摘要
Hot tensile tests were carried out on FeNi36 (Invar alloy) over the temperature range of 850–1150 °C and at strain rates of 0.001–1 s−1. The hot ductility improved by increasing temperature and strain rate. The improvement of hot ductility at high temperatures was attributed to the influence of dynamic recrystallization. On the other hand, increasing strain rate could reduce the time for the propagation of voids and therefore postpone final fracture. The influences of microalloying additions from Al, Zr, Ti and Mg on the hot ductility were investigated by similar hot tensile tests. The results showed that the addition of Al as a microalloying element could harm the hot ductility. It was associated with the increase of the stacking fault energy of the base metal, thereby decreasing the tendency for dynamic recrystallization. In addition, the aluminum oxide particles could act as the preferential sites for cracking. The addition of Zr degraded the hot ductility. It was attributed to increasing the stacking fault energy of the base metal and thereby decreasing the tendency for dynamic recrystallization. The hot ductility was improved by the addition of Ti. The positive effect of Ti was attributed to its effect on tie-up of S in TiS compounds. Magnesium was found as the most effective microalloying addition which could remarkably improve the hot ductility of the base metal. The influence of Mg on reacting with S thereby avoiding the grain boundary weakness was found responsible for the remarkable improvement of hot ductility. By adding 0.003 wt.% Mg the amount of S in the material decreased from 0.0022 to 0.0011 wt.%.
摘要译文
热拉伸试验进行了FeNi36（因瓦合金）超过850-1150℃的温度范围内，并以0.001 s SUP应变率 - SUP 1 SUP。通过增加温度和应变速率的热延展性的改善。的热延展性在高温下的改善是由于动态再结晶的影响。另一方面，增加应变速率可以减少时间为空隙的传播，因此推迟最终断裂。微合金添加剂的选自Al，Zr，Ti和Mg的对热延展性的影响通过类似热拉伸试验研究。结果表明，添加Al作为一种微合金元素可能伤害的热延展性。将其与基体金属的堆垛层错能的增加相关联，从而减少对动态再结晶的倾向。此外，氧化铝颗粒可以作为优先位点裂解。添加Zr的劣化的热延展性。它是由于增加了基体金属的层错能，从而减少对动态再结晶的倾向。热延展性通过加入钛提高。钛的积极作用是由于其对的TiS化合物提携的S的影响。镁被发现的最有效的微合金除了这可能显着地提高了基体金属的热延展性。镁对以S从而避免了晶界反应疲软的影响，发现负责热延展性的显着提高。通过添加0.003％（重量）25的Mg的S中的材料的量减少，从0.0022至0.0011％（重量）25。
S.M. Abbasi[a]; M. Morakabati[a]; R. Mahdavi[a]; A. Momeni[b]. Effect of microalloying additions on the hot ductility of cast FeNi36[J]. Journal of Alloys and Compounds, 2015,639: 602–610