Coarsening,embrittlement and corrosion sensitization in a high temperature heat-affected zone(HTHAZ) are the major problems when 12%chromium low carbon stainless steel is being welded,which induce the deterioration of...Coarsening,embrittlement and corrosion sensitization in a high temperature heat-affected zone(HTHAZ) are the major problems when 12%chromium low carbon stainless steel is being welded,which induce the deterioration of the impact toughness at a low temperature and intergranular corrosion resistance property.This study investigates the corresponding microstructures in HTHAZ with different chemical compositions and heat inputs through thermal simulation tests.The results show that the martensite content increases with the descending of ferrite factor(FF) when FF is below 9.0 and heat input influences the microstructure of high FF steel in HTHAZ.Martensite of 12%Cr stainless steel in HTHAZ with only Nb stabilization reticularly distributes at ferrite grain boundaries.展开更多
This study analyzed the effect of cold-rolling reduction(in a wide range of 10%-80%) and subsequent annealing on the microstructure and mechanical properties of AISI 301 LN stainless steel.Results indicated the format...This study analyzed the effect of cold-rolling reduction(in a wide range of 10%-80%) and subsequent annealing on the microstructure and mechanical properties of AISI 301 LN stainless steel.Results indicated the formation of shear bands and nucleation of strain-induced α'-martensite at their intersections.The volume fraction of α'-martensite increased with increase in cold-rolling reduction by the continuous growth of embryos.This,in turn,resulted in an increase in yield and tensile strengths.The reversion of α'-martensite to austenite occurred after subsequent annealing.The observed variation in the grain size of reversed austenite can be related to the annealing regime.A good combination of strength and ductility can be obtained upon annealing at 650℃ for 30 min.The effect of grain size on yield strength conformed to the Hall-Petch relationship in the entire range of our analysis.展开更多
Two ferrite-martensite stainless steels(FMSSs)were developed by Baosteel based on the T4003 composition,through optimizing the manganese and nickel contents,reducing silicon,carbon and nitrogen contents,controlling re...Two ferrite-martensite stainless steels(FMSSs)were developed by Baosteel based on the T4003 composition,through optimizing the manganese and nickel contents,reducing silicon,carbon and nitrogen contents,controlling remnant niobium and molybdenum,adding sufficient titanium and controlling the processing.In this study,the physical metallurgy of such FMSSs was investigated with the emphasis on the alloying effect on the phase balance during processing and the transformation behavior during welding for different microstructures.In addition,the mechanical behavior and the weldability were investigated.The results indicate that such steels have a good combination of strength and toughness and better weldability compared with the traditional 1.4003 steel.Such high strength steels are highly suitable for railway cargo transportation where the wall thickness of the wagons can be reduced,resulting in weight savings.展开更多
文摘Coarsening,embrittlement and corrosion sensitization in a high temperature heat-affected zone(HTHAZ) are the major problems when 12%chromium low carbon stainless steel is being welded,which induce the deterioration of the impact toughness at a low temperature and intergranular corrosion resistance property.This study investigates the corresponding microstructures in HTHAZ with different chemical compositions and heat inputs through thermal simulation tests.The results show that the martensite content increases with the descending of ferrite factor(FF) when FF is below 9.0 and heat input influences the microstructure of high FF steel in HTHAZ.Martensite of 12%Cr stainless steel in HTHAZ with only Nb stabilization reticularly distributes at ferrite grain boundaries.
基金supported by the State 863 Projects of China under the grant No.2008AA030702
文摘This study analyzed the effect of cold-rolling reduction(in a wide range of 10%-80%) and subsequent annealing on the microstructure and mechanical properties of AISI 301 LN stainless steel.Results indicated the formation of shear bands and nucleation of strain-induced α'-martensite at their intersections.The volume fraction of α'-martensite increased with increase in cold-rolling reduction by the continuous growth of embryos.This,in turn,resulted in an increase in yield and tensile strengths.The reversion of α'-martensite to austenite occurred after subsequent annealing.The observed variation in the grain size of reversed austenite can be related to the annealing regime.A good combination of strength and ductility can be obtained upon annealing at 650℃ for 30 min.The effect of grain size on yield strength conformed to the Hall-Petch relationship in the entire range of our analysis.
文摘Two ferrite-martensite stainless steels(FMSSs)were developed by Baosteel based on the T4003 composition,through optimizing the manganese and nickel contents,reducing silicon,carbon and nitrogen contents,controlling remnant niobium and molybdenum,adding sufficient titanium and controlling the processing.In this study,the physical metallurgy of such FMSSs was investigated with the emphasis on the alloying effect on the phase balance during processing and the transformation behavior during welding for different microstructures.In addition,the mechanical behavior and the weldability were investigated.The results indicate that such steels have a good combination of strength and toughness and better weldability compared with the traditional 1.4003 steel.Such high strength steels are highly suitable for railway cargo transportation where the wall thickness of the wagons can be reduced,resulting in weight savings.
