High purity hot hydrogen charging at high temperature was used to investigate the hydrogen embrittlement (HE) of JBK-75 alloys with different contents of P and Si(Mn). The results indicated that by lowering P content,...High purity hot hydrogen charging at high temperature was used to investigate the hydrogen embrittlement (HE) of JBK-75 alloys with different contents of P and Si(Mn). The results indicated that by lowering P content, the size and distribution of gamma' precipitate became more homogeneous and the precipitation of stable phase eta was retarded, thus the hydrogen resistant properties of the alloy was obviously improved; however, when Si(Mn) content was lowered together with P, though the size and density of gamma' were also homogeneous and no eta phase was observed, formation of some micro twin around grain boundaries was found to be detrimental to the hydrogen performance of the alloy, and hydrogen induced loss of area reduction was very high. Therefore, to improve the hydrogen resistant properties of the alloy, P content should be lowered while certain amount of Si(Mn) should be kept.展开更多
A 5 kW CW CO2 gas laser was used to produce NiCrBSi superalloy coatings. Powders were preplaced by plasma-spraying. The microstructure and chemical composition of the coating have been studied by SEM, XRD and HREM. Th...A 5 kW CW CO2 gas laser was used to produce NiCrBSi superalloy coatings. Powders were preplaced by plasma-spraying. The microstructure and chemical composition of the coating have been studied by SEM, XRD and HREM. The results show the coating microstructure is fine dendrites, composed of gamma matrix, gamma' and boride (NiB) eutectic, the lattice parameter of the gamma matrix is 0.3572 nm and there is a metallurgical bonding in interface.展开更多
文摘High purity hot hydrogen charging at high temperature was used to investigate the hydrogen embrittlement (HE) of JBK-75 alloys with different contents of P and Si(Mn). The results indicated that by lowering P content, the size and distribution of gamma' precipitate became more homogeneous and the precipitation of stable phase eta was retarded, thus the hydrogen resistant properties of the alloy was obviously improved; however, when Si(Mn) content was lowered together with P, though the size and density of gamma' were also homogeneous and no eta phase was observed, formation of some micro twin around grain boundaries was found to be detrimental to the hydrogen performance of the alloy, and hydrogen induced loss of area reduction was very high. Therefore, to improve the hydrogen resistant properties of the alloy, P content should be lowered while certain amount of Si(Mn) should be kept.
文摘A 5 kW CW CO2 gas laser was used to produce NiCrBSi superalloy coatings. Powders were preplaced by plasma-spraying. The microstructure and chemical composition of the coating have been studied by SEM, XRD and HREM. The results show the coating microstructure is fine dendrites, composed of gamma matrix, gamma' and boride (NiB) eutectic, the lattice parameter of the gamma matrix is 0.3572 nm and there is a metallurgical bonding in interface.
