Effect of prior oxidation on high cycle fatigue performance of RR1000 and role of oxidation in fatigue crack initiation
Effect of prior oxidation on high cycle fatigue performance of RR1000 and role of oxidation in fatigue crack initiation
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DOI：
10.1179/0960340914z.00000000064
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发表时间：
2015-01
影响因子：
1.3
通讯作者：
S. Cruchley;M. P. Taylor;H. Y. Li;H. Evans;P. Bowen;D. J. Child;M. Hardy
中科院分区：
文献类型：
--
作者：
S. Cruchley;M. P. Taylor;H. Y. Li;H. Evans;P. Bowen;D. J. Child;M. Hardy
在700°C、R比为0·1、预氧化时间为100和2000 h的条件下，研究了预氧化对粗晶镍基高温合金RR 1000室温疲劳寿命的影响。这些预暴露产生广泛的氧化损伤。预氧化试样的室温高周疲劳寿命已被比较，作为收到的标本。在800 MPa的最大施加应力下，在预氧化试样中观察到显著的疲劳寿命不足。这是伴随着观察到的显着开裂的外部氧化铬规模和晶粒间的内部氧化物的区域内的最大应力。氧化物的优先开裂可能导致早期裂纹萌生，从而降低总疲劳寿命。
Abstract The effect of prior oxidation on the room temperature fatigue life of coarse grained Ni based superalloy, RR1000 has been performed at an R ratio of 0·1 with two pre-oxidation times: 100 and 2000 h at 700°C. These pre-exposures produce extensive oxidation damage. The room temperature high cycle fatigue life of the pre-oxidised specimens has been compared to as received specimens. At a maximum applied stress of 800 MPa a significant fatigue life deficit is observed in the pre-oxidised testpieces. This is accompanied with the observations of significant cracking of the external chromia scale and the intergranular internal oxides within the area of maximum stress. Preferential cracking of oxides may lead to early crack initiation and consequently a reduction in total fatigue life.