To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s ...To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s aspect ratio on the microstructure,mechanical properties,work hardening and softening behaviors of Ti_(p)/Mg-5Zn-0.3Ca composites was investigated.The results indicated that the Ti_(p)could be elongated obviously after low-temperature extrusion,and the aspect ratio of which would reach to 13.7:1 as the extrusion temperature deceased to 140℃.Then the“Ti/Mg”layer-like structure was formed in the Ti_(p)/Mg-5Zn-0.3Ca composite.Accompanied with the elongation of Ti_(p),the dynamic recrystallized grains and dynamic precipitates were both refined significantly,however,the dynamic recrystallization rate changed a little.The elongated Ti_(p)endowed the Ti_(p)/Mg-5Zn-0.3Ca composites with better matching of strength and toughness without the sacrifice of elongation and bending strain.Both the work hardening rate and softening rate of Ti_(p)/Mg-5Zn-0.3Ca composites increased with the increasing aspect ratio of Ti_(p).The formation of“Ti/Mg”layer-like structure contributed to the redistribution of strain from large aggregations to a network-like distribution,which effectively suppresses the initiation and propagation of micro-cracks,thus enhancing the plasticity of the Ti_(p)/Mg-5Zn-0.3Ca composites.展开更多
In this work,Ti_(p)/Mg-7Gd-2Y-3Zn(Ti_(p)/GWZ723)composites with various Ti_(p) sizes(~10μm,~20μm and~35μm)were fabricated using semi-solid stirring casting method,the composites were subjected to hot extrusion,and ...In this work,Ti_(p)/Mg-7Gd-2Y-3Zn(Ti_(p)/GWZ723)composites with various Ti_(p) sizes(~10μm,~20μm and~35μm)were fabricated using semi-solid stirring casting method,the composites were subjected to hot extrusion,and the infuence of Ti_(p) size on long-period stacking ordered(LPSO)phase,dynamic recrystallization(DRX),mechanical properties,and work hardening behavior of the Ti_(p)/GWZ723 composites was investigated.The results indicate that with the increase in Ti_(p) size,the grain size of the as-cast Ti_(p)/GWZ723 composites increases,and the lamellar 14H LPSO phase precipitates within the matrix after homogenization treatment.With the increase in Ti_(p) size,the reduction in the Ti_(p) surface area leads to a decrease in surface energy.Consequently,the enrichment of RE element is reduced,which facilitates the formation of the 14H LPSO phase.Moreover,the layer spacing of the 14H LPSO phase decreases.Particle deformation zone(PDZ)is formed around the Ti_(p) after extrusion,promoting the nucleation of DRX.The PDZ size increases with the increase in the Ti_(p) size.Nevertheless,the elongation of the Ti_(p) releases stress and reduces the PDZ size.Simultaneously,the 14H LPSO phase with a small interlayer spacing inhibits the non-basal slip,and the volume fraction of DRX(VDRX)decreases with the increase in the Ti_(p) size.With the increase in Ti_(p) size,the refned grain size and the 14H LPSO phase with smaller interlayer spacing contribute to enhancing the work hardening rate and dynamic recovery rate of the Ti_(p)/GWZ723 composites.The Ti_(p)/Mg laminar-like interface formed in the Ti_(p)/GWZ723 composites can alleviate local stress concentration and inhibit the initiation and propagation of cracks.展开更多
The low-cycle fatigue behavior of powder metallurgy Rene95 alloy containing surface inclusions was investigated by in-situ observation with scanning electron microscopy (SEM). The process of fatigue crack initiation...The low-cycle fatigue behavior of powder metallurgy Rene95 alloy containing surface inclusions was investigated by in-situ observation with scanning electron microscopy (SEM). The process of fatigue crack initiation and early stage of propagation behavior indicates that fatigue crack mainly occurs at the interface between the inclusion and the matrix. The effect of inclusion on the fatigue crack initiation and the early stage of crack growth was very obvious. The fatigue crack growth path in the matrix is similar to the shape of inclusion made on the basis of fatigue fracture image analysis. The empiric relation between the surface and inside crack growth length, near a surface inclusion, can be expressed. Therefore, the fatigue crack growth rate or life of P/M Rene95 alloy including the inclusions can be evaluated on the basis of the measurable surface crack length parameter. In addition, the effect of two inclusions on the fatigue crack initiation behavior was investigated by the in-situ observation with SEM.展开更多
