The effect of cobalt on chemical segregation and solution process in three nickel base single crystal superalloys was investigated. Three alloys containing the mass fraction of cobalt of 12% (named Alloy 1), 3% (named...The effect of cobalt on chemical segregation and solution process in three nickel base single crystal superalloys was investigated. Three alloys containing the mass fraction of cobalt of 12% (named Alloy 1), 3% (named Alloy 2) and 0 (named Alloy 3), respectively were studied, in which the contents of other elements were same. The results show that the segregation extent of W, Re, Ta, Al between dendrite and interdendritic region rises with the increase of cobalt content. The incipient melting points decrease by 10℃and 20℃respectively when the content of cobalt increases from 0 through 3% to 12%. During solid solution at 1 340℃, the solid solution of large gamma prime in interdendritic region and the dissolution of eutectic in alloy 1 become easier than in other two alloys. After heat-treatment at 1 340℃for 8 h, the segregation extent of elements in alloy 1 decreases dramatically, while in alloy 2 and alloy 3, the segregation ratios decrease slowly. It suggests that the higher content of cobalt can accelerate the diffusion process at high temperature.展开更多
Beiman Special Steel Share Limited Company and Chan gchun No.1 Automobile Manufacturing Factory took samples on the adjacent parts of 5 batches of 40CrH steel bars and carried out the hardenability test. The results i...Beiman Special Steel Share Limited Company and Chan gchun No.1 Automobile Manufacturing Factory took samples on the adjacent parts of 5 batches of 40CrH steel bars and carried out the hardenability test. The results indicated that the experimental results of the adjacent samples almo st agreed with each other. It can be thought that the difference between the primary experimental results made by the two units is caused by the segregation of chemical compositions (C, Mn and Cr).展开更多
文摘The effect of cobalt on chemical segregation and solution process in three nickel base single crystal superalloys was investigated. Three alloys containing the mass fraction of cobalt of 12% (named Alloy 1), 3% (named Alloy 2) and 0 (named Alloy 3), respectively were studied, in which the contents of other elements were same. The results show that the segregation extent of W, Re, Ta, Al between dendrite and interdendritic region rises with the increase of cobalt content. The incipient melting points decrease by 10℃and 20℃respectively when the content of cobalt increases from 0 through 3% to 12%. During solid solution at 1 340℃, the solid solution of large gamma prime in interdendritic region and the dissolution of eutectic in alloy 1 become easier than in other two alloys. After heat-treatment at 1 340℃for 8 h, the segregation extent of elements in alloy 1 decreases dramatically, while in alloy 2 and alloy 3, the segregation ratios decrease slowly. It suggests that the higher content of cobalt can accelerate the diffusion process at high temperature.
文摘Beiman Special Steel Share Limited Company and Chan gchun No.1 Automobile Manufacturing Factory took samples on the adjacent parts of 5 batches of 40CrH steel bars and carried out the hardenability test. The results indicated that the experimental results of the adjacent samples almo st agreed with each other. It can be thought that the difference between the primary experimental results made by the two units is caused by the segregation of chemical compositions (C, Mn and Cr).
