Modified CNS-Ⅱ F/M steel was designed for in-core components of supercritical water cooled reactor. Study on the hot deformation behavior of modified CNS- Ⅱ F/M steel is of great importance for processing parameter ...Modified CNS-Ⅱ F/M steel was designed for in-core components of supercritical water cooled reactor. Study on the hot deformation behavior of modified CNS- Ⅱ F/M steel is of great importance for processing parameter planning and microstructure controlling during hot deformation. The hot deformation behavior of modified CNS-Ⅱ F/M steel was investigated through isothermal hot compression test at temperature ranging from 1 223 to 1 373 K and strain rate 0.01 to 10 s^-1. The true stress true strain data gained from compression tests were used to built constitu- tive equation of modified CNS-Ⅱ F/M steel. The influence of strain on the accuracy of constitutive analysis was in corporated, assuming strain has a influence on material constants. A 5th order polynominal equation with very good accuracy was used to represent the influence of strain on material constant. The flow stresses calculated from the constitutive equation were compared with test values in the whole experiment range and the absolute average error for the constitutive equation in predicting fl.ow stress is 4. 728 %. At last, the recrystallization behavior of modified CNS-Ⅱ F/M steel was investigated. The relationship of critical strain and peak strain with Zener-Hollomon parameter were given by an experimental equation.展开更多
An ODS （oxide dispersion strengthened） steels are one of the most notable structural materials being developed for future high-temperature energy production technologies, and several studies have been devoted to the...An ODS （oxide dispersion strengthened） steels are one of the most notable structural materials being developed for future high-temperature energy production technologies, and several studies have been devoted to the development of ODS materials for such applications. However, only little paper focuses on corrosion behavior of F/M （ferritic martensictic） and ODS steels. The corrosion behavior of 11% Cr F/M steel and 15% Cr ODS steel were evaluated using electrochemical methods in borate buffer and 1 kmol m＂3 HNO3 with or without NaCI and also in boiling 60% nitric acid. The corrosion resistance results clearly indicated the influences of steel alloys composition and chloride ions. The XPS （X-ray photo-electron spectroscopy） results of the pre-passivated surface revealed that the oxide formed were composed predominantly of Fe203 along with Cr203, and Y203 layers in ODS steel. The corrosion rate measured in boiling nitric acid for 48 h for both the steels shows high corrosion rate in boiling condition. The SEM （scanning electron microscopy） observation of the pit morphology after corrosion tests appears with shallow pit in both steel surfaces The corrosion degradation behavior in relation to the composition of the passive oxide film in different electrolytic solutions is discussed in this paper.展开更多
采用Gleeble-3500对铁素体/马氏体(F/M)钢的热成形规律进行了研究。基于F/M钢热压缩应力-应变曲线,建立了F/M钢动态材料模型(dynamic material model,DMM)热加工图,并通过金相分析对热加工图进行了验证。结合热加工图和金相分析,研究了...采用Gleeble-3500对铁素体/马氏体(F/M)钢的热成形规律进行了研究。基于F/M钢热压缩应力-应变曲线,建立了F/M钢动态材料模型(dynamic material model,DMM)热加工图,并通过金相分析对热加工图进行了验证。结合热加工图和金相分析,研究了F/M钢热成形过程中的组织变化,给出了不同情况下的热加工参数:如后续需要继续大变形加工,可采用850℃、应变速率0.01 s^-1作为加工参数,该参数可生成细小、均匀且易加工的铁素体组织;如后续对F/M钢有较高的强度要求,可选取1150℃、应变速率10 s^-1作为加工参数,该参数可生成细小、均匀且高强度的马氏体。展开更多
