on stainless steel sheets was presented. The technique proved to...An innovative application of laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） technique in illustrating elemental distributions on stainless steel sheets was presented. The technique proved to be a systematic and accurate ap- proach in producing visual images or maps of elemental distributions at cross-sectional surface of a stainless steel sheet. Two stain- less steel sheets served as research objects： 3 mm×l 300 mm hot-rolled stainless steel plate and 1 mm×l 260 mm cold-rolled plate. The cross-sectional surfaces of the two samples at 1/4 position along the width direction were scanned （raster area -44 mm2 and 11 mm2） with a focused laser beam （wavelength 213 nm, diameter of laser crater 100 μm, and laser power 1.6 mJ） in a laser abla- tion chamber. The laser ablation system was coupled to a quadrupole ICP-MS, which made the detection of ion intensities of 27A1＋, 44Ca＋, 47Ti-, 55Mn＋ and 56Fe＋ within an area of interest possible. One-dimensional （ID） content line distribution maps and two- dimensional （2D） contour maps for specific positions or areas were plotted to indicate the element distribution of a target area with high accuracy. Statistic method was used to analyze the acquired data by calculating median contents, maximum segregation, sta- tistic segregation and content-frequency distribution.展开更多
Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive mod...Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive model and continuum damage mechanics theory, the damage-coupled multi-axial time-dependent constitutive model and fatigue failure model were proposed. In the model, the evolution equation of damage was introduced in and the time-dependent effects, e.g. holding time, loading rate, were taken into account. The model was applied to the simulation of whole-life cyclic deformation behaviors and prediction of LCF life for SS304 stainless steel in multiaxial time-dependent low cycle fatigue tests. It is shown that the simulated results agree well with experimental ones.展开更多
Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO-SiO_(2) oxide during isothermal heating at ...Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO-SiO_(2) oxide during isothermal heating at 1473 K(1200℃)for 1,3,5,and 10 h and at 1173,1273,1373,1473,and 1573 K(900,1000,1100,1200,and 1300℃)for 3 h.Compositional variations in the 316L stainless steel and the composite MnO-SiO_(2) oxide in the vicinity of the steel-oxide interface in each diffusion couple specimen were determined.Before and after isothermal heating,thermodynamic equilibria between the oxide and steel at the interface were estimated in accordance with the calculation of the Gibbs free energy change in the interfacial steel-oxide reactions.The diffusion coefficients of Mn,Cr,and Si in 316L stainless steel under different experimental conditions were quantitatively acquired.The results showed that solid-state interfacial reactions occurred between the Cr in the 316L stainless steel and composite MnO-SiO_(2) oxide during isothermal heating,which resulted in the depletion of Cr and accumulation of Si and Mn in the steel in the vicinity of the steel-oxide interface.The widths of the Crdepleted zone,Mn-accumulated zone and Si-accumulated zone all showed increasing trends with increasing isothermal heating temperature and time.The average values of the diffusion coefficients of Mn,Cr,and Si in the steel at 1473 K(1200℃)were 1.21×10^(^(-14))±2.96×10^(-15),1.69×10^(-14)±2.54×10^(-15),and 1.00×10^(-14)±1.96×10^(-15) m^(2)s^(-1),respectively,and they continued to increase with increasing isothermal heating temperature.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11472187 and 11602166)the National Basic Research Program of China(Grant No.2014CB046805)the Natural Science Foundation of Tianjin,China(Grant No.16JCYBJC40500)
文摘The deformation process of the microstructure in 2205 duplex stainless steel(DSS)under thermo-mechanical coupling at 250℃was investigated using digital image correlation(DIC).A thermal tension test of duplex stainless steel(2205DSS)with a banded structure was carded out to observe the initial deformation of the microstructure.It was found that inhomogeneous strain fields occurred primarily in austenite.The maximum normal strain in austenite was almost pos-itive,while that in ferrite was almost negative.In addition,a thermal cyclic-loading test was conducted,and the strain field was characterized by e11.Strain heterogeneities were induced after 400 cycles,which spread within the austenite and at the phase boundaries with the load increasing.The high tensile-strain regions were always located adjacent to regions of intense compressive strain.Based on the strain matrix sum vs.cycle number,we found that hardening occurred in the early cycles followed by softening.
