郭守仁
,
卢德忠
,
郭建亭
,
吴晰
金属学报
本文研究了GH35A合金在650—750℃,100—10000h时效过程中性能和组织的变化。结果表明,合金室温拉伸强度基本不受时效温度和时间的影响,而室温塑性、韧性及700℃持久寿命在时效至某一时间后开始降低,但下降速度缓慢,直到10000h仍有较高的水平。同时,随时效温度提高,性能降低的开始时间缩短。合金性能的变化主要取决于σ相析出的时间、形态、分布以及σ相的特征。
关键词:
高温合金
,
aging
,
mechanical property
,
σ-phase
,
γ′-phase
吴惕言
,
吴起白
,
RIQUIERY.
金属学报
研究了铁素体(F)-奥氏体(A)双相不锈钢在600—1100℃范围内的力学性能,其韧性-温度曲线在800-900℃之间有一极小值。阐述了σ相析出动力学及其对材料力学性能的影响,σ相严重损害合金塑性,其影响程度随σ相含量的增加而增高,并与试验温度有极大的关系,1000℃时σ相对拉伸性能影响消失。
关键词:
双相不锈钢;σ相
,
σ-phase
宾远红
,
李培芬
,
李志铮
,
范兆永
材料热处理学报
采用金相显微镜、扫描电镜、能谱分析、室温冲击等方法,研究了不同固溶温度下2205双相不锈钢σ相析出行为以及对冲击性能的影响,用于指导双相不锈钢的热加工工艺.结果表明:在750～ 900℃时,有σ相析出,析出位置集中在α/γ相界上.随着固溶温度的升高,σ相析出尺寸变大,析出量呈先增多再减少,σ相析出的鼻尖温度范围在850 ～ 900℃之间.σ相析出使2205双相不锈钢冲击韧性急剧下降,随固溶温度的升高,冲击韧性持续降低,900℃时冲击韧性最差,仅有38 J,因此双相不锈钢在热加工过程中应尽量避免在σ相析出温度范围内停留.
关键词:
双相不锈钢
,
固溶处理
,
σ相
,
冲击韧性
王冬
,
邹德宁
,
韩英
,
程宝
材料热处理学报
通过JMatPro软件,计算预测254SMo超级奥氏体不锈钢(SASS)和2507超级双相不锈钢(SDSS)中σ相的热力学析出条件,并制定了不同的热处理制度;同时借助光学显微镜、扫描电镜等手段分析研究了经不同温度时效不同时间后σ析出相的形态及析出机理.结果表明:254SMo SASS在1020℃不同时效时间下,在晶界上析出富含Cr、Mo和低Ni的σ相.随着时效时间增加,σ相数量增多、尺寸增大,且呈短棒状、长条状和胞状等形态,并按照γ→σ方式析出;2507 SDSS在950℃不同时效时间下,在α/γ界面和α/α晶界处析出富含Cr、Mo和更低水平Ni的σ相.随着时效时间增加,σ相数量增多,向铁素体内部长大并最终呈网状分布在奥氏体基体上,且伴有二次奥氏体(γ2)生成,其是按照α→σ+γ2方式析出.
关键词:
254SMo超级奥氏体不锈钢
,
2507超级双相不锈钢
,
σ相
,
热力学计算
LIU Shicheng
,
Dalian Railway Insitute
,
Dalian
,
ChinaHamaguchi Yoshikazu
,
Kuwano Hisashi
,
Muroran Institute of Technology
,
Muroran
,
Japan
金属学报(英文版)
The stable ranges concerning the composition and temperature have been experimentally de- termined for the intermetallic compounds in system Fe-Cr-Mo at high-temperatures. The isothermal section of the Fe-Cr-Mo ternary phase diagram at 1250℃ and the formation re- actions for the intermetallic compounds, which are different in part from those shown in the literature, have been proposed.
关键词:
Fe-Cr-Mo system
,
null
,
null
,
null
,
null
GUO Shouren LU Dezhong GUO Jianting Institute of Metal Research
,
Academia
,
Shenyang
,
ChinaWU Xi Fushun Steel Works
,
Fushun
,
China Associate Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The mechanical properties and microstructure of an Fe-base superalloy GH35A have been examined after aging at 650—750℃ for 100—10000 h.The tensile strength of the alloy changes no more with aging temperature and the time at room temperature,but the ductility and impact toughness at room temperature,as well as the stress-rupture life up to 700℃ de- crease slowly during aging up to 10000 h The initiation time to worsen its properties becomes shorter as the aging temperature rises.The variation of the mechanical properties of the alloy was found mainly depending on the formation,morphology,distribution and characteristic of the σ-phase precipitation.
关键词:
superalloy
,
null
,
null
,
null
,
null
NI Kequan CHEN Guoliang ZHU Ping XIA Haiping ** Dept.of Materials Science & Engineering
,
University of Science and Technology Beijing
,
Beijing
,
100083
,
China*** Shenzhen Jinyuan Stainless Steel Co.Ltd.
,
Shenzhen.518067
,
China+ To whom correspondence should be a
材料科学技术（英文）
Using the calculation of thermodynamic equilibria in multicomponent systems,two ternary phase diagrams,Ni-Cr-Mo and Ni-Cr-Co,have been calculated by optimizing the Gibbs free ener- gies with respect to phase diagrams and thermodynamic data.On the basis of this calcula- tion,the occurrence of σ-phase in the residual solid solution of commercial Ni-base superalloys, IN-713C and U-700,has been predicted.The re- sults show that the calculation of phase equilibria is successful in the prediction of the occurrence of the σ-phase.
关键词:
thermodynamics
,
null
,
null
,
null
LIU Yuesheng ZHAO Xianguo LIU Zhizhong XIE Xishan Beijing Institute of Aeronautical Materials
,
100095
,
China. University of Science and Technology Beijing
,
100083
,
China.To whom correspondence should be addressed.
材料科学技术（英文）
On the basis of an investigation on σ phase in Ni-base cast superalloy K24 and the results about σ phase in other Ni-base superalloys,an embrittl- ing mechanism and a softening mechanism,by which platelike σ phase weakens the Ni-base superalloys,have been proposed.It is considered that the platelike morphology and the habit precipi- tation along{111}of σ phase are necessary condi- tions for both mechanisms.The embrittling mecha- nism is dominant at room temperature and high strain rate,and the softening mechanism is domi- nant at high temperature and low strain rate.Ac- cording to the idea of the softening mechanism and the analyses of σ phase and alloy compositions,it is considered that Nb,Mo and W in the alloys may be resistant to the detrimental effect of σ phase on the stress-rupture properties of the alloys.
关键词:
Ni-base superalloys
,
null
,
null
