Guangwei HAN
,
Di FENG
,
Ming YIN
,
Wujun YE and Heli LUO(Dept. of Superalloys
,
Central Iron and Steel Research Institute
,
Beijing 100081
,
China)
材料科学技术（英文）
The recrystallization behaviour of cold drawn MP159 alloy was investigated by optical and TEM examinations. It is found that the platelet ε phase in the MP alloy inhibits the recrystallization,and this effect makes the MP159 alloy with high recrystallization temperature of about 920℃.This inhibition mainly comes from the increasing of the interfacial energy, which results from the change of the coherent interfaces of (0001)hcp//(111)fcc into the incoherent interfaces when the recrystallizing grain fronts bypass the platelet ε martensite. The increasing of the interfacial energy also causes the dissolution of a few segments on the ε martensite platelets, which decreases the strength of the MP alloy
关键词:
杨金瑞
,
余尚先
,
顾江楠
高分子材料科学与工程
通过对resol(羟甲基酚化合物和低分子量羟甲基酚树脂)DEPT135图谱的分析讨论,得到一系列计算resol微细结构参数的经验公式.根据DEPT135图谱可判断是否发生缩聚反应,根据经验公式可计算酚单体各个活性点参与反应百分率或酚羟基导入率、不同类型缩聚所占百分率及低分子量羟甲基酚树脂的平均核体数.
关键词:
羟甲基酚化合物
,
羟甲基酚树脂
,
DEPT135
,
结构参数
Materials at High Temperatures
Two different ways of combining nitrogen in virgin and revert superalloy have been identified. The source of nitrogen in revert superalloy has been ascertained. It is found that nitrogen in scraps of virgin superalloy undergoes a transition from CrN to TiN when these scraps are remelted in VIM furnace. High nitrogen content in revert superalloys causes microporosity formation, that greatly deteriorates tensile and stress rupture properties of superalloys.
关键词:
nitrogen;revert superalloy;microporosity
Y.F.Gu
,
Y.Yamabe-Mitarai
,
C.Huang
,
H.Harada
金属学报(英文版)
It was proposed that a new class of alloys based on platinum group metals (PGMs) were calle drefractory superalloys. These refractory superalloys have an fcc and L12 coherent two-phase structure (similar to that of Ni-based superalloys), high melting temperatures and good potential as structural materials used at temperatures up to 1800℃. Our recent results on the microstructure evolution, deformation and fracture behavior of some of these refracotry superaUoys, especial lr- and Rh-base refractory superalloys were reported.
关键词:
platinum group metals
,
null
,
null
Z. Li
,
S.F. Tian
,
X.G. Zhao
,
Z.K. Liang
,
L.P. Ren
,
G.F.Mi and M.G. Yan(Bejing Institute of Aeronautical Materials
,
Beijing 100095
,
China Manuscript received 26 August 1996)
金属学报(英文版)
In this paper,part of the research and development work in the field of spray formed superalloys at BIAM of China is briefly summarized. With an experimental spray forming facility,whose melting capacity is suitable for making disk and columnar shaped integral-dense and clean Ni-base superalloy preforms with low oxygen content,fine grain, uniform chemistry and improved forgeability, a series of Ni-base superalloys have been spray atomized and deposited, among which three alloys have been chosen for microstructural and mechanical properties evaluation.
关键词:
:spray forming
,
null
,
null
材料科学技术（英文）
Tubular products made of superalloys and titanium alloys usually work in high temperature environment and applied heavy loading. Hot extrusion is the best technology to form tubular billets with fine microstructures and good mechanical properties. Lubrication is one of the key techniques in hot extrusion, glass lubricants are most suitable for hot extrusion. Lubrication technique in hot extrusion is dealt with in this paper, the lubrication principle of hot tube extrusion is presented. Experiments of glass lubricated backward tube extrusion of titanium alloys and forward tube extrusion of superalloys are also discussed.
关键词:
MA Peili YUAN Ying ZHONG Zengyong Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China MA Peili Senior Engineer
,
Lab.of Superalloy
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing 100081
,
China
金属学报(英文版)
By adding small amount of Mg to the wrought superalloys,the steady stage of creep,and es- pecially the tertiary stage of creep are prolonged.Also,the steady creep rate is decreased within the range of low strain rates.At higher strain rates,however,the effect of Mg on creep rate vanishes.This may be attributed to the Mg dissolution in the matrix.A mechanism of the effects of Mg addition on creep behaviors is proposed.
关键词:
Mg microalloying
,
null
,
null
,
null
Acta Metallurgica Et Materialia
In this work, the hydrogen permeation and diffusion in three iron-base superalloys, JBK-75, Incoloy903 and GH35A, were investigated. A gaseous permeation technique was employed to measure the hydrogen permeabilities and diffusivities of specimens with different heat treatments for a given alloy over the temperature range of 210-430-degrees-C. The effects of strengthening phase gamma' on the hydrogen permeation and diffusion in the alloys were examined. The results showed that the dependences of the hydrogen permeabilities and diffusivities in various alloys on the temperature obeyed Arrhenius relationship over the test temperature range and that the hydrogen permeation behavior in these alloys was essentially independent of their heat-treated conditions, i.e. which was not significantly affected by gamma' precipitates in the alloys. The hydrogen permeation parameters of the iron-base superalloys were approximately consistent with those of the austenitic stainless steels. The hydrogen transport in these alloys with fc.c. structure was generally controlled only by the lattice diffusion of hydrogen.
关键词:
microstructure;behavior;alloys
材料科学技术（英文）
It is well known that carbides at grain boundaries play an important role in affecting mechanical properties of nickel based superalloys. In order to deeply understand the relationship between grain boundary structures and properties, in this work, we have investigated the microstructure of grain boundaries with different misorientation angles in bicrystals of nickel based superalloys. It is found that the bicrystals with smaller misorientation angles contain denser M23C6 but sparse MC particles at grain boundaries, and this kind of bicrystals presents longer stress rupture lives. It was observed that MC carbides were decorated by M23C6 and M6C particles at grain boundaries. The formation of these carbide particles, therefore, is likely due to the local fluctuation of chemical composition around MC carbides. In addition, the orientation relationships between MC carbides and gamma/gamma' matrix were also determined.
关键词:
Electron microscopy;Ni based superalloys;Grain boundaries;Orientation;relationship;primary mc carbide;creep-properties;sx-superalloys;decomposition;rupture;rr2072
