Important Factors Affecting the Stability of Substructure in Heat-resistant Materials

影响耐热材料亚结构稳定性的重要因素

基本信息

批准号：
15560602
负责人：
ENDO Takao
金额：
$ 2.11万
依托单位：
National University Corporation Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

In the project term, we confirmed that the growth of subgrain during creep (i.e., degradation of substructure) and the Ostwald ripening observed in a heat resistant steel, Al-Cu alloys and a commercial magnesium alloy were all strain dependent notwithstanding that attention was not paid to the effect of strain on the structural degradation so far. Furthermore, the critical stress necessary for subgrain boundary to escape from pinning of precipitates was examined. The results showed that the subrain size remained unchanged in a stress range below the critical stress while it begins to increase in a stress range above the critical stress. On the theoretical basis, the critical stress is expected to be independent of testing temperature, however, the measured critical stress was temperature-dependent. In order to clear the reason for this temperature dependence, the average size and inter-particle spacing of precipitates were measured as a function of testing temperature. The experimental … More results showed that the inter-particle spacing increased with increase in testing temperature because particle coarsening occurred during heating to testing temperature before stress application. The analysis showed that the temperature dependence of critical stress was only apparent. The magnitude of critical stress was almost equal to the theoretical one calculated from the model proposed in Mater.Trans.44(2003),239-246.Since the structural degradation of T91 steel is associated with migration of subboundary, we can view that the structural degradation was promoted by dislocation motion (plastic strain). Actually, the origin of structural degradation of this type is seemingly different from the strain enhanced Ostwald ripening, however, we can view that the origin of both phenomena is the same because the growth of precipitates which hinder the sub-boundary migration can also be assisted by the motion of subboundary.Generally, many heat-resistant materials contain solute atoms with a relatively large size misfit. This is because solutes of this type are effective to strengthen their matrix, however, these solutes are liable to introduce the solute transport assisted by dislocation motion, and eventually lead to strain-enhanced growth of precipitates. So far, solutes with a relatively large size misfit were preferably added to heat-resistant materials to strengthen their matrix, however, these elements are susceptible to strain enhanced coarsening of precipitates. Strain enhanced structural degradation was not taken into account so far in alloy designing, however, it is important to re-consider the alloying elements taking into account the scavenging effect which causes the strain enhanced coarsening of precipitates. Less

在项目术语中，我们证实了蠕变过程中亚晶粒的生长（即，子结构的降解）和在耐热钢，al-CU合金和商业磁合金中观察到的Ostwald成熟，但均取决于菌株，尽管注意力并未引起对结构降解的效果的关注。此外，检查了亚晶界边界从沉淀物钉钉中逃脱所需的临界应力。结果表明，在低于临界应力的压力范围内，子污垢的大小保持不变，而在临界应力以上的应力范围内开始增加。在理论的基础上，预计临界应力与测试温度无关，但是，测得的临界应力依赖于温度。为了清除这种温度依赖性的原因，测量了沉淀物的平均大小和粒子间间距是测试温度的函数。实验……更多的结果表明，粒子间间距随着测试温度的升高而增加，因为在加热期间，在施加压力之前，在加热到测试温度的过程中发生了颗粒。分析表明，临界应力的温度依赖性仅显而易见。临界应力的幅度几乎等于从母体中提出的模型中计算出的理论。44（2003），239-246。由于T91钢的结构降解与子结构的迁移有关，我们可以观察到通过脱位运动促进结构降解（塑性应变）。实际上，这种类型的结构降解的起源似乎与菌株的增强菌株有所不同，但是，我们可以观察到两种现象的起源都是相同的，因为造成的降水的生长可以通过副群的运动来帮助，从而有助于sipboundary的运动。基准，许多耐热的材料都含有较大的尺寸，均较大尺寸。这是因为这种类型的溶剂可有效增强其基质，但是，这些固体有可能引入脱位运动辅助的固体运输，并最终导致贵重物的应变增强。到目前为止，优选将具有相对尺寸的型级的溶剂添加到耐热材料中以增强其基质，但是，这些元素易于过滤增强的贵重物质。迄今为止，在合金设计中尚未考虑应变结构降解，但是，重要的是要考虑到造成珍贵的菌株的清除效果，重新考虑合金元素。较少的

项目成果

期刊论文数量（28）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Change in Vickers Hardness and Substructure during Creep of a Mod.9Cr-1 Mo Steel

Mod.9Cr-1 Mo钢蠕变过程中维氏硬度和亚结构的变化

DOI：
发表时间：
2003
期刊：
Mater.Trans. 44
影响因子：
0
作者：
Takao Endo;F.Masuyama;K-S.Park
通讯作者：
K-S.Park

Change in Vickers Hardness and Substructure during Creep of a Mod.9 Cr-1 Mo Steel

Mod.9 Cr-1 Mo 钢蠕变过程中维氏硬度和亚结构的变化

DOI：
发表时间：
2003
期刊：
Mater.Trans. 44[2]
影响因子：
0
作者：
Takao Endo;Fujimitsu Masuyama;Kyu-Seop Park
通讯作者：
Kyu-Seop Park

Accelerated coarsening of precipitates in crept Al-Cu alloys

DOI：
10.1016/j.msea.2004.01.131
发表时间：
2004-12-15
期刊：
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
影响因子：
6.4
作者：
Nakajima, T;Takeda, M;Endo, T
通讯作者：
Endo, T

T.Nakajima, S.Spigarelli, E.Evangelista, T.Endo: "Strain Enhanced Growth of Precipitates during Creep of T91"Materials Trans.. 44 No.9. 1802-1808 (2003)

T.Nakajima、S.Spigarelli、E.Evangelista、T.Endo：“T91 蠕变期间沉淀物的应变增强生长”Materials Trans.. 44 No.9。