摘要
3J40是一种镍基弹性合金，具有高强度、高硬度、高弹性、耐腐蚀和无磁性等特点，主要应用于制作航空、航海、高炮等领域使用的轴承、轴尖。研究中发现该合金时效热处理后硬度不均匀，性能不稳定，而且空冷与炉冷之间硬度差异大。原有的研究主要集中于夹杂物分布、大小、形态等方面，旨在提高合金塑性，进一步改善其热加工性；在合金性能与组织方面的工作也倾注于传统的Ni3Al-γ’相研究；经文献检索尚未见有关3J40合金α-Cr相强化机理方面的报道。本项目经过热力学相平衡计算得到合金热处理后可能析出平衡相，研究了温度、时间和冷速等时效热处理工艺对3J40合金性能的影响，分析了不同热处理工艺下合金组织，特别是α-Cr相的形貌、大小、数量，探讨了合金强化机理。结果表明，合金时效后组织为奥氏体γ相基体＋强化相Ni3Al-γ’相和颗粒状、片层状α—Cr相，而强化效果主要来自于片层状α—Cr相的贡献。
3J40 alloy is widely used as bears and conical pivots in the fields like navigation, aviation and antiaircraft gun due to its excellent properties of elasticity, strength, hardness, resistant corrosion, nonmagnetic and so on. In this paper, the effect of α-Cr phase on the strengthen mechanism in 3J40 alloy has been investigated. By thermodynamic phase equilibrium calculation, the possible precipitated phase has been predicted. Relationship between the mechanical properties and the ageing heat treatment parameters like ageing temperature, ageing time and cooling rate has been studied. The particles size, morphology and distribution of the precipitated α-Cr phase have been observed through OM （optic microscope） and SEM （scanning electron microscope）. The results show that the microstructures of the ageing 3J40 alloy are composed of γ-based phase, precipitated γ phase, phase （Ni3Al）, and α-Cr phase in granular and laminar. And the main contribution for the strengthen mechanism may be associated with the α-Cr phase laminar.
出处
《金属材料研究》
2011年第3期1-8,共8页
Research on Metallic Materials
