王衣孙锋董显平张澜庭单爱党
金属学报
doi:DOI:10.3724/SP.J.1037.2009.00515
利用热力学计算软件JMatPro和相应的镍基高温合金数据库, 研究了U720Li合金以及在此基础上研发的新型Ni-Co基高温合金的化学成分对平衡相的析出行为、加工性能和γ/γ'晶格错配度的影响. 结果表明: Ti/Al值(原子比)的增加提高了合金中γ/γ'相的晶格错配度, γ'析出相的含量随Ti+Al含量(原子分数)的增加而增加. 因此, 增加Ti/Al值和Ti+Al含量能提高合金的高温强度. Co含量的升高可以拓宽合金的加工窗口, 改善合金的加工能力, 并且还可以增加合金γ/γ'相的晶格错配度, 提高合金错配强化的效果. 同时, Ti/Al值的增加促进合金中η相析出, 而Co含量的增加具有抑制η相的效果. 因此, 在 Co含量较高的Ni-Co基高温合金中, 适当提高Ti含量, 增加Ti/Al值对提高合金高温强度有利.
关键词:
Ni-Co基高温合金
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thermodynamic calculation
,
precipitation phase
,
mismatch
蒯春光
,
彭志方
金属学报
利用Thermo-Calc软件计算了高Cr铁素体耐热钢T/P91在450-1200 ℃区间的
平衡相成分及其含量. 引入合金相元素分配量的概念, 研究了钢中Cr, Mo, Fe,
V, Nb, C和N等主要元素随着温度变化在各平衡相中的分配特征、相稳定性、化
学组成及其演化规律. 结果表明, 利用相元素分配量随温度变化的特征, 便于揭
示不同温度区间M23C6及MX相的稳定性, 合理确定不同MX相的亚类型及
M和X的构成及演化规律. 此外, 有助于了解基体相含碳量的变化对
M23C6和MX相的影响.
关键词:
耐热钢T/P91
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Thermo-Calc
,
thermodynamic calculation
,
elemental partitioning fraction
S.Q. Zhao
,
Y. Jiang
,
J.X. Dong
,
null
,
null
,
null
金属学报(英文版)
A novel nickel-based superalloy INCONEL 740 was under development for application in ultra-supercritical superheater tubers above 750℃. The precipitation behaviors of ?浊 phase and ?酌' particles of the alloy were investigated through experimental study and phase computation. Experimental results showed that ?浊 phase formed a Widmanst?覿tten pattern structure following long-term exposure at elevated temperatures and that the coarsening of ?酌' particle follows a cube rate law: 3 ∝ t. Thermodynamic calculation results showed that Al and Ti had an important effect on the precipitation behavior of ?酌' and ?浊 phases. Two suggested novel modified alloys, wherein the Al and Ti contents were modified, were designed and melted for the experimental study. The preliminary results indicated that the modified alloys exhibited higher structural stability following long-term exposure at 750℃ till 5000h.
关键词:
superalloy
,
null
,
null
,
null
Yanzhao LUO
金属学报(英文版)
Based on thermodynamics calculation, the results of the formation temperature of MnS inclusions of non-quenched and tempered steel during heating process were discussed. It is shown that while the solid fraction is 0.9, MnS inclusions began to precipitate in the final stage of solidification. The solidification process of 49MnVS3 non-quenched and tempered steel during heating has been observed in situ using a confocal scanning laser microscope (CSLM), which agrees well with the thermodynamics calculation. MnS particles were coarsening during heating process, which would reduce the pinning effect on the austenite grain boundaries and bring about the sudden growth of some austenite grains in this stage.
关键词:
Confocal laser scanning microscopy
LI Lin T.Y.Hsu Shandong Polytechnic University
,
China.
材料科学技术（英）
Based on the experimental result that Cr and C segregated on the prior grain boundaries of austenite in overheated steels,causing the inheritance of fracture mode after re-austeni- tization,a thermodynamic analysis is conducted through the calculation of equilibrium segregation amount of Cr and C in grain boundary at 860 and 1050℃ and the segregation kinetics of Cr is also calculated.Thermodynamic calculation gives an evidence that the segregation of Cr and C at grain boundaries may be regarded as one of the mechanisms of the fracture inheritance in overheated steels.
