Abstract

The elemental, phase, and structural state of Nb–Mo–C alloys with equiatomic metal contents and 15, 20, 25, and 30 at % C are studied after electron-beam zone melting. In the alloy containing 15 at %, a fine microstructure, which is typical of eutectic alloys, forms; as the carbon content increases, primary carbide crystals appear in the alloy structure. The main carbide phase in all alloys is found to be an NbC-based carbide rather than an Nb₂C-based carbide. The component distribution between the phases is studied as a function of the average alloy composition. The results of short-time strength tests of alloy specimens at room temperature and at 1500°C and also their high-temperature bending creep tests are presented. The 100-h creep strength maximum for the alloys is shown to be 200–300 MPa at 1500°C (\(\sigma _{{100}}^{{1500}}\) = 200–300 MPa).

中文翻译：

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碳含量对高温硬质合金铌钼合金组织和力学性能的影响

摘要

在电子束区域熔化后研究了具有等原子金属含量和 15、20、25 和 30 at% C 的 Nb-Mo-C 合金的元素、相和结构状态。在含有 15 at % 的合金中，形成了典型的共晶合金的精细微观结构；随着碳含量的增加，合金结构中出现一次碳化物晶体。发现所有合金中的主要碳化物相是基于NbC的碳化物而不是基于Nb ₂ C的碳化物。研究了相之间的组分分布作为平均合金成分的函数。介绍了合金试样在室温和 1500°C 下的短时强度试验结果，以及它们的高温弯曲蠕变试验结果。合金的 100 小时最大蠕变强度在 1500°C 下显示为 200–300 MPa (\(\sigma _{{100}}^{{1500}}\) = 200–300 MPa)。