材料期刊网

对不同碳含量的Nimonic 105合金进行了室温和750℃高温力学性能测试,结合热力学模拟计算和相分析研究了碳含量对Nimonic 105合金的力学性能、组织与析出相的影响.结果表明,随着合金中碳化物析出量的增加,Nimonic 105合金发生脆性断裂的倾向增大;适当降低碳含量可有效减少MC相及碳化物的析出量,确保在后续热处理时析出较多的y'相和更多的Mo元素固溶于基体中,改善合金的沉淀强化效果和固溶强化效果,同时使晶粒尺寸增加,从而使合金的冲击韧性和高温塑性均显著提高的同时,高温强度也略有提高.由热力学模拟计算结果可知,Nimonic 105合金的碳质量分数不宜低于0.04％,以防止σ相的析出,同时也可防止μ相过多析出.Nimonic 105合金中碳质量分数最好控制在0.05％～0.10％.

Mechanical properties tests were carried out at room temperature and 750 ℃ for Nimonic 105 alloy with different carbon contents,combining with thermodynamic simulation and phase analysis,to investigate the influence of carbon content on the mechanical properties,microstructure and precipitated phases of the Nimonic 105 alloy.The results showed that with the increase in precipitated carbides the Nimonic 105 alloy exhibited still greater tendency towards brittle fracture,and that an appropriate decrease in the carbon content could effectively reduce precipitation of both MC phase and carbides,and ensure a larger amount of γ'phase being precipitated and still more molybdenum element being dissolved in the matrix during the subsequent heat treatment,which would improve precipitation strengthening and solution strengthening effects of the alloy,and increase the grain size,thus causing the alloy to exhibit higher both the impact toughness and high-temperature plasticity as well as slightly better high-temperature strength.From the thermodynamic simulation data it was seen that the carbon content by mass in the Nimonic 105 alloy should not be less than 0.04％ in order to prevent both σ phase and excessive μ phase from precipitating in the alloy.The carbon contents by mass ranging from 0.05％ to 0.10％ are preferable to the others for the Nimonic 105 alloy.