关键词:
fracture inheritance
,
null
,
null
,
null
韩国民
,
韩志强
,
Alan A.Luo
,
Anil K.Sachdev
,
柳百成
金属学报
doi:10.3724/SP.J.1037.2012.00531
基于KKS相场模型模拟了Mg-Al合金Mg17Al12单个连续析出相的形貌演化.相场模型中,各相自由能及化学势由Thermo-Calc热力学计算软件计算.构造各向异性函数时考虑了界面能各向异性的影响,基于Khachaturyan微观弹性应变能理论考虑了微观弹性应变能的影响.结果表明:仅考虑界面能各向异性不考虑微观弹性应变能,析出相呈板条状形貌;仅考虑微观弹性应变能不考虑界面能各向异性,析出相呈菱形,综合考虑界面能各向异性和微观弹性应变能,析出相呈板条状形貌,端部呈平行四边形,此形貌特征与实验观察结果吻合;界面能各向异性决定析出相的板条状形貌特征,微观弹性应变能导致端部产生平行四边形特征.
关键词:
Mg-Al合金
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连续析出相
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形貌演化
,
热力学计算
,
界面能各向异性
,
微观弹性应变能
,
相场模型
CHEN Shengqi ZHOU Yanchun XIA Fei ** Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China+ To whom correspondence should be addressed.
材料科学技术（英）
The stability of the phases in equilibrium is calculated and discussed in order to analyse and predict the reactions in SiC and Si_3N_4 whisker formation.Equilibria among SiC,Si_3N_4,Si_2N_2O,SiO_2 and the gas phase are evaluated at different C activity,N_2 pressure,and temperature.According to the phase stability diagrams,Si_3N_4 whisker was formed with the increase of N_2 pressure and decrease of C activity;SiC whisker was stable with the increase of C activity and decrease of N_2 pressure.In order to control the impure phases during the whisker formation,O_2 partial pressure is the most important factor.
关键词:
whisker
,
null
,
null
J.X.Dong
,
M.C.Zhang
,
Y.P.Zeng
,
X.S.Xie
金属学报(英文版)
The freckle formation and their phase characterization in freckle areas were investigated by means of microstructure analysis approaches and a thermodynamic equilibrium phase calculation method in a Ni-Cr-Mo-Fe-W alloy. These results show that in freckle areas a large number of M6 C, u and P phases precipitate in grain boundaries even within grain due to the enrichment and segregation of Mo and C during solidification, which results in small grains in freckle areas. Equilibrium phase and liquid segregation calculation can give an reasonable interpretation of the freckle feature for this alloy.
关键词:
freckle
,
null
,
null
黄运红
,
张义文
,
王福明
,
李长荣
,
程慧静
材料热处理学报
为消除粉末冶金高温合金FGH4097中存在的原始颗粒边界（PPB）,采用Thermo-Calc热力学计算软件对FGH4097合金系进行热力学计算,并进行相应的组织观察与能谱分析,重点研究了铪（Hf）在FGH4097合金中的分布规律以及Hf对析出相的影响,特别是分析了Hf对合金中PPB的影响规律。结果表明,FGH4097合金中Hf主要存在于MC、MB2和γ＇相中,Hf能促进MC相和γ＇相的析出,有效地抑制M6C和M23C6型碳化物的形成。Hf质量分数为0.30%时消除了FGH4097合金中的PPB。
关键词:
铪元素
,
FGH4097合金
,
原始颗粒边界(PPB)
,
热力学计算
,
平衡相
程晓农
,
王荣荣
,
李冬升
,
戴起勋
,
黄燕
,
刘瑜
,
陶亚平
材料热处理学报
利用X射线衍射仪（XRD）、扫描电镜（SEM）和能谱仪（EDS）等,对800H合金高温氧化膜的增厚动力学、形貌及氧化物组成进行了分析。结果表明,700和800℃下形成的氧化膜相近,由（Cr,Fe）2O3和Mn-Cr氧化物组成;900℃时的氧化膜急剧增厚,里层依然是Cr2O3,中间层则是Cr-Fe-Mn氧化物,外层为富Ti的氧化物。通过热力学和动力学计算,提出了800H合金氧化膜形成的模型,发现TiN的存在改变了氧化膜的结构。
关键词:
800H合金
,
高温氧化
,
氧化膜
,
热力学计算
