IMPROVEMENT OF PROOF FATIGUE WITH GRADIENT OF MECHANICAL PROPERTIES OF SURFACE LAYER

表层力学性能梯度提高疲劳强度

• 批准号: 10650093
• 负责人: KANESHIRO Hideo
• 金额: $ 0.9万
• 依托单位: UNIVERSITY OF THE RYUKYUS
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650093/
• 关键词: Salt bath nitriding; Plasma nitriding; Hollow cathode method; Fatigue strength; Dislocation structures; Crack initiation; Fatigue fracture mechanism; 塩沿窒化; ホローカソード放電; 腐食疲労; 接触疲労; すべり率; 低温窒化; 内部組織; 疲労特性; 接触疲労き裂; 窒化ローラ; 表面改質

Salt bath nitriding or plasma nitriding were applied to structural steel SS400 and low carbon steel S15CK respectively, and those fatigue properties and fatigue fracture mechanisms were investigated. The results obtained are as follows :(1) In the case of nitrided SS400, fatigue cracks are generated at the separated regions between the compound layer and the diffusion layer and propagate in the inner region of the diffusion region.(2) It is found that Fatigue strength of the nitrided steel is affected by the internal structures within the materials before nitriding treatment.(3) Dislocation structures before nitriding are reorganized by the nitriding treatment. Such structures are changed into cell structutes by the cyclic stress.(4) In the case of the plasmanitrided S15CK, fatigue cracks are generated along the needlelike nitrides and propagate in the connection of the nitrides.(6) It is found that the increase of the nitrogen content in the reaction gases and gas pressure are effective in the appropriate nitriding of the narrow gap. It is also found that the hollow cathode discharge are effective in the enhancement of the nitriding

分别对结构钢SS 400和低碳钢S15 CK进行盐浴渗氮或等离子渗氮，研究其疲劳性能和疲劳断裂机制。结果表明：（1）400不锈钢渗氮后，疲劳裂纹产生于化合物层与扩散层之间的分离区，并在扩散区内部扩展。(2)结果表明，氮化钢的疲劳强度受氮化前材料内部结构的影响。(3)氮化处理使氮化前的位错结构发生重组。这种结构在循环应力作用下转变为胞状结构。(4)在等离子氮化S15 CK的情况下，疲劳裂纹沿着针状氮化物产生，并在氮化物的连接处扩展。(6)结果表明，提高反应气体中氮含量和气体压力对窄间隙的适当渗氮是有效的。空心阴极放电对渗氮层的强化效果也很好

项目成果

兼城英夫: "窒化した圧延鋼の疲労特性と転位組織"日本機械学会論文集(A編). 67巻. 94-101 (2001)

金城秀夫：“氮化轧制钢的疲劳特性和位错结构”日本机械工程学会会刊（A版）67. 94-101（2001年）。

H.Kaneshiro et al.: "Fatigue Properties and Dislocation Structures of Nitrided SS400"Trans.JSME. vol.65. 808-815 (1999)

H.Kaneshiro 等人：“氮化 SS400 的疲劳特性和位错结构”Trans.JSME。

眞喜志隆: "ホローカソード放電を利用したイオン窒化の迅速化"第50回熱処理技術協会講演概要集. 25-26 (2000)

Shitaka Maki：《利用空心阴极放电加速离子氮化》第50届热处理技术协会讲座摘要25-26（2000）。

兼城英夫: "窒化したSS400の疲労特性と転位組織"日本機械学会論文集(A編). 65巻632号. 808-815 (1999)

Hideo Kaneshiro：“渗氮 SS400 的疲劳特性和位错结构”日本机械工程学会会刊（A 版），第 65 卷，第 632 期。808-815（1999 年）。

眞喜志隆: "すき間部のイオン窒化に及ぼす処理条件の影響"第46回熱処理技術協会講演概要集. 3-4 (1998)

Shitaka Maki：“加工条件对缝隙离子渗氮的影响”第46届热处理技术协会讲座摘要3-4（1998年）。