本文研究了热轧 F+(M+B)双相钢线材的生产及其在高强钢丝上的应用.指出在双相钢线材拉拔过程中存在于 F 晶界及尺寸较小的岛状第二相协调 F 变形.而尺寸较大的块状 M 则通过切变破裂直至破碎.这种变形机制使 F+(M+B)双相钢线材不经任何...本文研究了热轧 F+(M+B)双相钢线材的生产及其在高强钢丝上的应用.指出在双相钢线材拉拔过程中存在于 F 晶界及尺寸较小的岛状第二相协调 F 变形.而尺寸较大的块状 M 则通过切变破裂直至破碎.这种变形机制使 F+(M+B)双相钢线材不经任何热处理,就具有总面缩率为97.6%的深加工性能,强度可达1800MPa 以上.本文还对双相钢钢丝的应用进行了研究取得了较好的效果.展开更多
文摘Modified CNS-Ⅱ F/M steel was designed for in-core components of supercritical water cooled reactor. Study on the hot deformation behavior of modified CNS- Ⅱ F/M steel is of great importance for processing parameter planning and microstructure controlling during hot deformation. The hot deformation behavior of modified CNS-Ⅱ F/M steel was investigated through isothermal hot compression test at temperature ranging from 1 223 to 1 373 K and strain rate 0.01 to 10 s^-1. The true stress true strain data gained from compression tests were used to built constitu- tive equation of modified CNS-Ⅱ F/M steel. The influence of strain on the accuracy of constitutive analysis was in corporated, assuming strain has a influence on material constants. A 5th order polynominal equation with very good accuracy was used to represent the influence of strain on material constant. The flow stresses calculated from the constitutive equation were compared with test values in the whole experiment range and the absolute average error for the constitutive equation in predicting fl.ow stress is 4. 728 %. At last, the recrystallization behavior of modified CNS-Ⅱ F/M steel was investigated. The relationship of critical strain and peak strain with Zener-Hollomon parameter were given by an experimental equation.
文摘An ODS （oxide dispersion strengthened） steels are one of the most notable structural materials being developed for future high-temperature energy production technologies, and several studies have been devoted to the development of ODS materials for such applications. However, only little paper focuses on corrosion behavior of F/M （ferritic martensictic） and ODS steels. The corrosion behavior of 11% Cr F/M steel and 15% Cr ODS steel were evaluated using electrochemical methods in borate buffer and 1 kmol m＂3 HNO3 with or without NaCI and also in boiling 60% nitric acid. The corrosion resistance results clearly indicated the influences of steel alloys composition and chloride ions. The XPS （X-ray photo-electron spectroscopy） results of the pre-passivated surface revealed that the oxide formed were composed predominantly of Fe203 along with Cr203, and Y203 layers in ODS steel. The corrosion rate measured in boiling nitric acid for 48 h for both the steels shows high corrosion rate in boiling condition. The SEM （scanning electron microscopy） observation of the pit morphology after corrosion tests appears with shallow pit in both steel surfaces The corrosion degradation behavior in relation to the composition of the passive oxide film in different electrolytic solutions is discussed in this paper.
文摘采用Gleeble-3500对铁素体/马氏体(F/M)钢的热成形规律进行了研究。基于F/M钢热压缩应力-应变曲线,建立了F/M钢动态材料模型(dynamic material model,DMM)热加工图,并通过金相分析对热加工图进行了验证。结合热加工图和金相分析,研究了F/M钢热成形过程中的组织变化,给出了不同情况下的热加工参数:如后续需要继续大变形加工,可采用850℃、应变速率0.01 s^-1作为加工参数,该参数可生成细小、均匀且易加工的铁素体组织;如后续对F/M钢有较高的强度要求,可选取1150℃、应变速率10 s^-1作为加工参数,该参数可生成细小、均匀且高强度的马氏体。
文摘本文研究了热轧 F+(M+B)双相钢线材的生产及其在高强钢丝上的应用.指出在双相钢线材拉拔过程中存在于 F 晶界及尺寸较小的岛状第二相协调 F 变形.而尺寸较大的块状 M 则通过切变破裂直至破碎.这种变形机制使 F+(M+B)双相钢线材不经任何热处理,就具有总面缩率为97.6%的深加工性能,强度可达1800MPa 以上.本文还对双相钢钢丝的应用进行了研究取得了较好的效果.