The protective chromium coating was prepared on P110 steel by employing pack cementation.The corrosion behaviors of P110 steel and the obtained coating in CO2-saturated simulated oilfield brine were studied by static ...The protective chromium coating was prepared on P110 steel by employing pack cementation.The corrosion behaviors of P110 steel and the obtained coating in CO2-saturated simulated oilfield brine were studied by static complete immersion tests and electrochemical measurements.The corrosion attacks of the samples were determined by mass loss,corroded surface morphologies,corrosion products,and results of electrochemical measurements.The experimental results showed that the coating was uniform,continuous and compact.The chromium coating was slightly corroded,and the mass loss and corrosion rate of the coating were far lower than those of P110 steel.Chromium coating has higher self-corroding potential and lower corrosion current density than P110 steel in accordance with the electrochemical tests results.Taken as a whole,chromizing treatment has significantly improved the corrosion resistance of P110 steel.展开更多
Event-related potential studies of cognitive function in addiction behaviors have focused on the P300 event-related potential component. The current study investigated the association between P300 component and Intern...Event-related potential studies of cognitive function in addiction behaviors have focused on the P300 event-related potential component. The current study investigated the association between P300 component and Internet addiction disorder. We found that individuals with Internet addiction disorder exhibited significantly longer P300 latencies than controls (N2: P = 0.035; P3a: P = 0.031 P3b: P = 0.043) and similar P300 amplitudes compared to control participants. After 3 months of cognitive behavioral therapy, P300 latencies decreased significantly in the P3a and P3b (P3a: P = 0.045; P3b: P = 0.062). These results suggest that deficits in cognitive function may be involved in Internet addiction disorder, and that clinical psychological treatment may be effective.展开更多
The effects of hot extrusion and addition of Al_(2)O_(3p) on both microstructure and tribological behavior of 7075 composites were investigated via optical microscopy(OM),scanning electron microscopy(SEM),energy dispe...The effects of hot extrusion and addition of Al_(2)O_(3p) on both microstructure and tribological behavior of 7075 composites were investigated via optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).The experimental consequences reveal that the optimal addition of Al_(2)O_(3p) was 2 wt%.After hot extrusion,the Mg(Zn,Cu,Al)2 phases partially dissolve into the matrix and generate many uniformly distributed aging precipitation particles,the Al_(7)Cu_(2)Fe phases are squeezed and broken,and the Al_(2)O_(3p) become uniform distribution.The microhardness of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites reaches HV 170.34,increased by 41.5%than as-cast composites.The wear rate of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites is further lower than that of as-cast composites under the same condition.SEM-EDS analyses reveal that the reinforced wear resistance of composites can put down to the protective effect of the Al_(2)O_(3p) reinforced transition layer.After hot extrusion,the transition layer becomes stable,which determines the reinforced wear resistance of the as-extruded composites.展开更多
Comparing with the predictions of the transitional dynamical symmetry E(5) proposed by Iachello [Phys. Rev. Lett. 85 (2000) 3580], the critical behaviors from U(5)-0(6) are studied in the space of two control ...Comparing with the predictions of the transitional dynamical symmetry E(5) proposed by Iachello [Phys. Rev. Lett. 85 (2000) 3580], the critical behaviors from U(5)-0(6) are studied in the space of two control parameters in the interacting boson model. A simple shape phase diagram has been presented. It is found that E(5) predictions cannot be exactly reproduced by our calculations and that the best agreement is close to the calculations with boson number N = 9. By comparing with experimental data on E(5)-like nuclei, we find that E(5) predictions and IBM calculations can reproduce the energy ratios and E2 transition ones.展开更多
