Gigacycle fatigue properties of high-strength steels according to inclusion and ODA sizes
Gigacycle fatigue properties of high-strength steels according to inclusion and ODA sizes
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DOI：
10.1007/s11661-007-9225-3
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发表时间：
2007-08-01
影响因子：
2.8
通讯作者：
Hayaishi, M.
中科院分区：
文献类型：
--
作者：
Furuya, Y.;Hirukawa, H.;Hayaishi, M.
采用20 kHz超声疲劳试验对几种版本的JIS-SCM 440低合金和JIS-SUJ 2轴承钢进行了千兆赫疲劳试验，以阐明夹杂物尺寸和类型与鱼眼断裂性能的关系。测试的样本总数超过200个。大多数试样显示出Al 2 O3或（Cr，Fe）（3）夹杂物引起的鱼眼断口，而TiN夹杂物和基体也在一些试样中引起鱼眼断口。根据这些疲劳试验结果，通过根据鱼眼断裂起点处的夹杂物尺寸对获得的数据点进行重新排序，根据夹杂物尺寸估算10（9）次循环疲劳极限。当夹杂物尺寸小于15 μ m时，估计的疲劳极限显示饱和，而当夹杂物尺寸大于15针时，这些疲劳极限取决于夹杂物尺寸的-1/6次方。认为109次循环疲劳极限的饱和是由光学暗区（ODA）的影响引起的。此外，疲劳极限也取决于夹杂物的类型。在比较Al 2 O3和（Cr，Fe）（3）C夹杂物时，导致疲劳极限差异的关键特征可能是夹杂物和基体之间的结合，即，与Al 2 O3夹杂物不同，（Cr，Fe）（3）C夹杂物与基体紧密结合，尽管这两种夹杂物都是硬型的。
Gigacycle fatigue tests were conducted for several versions of JIS-SCM440 low-alloy and JIS-SUJ2 bearing steels using 20-kHz ultrasonic fatigue testing to elucidate the relationship of the inclusion size and type to fish-eye fracture properties. The total number of tested specimens was over 200. Most of the specimens revealed Al2O3 Or (Cr, Fe)(3) inclusion-originating types of fish-eye fractures, while TIN inclusions and the matrix also caused fish-eye fractures in some specimens. Based on these fatigue test results, 10(9)-cycle fatigue limits were estimated according to inclusion size by resorting the obtained data points according to their inclusion sizes at the fish-eye fracture origin. The estimated fatigue limits revealed saturation when the inclusion sizes were smaller than 15 mu m, while those fatigue limits depended on the inclusion sizes to the -1/6th power in the case of inclusions above 15 pin in size. The saturation of the 109-cycle fatigue limits was considered to be caused by the effects of the optically dark areas (ODAs). Moreover, the fatigue limits also depended on inclusion type. In comparing the Al2O3 and (Cr, Fe)(3)C inclusions, the key features causing the difference in the fatigue limits were likely to be bonding between the inclusion and the matrix, i.e., the (Cr, Fe)(3)C inclusions were tightly bonded to the matrix, unlike the Al2O3 inclusions, although both inclusions were of the hard type.