The hot ductility of Fe-36Ni invar alloy with different additions of the element cerium was investigated using a Gleeble-3800 thermal-mechanical simulator over the temperature range 850 - 1 050℃, and the improvement ...The hot ductility of Fe-36Ni invar alloy with different additions of the element cerium was investigated using a Gleeble-3800 thermal-mechanical simulator over the temperature range 850 - 1 050℃, and the improvement mechanism of the hot ductility was analyzed using a combination of SEM, EDS, and OM. The results indicated that Fe-36Ni invar alloy exhibited poor hot ductility below 1 050℃, which was mainly attributed to weak grain boundaries and the action of grain boundary sliding. However, the alloys with cerium contents of 0. 016% and 0.024% both demonstrated substantial improvement in the hot ductility over the entire testing temperature range. The observed improvement of the hot ductility of the alloy with 0. 016% cerium at 950 ~C and the alloy with 0.024% cerium at 900℃ was associated mainly with the grain boundary strengthening and the restriction of the grain boundary sliding because the addition of cerium reduced the segregation of sulfur at grain boundaries and refined the grain structure. The occurrence and acceleration of dynamic recrystallization were found to be responsible for the high hot ductility of the alloy with 0.016% cerium at 1 000℃ and the alloy with 0. 024% cerium at 950 - 1 000℃ as a result of the refinement of the grain structure by addition of cerium.展开更多
Corrosion behavior of a Ni-16Mo-7Cr base superalloy was systematically investigated under a selenium(Se)atmosphere at 700°C.It shows that Se can react with the alloy elements such as Ni,Mo,Cr et al.to form a reac...Corrosion behavior of a Ni-16Mo-7Cr base superalloy was systematically investigated under a selenium(Se)atmosphere at 700°C.It shows that Se can react with the alloy elements such as Ni,Mo,Cr et al.to form a reaction layer at the surface of alloy,which is mainly composed of Ni_(2)Se_(3),MoSe_(2),and Cr_(3)Se_(4).The tensile properties of the alloy are not greatly affected by changes of Se content.The slight decrease in the tensile strength is attributed to the formation of the reaction layer,which leads to the decrease in the effective undertaking area of the alloy.No intergranular diffusion characteristic of Se elements was observed,and the Se effect of embrittlement on grain boundaries is weaker than that of tellurium(Te).展开更多
文摘The hot ductility of Fe-36Ni invar alloy with different additions of the element cerium was investigated using a Gleeble-3800 thermal-mechanical simulator over the temperature range 850 - 1 050℃, and the improvement mechanism of the hot ductility was analyzed using a combination of SEM, EDS, and OM. The results indicated that Fe-36Ni invar alloy exhibited poor hot ductility below 1 050℃, which was mainly attributed to weak grain boundaries and the action of grain boundary sliding. However, the alloys with cerium contents of 0. 016% and 0.024% both demonstrated substantial improvement in the hot ductility over the entire testing temperature range. The observed improvement of the hot ductility of the alloy with 0. 016% cerium at 950 ~C and the alloy with 0.024% cerium at 900℃ was associated mainly with the grain boundary strengthening and the restriction of the grain boundary sliding because the addition of cerium reduced the segregation of sulfur at grain boundaries and refined the grain structure. The occurrence and acceleration of dynamic recrystallization were found to be responsible for the high hot ductility of the alloy with 0.016% cerium at 1 000℃ and the alloy with 0. 024% cerium at 950 - 1 000℃ as a result of the refinement of the grain structure by addition of cerium.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.52071331,51901241,52001322).
文摘Corrosion behavior of a Ni-16Mo-7Cr base superalloy was systematically investigated under a selenium(Se)atmosphere at 700°C.It shows that Se can react with the alloy elements such as Ni,Mo,Cr et al.to form a reaction layer at the surface of alloy,which is mainly composed of Ni_(2)Se_(3),MoSe_(2),and Cr_(3)Se_(4).The tensile properties of the alloy are not greatly affected by changes of Se content.The slight decrease in the tensile strength is attributed to the formation of the reaction layer,which leads to the decrease in the effective undertaking area of the alloy.No intergranular diffusion characteristic of Se elements was observed,and the Se effect of embrittlement on grain boundaries is weaker than that of tellurium(Te).