The effect of particle deformation zone(PDZ) on the microstructure and mechanical properties of SiC_(p)/Mg-5Zn composites was studied.Meanwhile,the work hardening and so ftening behavior of SiC_(p)/Mg-5Zn composites i...The effect of particle deformation zone(PDZ) on the microstructure and mechanical properties of SiC_(p)/Mg-5Zn composites was studied.Meanwhile,the work hardening and so ftening behavior of SiC_(p)/Mg-5Zn composites influenced by PDZ size were analyzed and discussed using neutron diffraction under in-situ tensile deformation.The evolution of FWHM(full width at half maximum) extracted from the diffraction pattern of SiC_(p)/Mg-5Zn composites was used to interpret the modification of dislocation density during in-situ tension,which discovered the effect of dislocation on the work hardening behavior of SiC_(p)/Mg-5Zn composites.In addition,the tensile stress reduction(△P_i) values during in-situ tension test were calculated to analyze the effect of PDZ size on the softening behavior of SiC_(p)/Mg-5Zn composites.The results show that the work hardening rate of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size,which was attributed to the grain size of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size.Moreover,the stress reduction(△P_i) values increased continuously during in-situ tensile for SiC_(p)/Mg-5Zn composites due to the increased stored energy produced during plastic deformation,which provided a driving force for the softening effect.However,the effect of grain size on the softening behavior is greater than that of the stored energy,which led to the tensile stress reduction(△P_i) values of P30(d_(PDZ)=30 μm)-SiC_(p)/Mg-5Zn composite were higher than that of P60(d_(PDZ)=60 μm)-SiC_(p)/Mg-5Zn composite when the ε_(ri) were 0.25,0.5,0.75 and 1,respectively.展开更多
The electroplating behavior of Zn P alloy on copper from light acid chloride solutions (LACS) was investigated using cyclic voltammetry and linear potential sweep method. It is found that, under the experimental condi...The electroplating behavior of Zn P alloy on copper from light acid chloride solutions (LACS) was investigated using cyclic voltammetry and linear potential sweep method. It is found that, under the experimental conditions, the concentrations of H 3PO 3 and ascorbic acid in LACS change the codeposition mechanism of Zn P alloy, the addition of H 3PO 3 into LACS promotes the three dimentional (3 D) instantaneous nucleation/growth, while the addition of ascorbic acid promotes the two dimentional (2 D) instantaneous nucleation and layer by layer growth. H 3PO 3 and zinc ions inhibit the deposition each other. The experimental results also show that H 3PO 3 in the LACS can be reduced on the cathode individually, and low pH value of the LACS promotes the reduction of H 3PO 3.展开更多
In modern fossil and nuclear power plants,the components are subjected to creep,fatigue,and creep-fatigue(CF)due to frequent start-up and shut-down operations at high temperatures.The CF interaction on the in-service ...In modern fossil and nuclear power plants,the components are subjected to creep,fatigue,and creep-fatigue(CF)due to frequent start-up and shut-down operations at high temperatures.The CF interaction on the in-service P92 steel welded joint was investigated by strain-controlled CF tests with different dwell times of 30,120,300,600 and 900 s at 650℃.Based on the observations of the fracture surface by scanning electron microscope(SEM),the character-istic microstructure of fatigue-induced damage was found for the CF specimens with short dwell times(30 and 120 s).The hardness,elastic modulus and creep deformation near the fracture edges of four typical CF specimens with 30,120,600 and 900 s dwell times were measured by nanoindentation.Compared to specimens with post-weld heat treatment(PWHT),lower hardness and creep strength were found for all CF specimens.In addition,significant reduc-tions in hardness,elastic modulus,and creep strength were measured near the fracture edges for the CF specimens with short dwell times compared to the PWHT specimens.Compared to PWHT specimens(0.007),the increased strain rate sensitivities(SRS)of 0.010 to 0.17 were estimated from secondary creep.The increased values of SRS indicate that the room temperature creeps behavior is strongly affected by the decrease in dislocation density after the CF tests.展开更多
