论文部分内容阅读
本文研究了不含钴、低钴(3～5％)、高钴(10～20％)含量,对Ni-Cr-W-Mo系固溶强化镍基高温合金性能与组织的影响。从而探讨钴的合金化作用,以及节钴的潜力。研究结果表明,钴的含量在0到20％之间变化时,室温和高温抗张强度变化很小。一般来说,随钴含量的增加,合金的塑性提高。明显地提高了合金的冲击强度和816℃～12.6公斤/毫米~2下的持久寿命,特别是高钴含量对合金持久寿命的改善更为显著。相分析和微观分析的结果表明,钴本身的固溶强化作用是弱的,而对碳化物的析出数量与形态有较大的影响。随含钴量的增加,析出碳化物数量减少,从而增加了Cr、Mo、W等固溶强化元素在合金基体中的固溶量,这对提高合金的高温蠕变抗力,改善合金的长时组织稳定性是有利的。此外,在合金晶界上析出的碳化物M_(23)C_6骨骼状群团,随钴含量的增加,显著减少。而这种晶界碳化物在高温拉伸时,往往成为断裂源。研究结果表明,低于15％的Co含量,对合金的强度效果是不明显的,因此,在0～15％Co含量范围,节Co的余地较大。
In this paper, the effects of cobalt-free, low-cobalt (3-5%) and high-cobalt (10-20%) content on the microstructure and properties of Ni-Cr-W-Mo solid solution strengthened Ni-based superalloys were investigated. To explore the alloying of cobalt, as well as the potential of cobalt. The results show that when the content of cobalt varies from 0 to 20%, the tensile strength at room temperature and high temperature changes little. In general, with the increase of cobalt content, the plasticity of the alloy increases. The impact strength of the alloy and the durable life at 816 ℃ ~ 12.6 kg / mm ~ 2 obviously increase obviously, especially the high cobalt content improves the durable life of the alloy more significantly. The results of phase analysis and microscopic analysis show that the solid solution strengthening effect of cobalt itself is weak, but it has a great influence on the amount and shape of carbide precipitation. With the increase of cobalt content, the amount of precipitated carbide decreases, which increases the solid solution amount of solid solution strengthening elements such as Cr, Mo, W in the alloy matrix, which improves the creep resistance of the alloy at high temperature and improves the long time of the alloy Tissue stability is beneficial. In addition, the skeleton of M_ (23) C_6 carbides precipitated on the grain boundaries of the alloy decreases with the increase of cobalt content. And this kind of grain boundary carbide often becomes the source of fracture when stretched at high temperature. The results show that less than 15% Co content, the effect of the strength of the alloy is not obvious, therefore, in the range of 0 ~ 15% Co, section Co more room.