于彦冲
,
陈伟庆
,
郑宏光
稀有金属材料与工程
通过Gleeble-3800热模拟实验机和微机控制万能材料试验机对Fe-36Ni因瓦合金的热塑性进行了研究.结果表明:在1050～1200℃,由于动态再结晶出现,合金展现出了良好的热塑性,这说明在热加工过程中,终轧温度不应低于1050℃.在800～1000℃时,Fe-36Ni因瓦合金热塑性较差,表现为脆性断裂,晶界滑移是其主要断裂机制.经氧化后,合金基体产生严重的内氧化,内氧化层由晶间氧化区和晶内氧化区组成.压缩试验表明,在变形过程中,晶间氧化会导致裂纹的产生,进而显著恶化合金的热塑性.
关键词:
Fe-36Ni因瓦合金
,
热塑性
,
晶界滑移
,
动态再结晶
,
晶间氧化
M. Yamamoto and T. Ogata (Central Research Institute of Electric Power Industry
,
2-11-1
,
Iwado Kita
,
Komae-shi
,
Tokyo 201-8511
,
Japan)
金属学报(英文版)
In order to investigate creep-fatigue life characteristics of Inconel 738LC, fatigue and creep-fatigue tests were carried out at 850℃. Significant life reduction to 30% to 50% of normal fatigue life, occurred when a strain hold period was introduced at the minimum compressive strain. Test results showed that the degree of life reduction did not depend on the length of hold time. To clarify the creep-fatigue damage mechanisms under creep-fatigue loading, in-situ SEM observations were carried out during the tests. In the tensile strain hold test, multi-site grain boundary cracking was observed from the beginning of the test. On the other hand, only a single main crack was observed in the compressive strain hold test. The crack propagated in an intergranular manner and it was different from the features observed under cyclic fatigue conditions. Through detailed observation, it was found that grain boundary sliding damage occured at most surface grain boundaries.
关键词:
superalloy
,
null
,
null