基金supported by the“National Natural Science Foundation of China”(Grants.52271109 and 52001223)Support from the“National Key Research and Development Program for Young Scientists”(Grant.2021YFB3703300)+1 种基金the Major Special Plan for Science and Technology in Shanxi Province(202201050201012)the Special Fund Project for Guiding Local Science and Technology Development by the Central Government(Grant.YDZJSX2021B019)。
文摘To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s aspect ratio on the microstructure,mechanical properties,work hardening and softening behaviors of Ti_(p)/Mg-5Zn-0.3Ca composites was investigated.The results indicated that the Ti_(p)could be elongated obviously after low-temperature extrusion,and the aspect ratio of which would reach to 13.7:1 as the extrusion temperature deceased to 140℃.Then the“Ti/Mg”layer-like structure was formed in the Ti_(p)/Mg-5Zn-0.3Ca composite.Accompanied with the elongation of Ti_(p),the dynamic recrystallized grains and dynamic precipitates were both refined significantly,however,the dynamic recrystallization rate changed a little.The elongated Ti_(p)endowed the Ti_(p)/Mg-5Zn-0.3Ca composites with better matching of strength and toughness without the sacrifice of elongation and bending strain.Both the work hardening rate and softening rate of Ti_(p)/Mg-5Zn-0.3Ca composites increased with the increasing aspect ratio of Ti_(p).The formation of“Ti/Mg”layer-like structure contributed to the redistribution of strain from large aggregations to a network-like distribution,which effectively suppresses the initiation and propagation of micro-cracks,thus enhancing the plasticity of the Ti_(p)/Mg-5Zn-0.3Ca composites.
基金supported by the National Natural Science Foundation of China(Grant Nos.52271109 and 52401162)support from the Natural Science Foundation of Shanxi(Grant Nos.202403021211064 and 202403011212003)the Major Special Plan for Science and Technology in Shanxi Province(202201050201012).
文摘In this work,Ti_(p)/Mg-7Gd-2Y-3Zn(Ti_(p)/GWZ723)composites with various Ti_(p) sizes(~10μm,~20μm and~35μm)were fabricated using semi-solid stirring casting method,the composites were subjected to hot extrusion,and the infuence of Ti_(p) size on long-period stacking ordered(LPSO)phase,dynamic recrystallization(DRX),mechanical properties,and work hardening behavior of the Ti_(p)/GWZ723 composites was investigated.The results indicate that with the increase in Ti_(p) size,the grain size of the as-cast Ti_(p)/GWZ723 composites increases,and the lamellar 14H LPSO phase precipitates within the matrix after homogenization treatment.With the increase in Ti_(p) size,the reduction in the Ti_(p) surface area leads to a decrease in surface energy.Consequently,the enrichment of RE element is reduced,which facilitates the formation of the 14H LPSO phase.Moreover,the layer spacing of the 14H LPSO phase decreases.Particle deformation zone(PDZ)is formed around the Ti_(p) after extrusion,promoting the nucleation of DRX.The PDZ size increases with the increase in the Ti_(p) size.Nevertheless,the elongation of the Ti_(p) releases stress and reduces the PDZ size.Simultaneously,the 14H LPSO phase with a small interlayer spacing inhibits the non-basal slip,and the volume fraction of DRX(VDRX)decreases with the increase in the Ti_(p) size.With the increase in Ti_(p) size,the refned grain size and the 14H LPSO phase with smaller interlayer spacing contribute to enhancing the work hardening rate and dynamic recovery rate of the Ti_(p)/GWZ723 composites.The Ti_(p)/Mg laminar-like interface formed in the Ti_(p)/GWZ723 composites can alleviate local stress concentration and inhibit the initiation and propagation of cracks.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50571047) and the National BasicResearch Program of China (No.2004CB619304).
