利用Gleeble-1500D热模拟实验机研究机械合金化法制备的14Cr-ODS铁素体钢在变形温度为1 050-1 200℃、应变速率为0.001-0.3 s 1条件下的高温变形行为,测定其真应力真应变曲线,分析流变应力随应变速率以及变形温度的变化关系。应用MATLA...利用Gleeble-1500D热模拟实验机研究机械合金化法制备的14Cr-ODS铁素体钢在变形温度为1 050-1 200℃、应变速率为0.001-0.3 s 1条件下的高温变形行为,测定其真应力真应变曲线,分析流变应力随应变速率以及变形温度的变化关系。应用MATLAB软件计算最佳的应力水平参数,通过线性回归分析得出材料的变形激活能、材料常数和材料的双曲线本构方程,构造14Cr-ODS铁素体钢的热加工图。结果表明：14Cr-ODS铁素体钢的流变应力随温度升高而减小,随应变速率增加而增大;其变形激活能为501.11 kJ/mol,最佳应力水平参数为0.007,应力指数为4.08;加工失稳温度区域为1 050-1 100℃,应变速率区域为0.1-0.3 s 1;适合加工的条件是变形温度为1 150℃,应变速率为0.1 s 1。展开更多
The effects of chloride,sulfate and carbonate anions on stress corrosion behaviors of ultra-high strength steel 23Co14Ni12Cr3Mo were studied by stress corrosion cracking(SCC)test method using double cantilever beam(DC...The effects of chloride,sulfate and carbonate anions on stress corrosion behaviors of ultra-high strength steel 23Co14Ni12Cr3Mo were studied by stress corrosion cracking(SCC)test method using double cantilever beam(DCB)specimens.The SCC morphology was observed by using scanning electron microscopy(SEM)and the composition of corrosion products was analyzed by using energy dispersive spectrometer(EDS).The results show that the crack propagates to bifurcation in NaCl and Na2SO4 solution,while the crack in Na2CO3 solution propagates along the load direction.The SCC rate in NaCl solution is the highest,while lower in Na2SO4 solution and little in Na2CO3 solution.From the SEM morphologies,quasi-cleavage fracture was observed in NaCl and Na2SO4 solutions,but intergranular features in Na2CO3 solution.The mechanism of anion effect on SCC of steel 23Co14Ni12Cr3Mo was studied by using full immersion test and electrochemical measurements.展开更多
The crack tip stress-strain fields of the elastic-plastic cracked specimens have been analyzed using finite element calculations.The crack initiation and steady propagation behaviours have also been investigated by me...The crack tip stress-strain fields of the elastic-plastic cracked specimens have been analyzed using finite element calculations.The crack initiation and steady propagation behaviours have also been investigated by means of slip line pattern etching technique and mechanical tests. The results show that there are HRR near field and distant field in the crack tip region,and the later depends on the specimen configuration.The crack initiation behaviour is controlled by a single parameter J.In contrast,the steady crack propagation is affected by the distant strain field and can not be described by single parameter only.展开更多
文摘利用Gleeble-1500D热模拟实验机研究机械合金化法制备的14Cr-ODS铁素体钢在变形温度为1 050-1 200℃、应变速率为0.001-0.3 s 1条件下的高温变形行为,测定其真应力真应变曲线,分析流变应力随应变速率以及变形温度的变化关系。应用MATLAB软件计算最佳的应力水平参数,通过线性回归分析得出材料的变形激活能、材料常数和材料的双曲线本构方程,构造14Cr-ODS铁素体钢的热加工图。结果表明：14Cr-ODS铁素体钢的流变应力随温度升高而减小,随应变速率增加而增大;其变形激活能为501.11 kJ/mol,最佳应力水平参数为0.007,应力指数为4.08;加工失稳温度区域为1 050-1 100℃,应变速率区域为0.1-0.3 s 1;适合加工的条件是变形温度为1 150℃,应变速率为0.1 s 1。
基金Project(51171011)supported by the National Science Foundation of China
文摘The effects of chloride,sulfate and carbonate anions on stress corrosion behaviors of ultra-high strength steel 23Co14Ni12Cr3Mo were studied by stress corrosion cracking(SCC)test method using double cantilever beam(DCB)specimens.The SCC morphology was observed by using scanning electron microscopy(SEM)and the composition of corrosion products was analyzed by using energy dispersive spectrometer(EDS).The results show that the crack propagates to bifurcation in NaCl and Na2SO4 solution,while the crack in Na2CO3 solution propagates along the load direction.The SCC rate in NaCl solution is the highest,while lower in Na2SO4 solution and little in Na2CO3 solution.From the SEM morphologies,quasi-cleavage fracture was observed in NaCl and Na2SO4 solutions,but intergranular features in Na2CO3 solution.The mechanism of anion effect on SCC of steel 23Co14Ni12Cr3Mo was studied by using full immersion test and electrochemical measurements.
文摘The crack tip stress-strain fields of the elastic-plastic cracked specimens have been analyzed using finite element calculations.The crack initiation and steady propagation behaviours have also been investigated by means of slip line pattern etching technique and mechanical tests. The results show that there are HRR near field and distant field in the crack tip region,and the later depends on the specimen configuration.The crack initiation behaviour is controlled by a single parameter J.In contrast,the steady crack propagation is affected by the distant strain field and can not be described by single parameter only.
