Effect of Low Temperature Gas Nitriding and Low Temperature Gas Carburizing on High Cycle Fatigue Property in SUS316L
Effect of Low Temperature Gas Nitriding and Low Temperature Gas Carburizing on High Cycle Fatigue Property in SUS316L
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低温气体渗氮和低温气体渗碳对SUS316L高循环疲劳性能的影响
DOI：
10.2472/jsms.57.563
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Y. Ochi
中科院分区：
文献类型：
--
作者：
K. Masaki;Y. Ochi
众所周知，如果在500°C或更低的温度下进行渗氮或渗碳，则在奥氏体不锈钢表面上的扩散层中形成氮和碳S相。为了研究氮和碳S相对316L型奥氏体不锈钢的高周疲劳性能的影响，对4种不同处理的试样进行了旋转弯曲疲劳试验：一种是470°C气体渗碳。另外三种分别在420°C、460°C和570°C下气体氮化。前三个试样的扩散层中有碳或氮S相，最后一个试样的扩散层中没有S相，这取决于温度。疲劳试验结果表明，S相对提高疲劳性能是有效的。氮S相对疲劳性能的改善作用大于碳S相。渗氮试样的疲劳强度随着扩散层厚度的增加而增加。外部观察表明，疲劳裂纹起源于表面上的缺口部分，由于疲劳载荷。虽然剥落行为取决于扩散物种，疲劳裂纹的扩展行为不依赖于他们。
It is known that nitrogen and carbon S phases are formed in the diffusion layer on the surface of austenitic stainless steels if nitriding or carburizing is performed at the temperature of 500°C or less. In order to investigate the effect of the nitrogen and carbon S phases on high cycle fatigue properties of type316L austenitic stainless steel, rotating bending fatigue tests were carried out for four specimens with different treatments : One was gas carburized at 470°C. The other three were gas nitrided at 420°C, 460°C and 570°C, respectively. The former three specimens had the carbon or the nitrogen S phase and the last one had no S phase in the diffusion layer, depending on the temperature. As the fatigue tests result, the S phase is effective to enhance the fatigue properties. The effect of fatigue properties improvement of the nitrogen S phase is greater than that of the carbon S phase. The fatigue strength increases with an increase in the thickness of the diffusion layer in the nitrided specimens. External observation suggests that the fatigue crack initiated from the chipped part on the surface due to fatigue loading. Although the chipping behavior depended on the diffusion species, the propagation behavior of fatigue cracks did not depend on them.