文摘The low-cycle fatigue behavior of powder metallurgy Rene95 alloy containing surface inclusions was investigated by in-situ observation with scanning electron microscopy (SEM). The process of fatigue crack initiation and early stage of propagation behavior indicates that fatigue crack mainly occurs at the interface between the inclusion and the matrix. The effect of inclusion on the fatigue crack initiation and the early stage of crack growth was very obvious. The fatigue crack growth path in the matrix is similar to the shape of inclusion made on the basis of fatigue fracture image analysis. The empiric relation between the surface and inside crack growth length, near a surface inclusion, can be expressed. Therefore, the fatigue crack growth rate or life of P/M Rene95 alloy including the inclusions can be evaluated on the basis of the measurable surface crack length parameter. In addition, the effect of two inclusions on the fatigue crack initiation behavior was investigated by the in-situ observation with SEM.
基金Funded by the Science and Technology Programs for Research and Development of Shaanxi Province (No.2008K01-31)
文摘The protective chromium coating was prepared on P110 steel by employing pack cementation.The corrosion behaviors of P110 steel and the obtained coating in CO2-saturated simulated oilfield brine were studied by static complete immersion tests and electrochemical measurements.The corrosion attacks of the samples were determined by mass loss,corroded surface morphologies,corrosion products,and results of electrochemical measurements.The experimental results showed that the coating was uniform,continuous and compact.The chromium coating was slightly corroded,and the mass loss and corrosion rate of the coating were far lower than those of P110 steel.Chromium coating has higher self-corroding potential and lower corrosion current density than P110 steel in accordance with the electrochemical tests results.Taken as a whole,chromizing treatment has significantly improved the corrosion resistance of P110 steel.
基金the Shanxi Soft Science Research Program, No. 2008041061-03
文摘Event-related potential studies of cognitive function in addiction behaviors have focused on the P300 event-related potential component. The current study investigated the association between P300 component and Internet addiction disorder. We found that individuals with Internet addiction disorder exhibited significantly longer P300 latencies than controls (N2: P = 0.035; P3a: P = 0.031 P3b: P = 0.043) and similar P300 amplitudes compared to control participants. After 3 months of cognitive behavioral therapy, P300 latencies decreased significantly in the P3a and P3b (P3a: P = 0.045; P3b: P = 0.062). These results suggest that deficits in cognitive function may be involved in Internet addiction disorder, and that clinical psychological treatment may be effective.
基金Project(51965040)supported by the National Natural Science Foundation of ChinaProject(20181BAB206026)supported by the National Science Foundation of Jiangxi Province,China。
文摘The effects of hot extrusion and addition of Al_(2)O_(3p) on both microstructure and tribological behavior of 7075 composites were investigated via optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).The experimental consequences reveal that the optimal addition of Al_(2)O_(3p) was 2 wt%.After hot extrusion,the Mg(Zn,Cu,Al)2 phases partially dissolve into the matrix and generate many uniformly distributed aging precipitation particles,the Al_(7)Cu_(2)Fe phases are squeezed and broken,and the Al_(2)O_(3p) become uniform distribution.The microhardness of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites reaches HV 170.34,increased by 41.5%than as-cast composites.The wear rate of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites is further lower than that of as-cast composites under the same condition.SEM-EDS analyses reveal that the reinforced wear resistance of composites can put down to the protective effect of the Al_(2)O_(3p) reinforced transition layer.After hot extrusion,the transition layer becomes stable,which determines the reinforced wear resistance of the as-extruded composites.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10265001 and 10547003, the Natural Science Foundation of Inner Mongolian under Grant No. 200607010111, and the Key Scientific Research Fund of Educational Bureau of Inner Mongolian under Grant No. NJ05007 .Acknowledgments The authors are greatly indebted to Prof. G.L. Long for his continuing interest in this work and his many suggestions.
文摘Comparing with the predictions of the transitional dynamical symmetry E(5) proposed by Iachello [Phys. Rev. Lett. 85 (2000) 3580], the critical behaviors from U(5)-0(6) are studied in the space of two control parameters in the interacting boson model. A simple shape phase diagram has been presented. It is found that E(5) predictions cannot be exactly reproduced by our calculations and that the best agreement is close to the calculations with boson number N = 9. By comparing with experimental data on E(5)-like nuclei, we find that E(5) predictions and IBM calculations can reproduce the energy ratios and E2 transition ones.