文摘提出了电感耦合等离子体原子发射光谱法(ICP-AES)测定核级316不锈钢中痕量铈的方法。取0.100 0 g样品于烧杯中,加入15 m L现配体积比为1∶3∶4的硝酸-盐酸-水混酸溶液,置于150℃电热板上消解30 min,完全溶解后加入5 m L 30%(质量分数)过氧化氢溶液,恒温3 min后取下冷却至室温,用水定容至100 m L。设置仪器射频功率为1 150 W,雾化气流量为0.45 L·min^(-1),测量铈元素在404.076 nm分析谱线处的响应强度,基质匹配法定量。结果表明:铈的质量浓度在100 mg·L^(-1)以内与对应的响应强度呈线性关系,检出限(3s)为0.000 4%。4个样品精密度试验所得测定值的相对标准偏差(n=10)均小于5.0%。按照标准加入法进行回收试验,回收率为95.5%~103%;采用GH56(屑样)铁镍基标准物质进行准确度验证,测定值与认定值基本一致。
基金Sponsored by National Major Instrument and Equipment Development Special Project of China(2011YQ14014710)
文摘An innovative application of laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） technique in illustrating elemental distributions on stainless steel sheets was presented. The technique proved to be a systematic and accurate ap- proach in producing visual images or maps of elemental distributions at cross-sectional surface of a stainless steel sheet. Two stain- less steel sheets served as research objects： 3 mm×l 300 mm hot-rolled stainless steel plate and 1 mm×l 260 mm cold-rolled plate. The cross-sectional surfaces of the two samples at 1/4 position along the width direction were scanned （raster area -44 mm2 and 11 mm2） with a focused laser beam （wavelength 213 nm, diameter of laser crater 100 μm, and laser power 1.6 mJ） in a laser abla- tion chamber. The laser ablation system was coupled to a quadrupole ICP-MS, which made the detection of ion intensities of 27A1＋, 44Ca＋, 47Ti-, 55Mn＋ and 56Fe＋ within an area of interest possible. One-dimensional （ID） content line distribution maps and two- dimensional （2D） contour maps for specific positions or areas were plotted to indicate the element distribution of a target area with high accuracy. Statistic method was used to analyze the acquired data by calculating median contents, maximum segregation, sta- tistic segregation and content-frequency distribution.
基金supported by the Fundamental Research Funds for the Central Universities (No.SWJTU09ZT35)National Science Fund for Distinguished Young Scholars of China (No.11025210)
文摘Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive model and continuum damage mechanics theory, the damage-coupled multi-axial time-dependent constitutive model and fatigue failure model were proposed. In the model, the evolution equation of damage was introduced in and the time-dependent effects, e.g. holding time, loading rate, were taken into account. The model was applied to the simulation of whole-life cyclic deformation behaviors and prediction of LCF life for SS304 stainless steel in multiaxial time-dependent low cycle fatigue tests. It is shown that the simulated results agree well with experimental ones.
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A20113 and 52074198)also supported by the Project for Technology Talents ServinggEnterprises of Hubei Province(Grant No.KJRQ2023000073).
文摘Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO-SiO_(2) oxide during isothermal heating at 1473 K(1200℃)for 1,3,5,and 10 h and at 1173,1273,1373,1473,and 1573 K(900,1000,1100,1200,and 1300℃)for 3 h.Compositional variations in the 316L stainless steel and the composite MnO-SiO_(2) oxide in the vicinity of the steel-oxide interface in each diffusion couple specimen were determined.Before and after isothermal heating,thermodynamic equilibria between the oxide and steel at the interface were estimated in accordance with the calculation of the Gibbs free energy change in the interfacial steel-oxide reactions.The diffusion coefficients of Mn,Cr,and Si in 316L stainless steel under different experimental conditions were quantitatively acquired.The results showed that solid-state interfacial reactions occurred between the Cr in the 316L stainless steel and composite MnO-SiO_(2) oxide during isothermal heating,which resulted in the depletion of Cr and accumulation of Si and Mn in the steel in the vicinity of the steel-oxide interface.The widths of the Crdepleted zone,Mn-accumulated zone and Si-accumulated zone all showed increasing trends with increasing isothermal heating temperature and time.The average values of the diffusion coefficients of Mn,Cr,and Si in the steel at 1473 K(1200℃)were 1.21×10^(^(-14))±2.96×10^(-15),1.69×10^(-14)±2.54×10^(-15),and 1.00×10^(-14)±1.96×10^(-15) m^(2)s^(-1),respectively,and they continued to increase with increasing isothermal heating temperature.