基金supported financially by the National Natural Science Foundation of China(Nos.51771128 and 51771129)the Shanxi Province Science and Technology Major Projects(No.20181101008)the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi。
文摘The effect of particle deformation zone(PDZ) on the microstructure and mechanical properties of SiC_(p)/Mg-5Zn composites was studied.Meanwhile,the work hardening and so ftening behavior of SiC_(p)/Mg-5Zn composites influenced by PDZ size were analyzed and discussed using neutron diffraction under in-situ tensile deformation.The evolution of FWHM(full width at half maximum) extracted from the diffraction pattern of SiC_(p)/Mg-5Zn composites was used to interpret the modification of dislocation density during in-situ tension,which discovered the effect of dislocation on the work hardening behavior of SiC_(p)/Mg-5Zn composites.In addition,the tensile stress reduction(△P_i) values during in-situ tension test were calculated to analyze the effect of PDZ size on the softening behavior of SiC_(p)/Mg-5Zn composites.The results show that the work hardening rate of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size,which was attributed to the grain size of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size.Moreover,the stress reduction(△P_i) values increased continuously during in-situ tensile for SiC_(p)/Mg-5Zn composites due to the increased stored energy produced during plastic deformation,which provided a driving force for the softening effect.However,the effect of grain size on the softening behavior is greater than that of the stored energy,which led to the tensile stress reduction(△P_i) values of P30(d_(PDZ)=30 μm)-SiC_(p)/Mg-5Zn composite were higher than that of P60(d_(PDZ)=60 μm)-SiC_(p)/Mg-5Zn composite when the ε_(ri) were 0.25,0.5,0.75 and 1,respectively.
文摘The electroplating behavior of Zn P alloy on copper from light acid chloride solutions (LACS) was investigated using cyclic voltammetry and linear potential sweep method. It is found that, under the experimental conditions, the concentrations of H 3PO 3 and ascorbic acid in LACS change the codeposition mechanism of Zn P alloy, the addition of H 3PO 3 into LACS promotes the three dimentional (3 D) instantaneous nucleation/growth, while the addition of ascorbic acid promotes the two dimentional (2 D) instantaneous nucleation and layer by layer growth. H 3PO 3 and zinc ions inhibit the deposition each other. The experimental results also show that H 3PO 3 in the LACS can be reduced on the cathode individually, and low pH value of the LACS promotes the reduction of H 3PO 3.
基金Supported by National 13th Five-Year Key Technologies R&D Program of China(Grant No.2016YFC0801902)National Natural Science Foundation of China(Grant No.11727803,11672356,52075490)Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.RF-A2020010).
文摘In modern fossil and nuclear power plants,the components are subjected to creep,fatigue,and creep-fatigue(CF)due to frequent start-up and shut-down operations at high temperatures.The CF interaction on the in-service P92 steel welded joint was investigated by strain-controlled CF tests with different dwell times of 30,120,300,600 and 900 s at 650℃.Based on the observations of the fracture surface by scanning electron microscope(SEM),the character-istic microstructure of fatigue-induced damage was found for the CF specimens with short dwell times(30 and 120 s).The hardness,elastic modulus and creep deformation near the fracture edges of four typical CF specimens with 30,120,600 and 900 s dwell times were measured by nanoindentation.Compared to specimens with post-weld heat treatment(PWHT),lower hardness and creep strength were found for all CF specimens.In addition,significant reduc-tions in hardness,elastic modulus,and creep strength were measured near the fracture edges for the CF specimens with short dwell times compared to the PWHT specimens.Compared to PWHT specimens(0.007),the increased strain rate sensitivities(SRS)of 0.010 to 0.17 were estimated from secondary creep.The increased values of SRS indicate that the room temperature creeps behavior is strongly affected by the decrease in dislocation density after the CF tests.