Quick estimating method of giga-cycle fatigue properties by an intermittent ultrasonic loading

间歇超声加载千兆周疲劳性能快速估算方法

• 批准号: 13650082
• 负责人: ISHII Hitoshi
• 金额: $ 2.3万
• 依托单位: Shizuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650082/
• 关键词: Ultrasonic fatigue; Intermittent ultrasonic loading; Giga-cycle fatigue; High Strength steel; Subsurface crack nucleation; Inclusion; Case hardening steel; Notched specimen; 高強度網; 浸炭処理網; P-S-N線図

S-N curves of the materials with various strength steels were determined up to the giga-cycle regime by an intermittent ultrasonic fatigue method, and the results were compared to those obtained by a conventional method. The usefulness of this method as a quick determination of the fatigue strengths was confirmed. The reason of applying ultrasonic wave train intermittently (pulsed mode) was to avoid temperature raise of the specimen by heat generation due to very high cyclic deformation. No effect of the duty-pause period on the fatigue properties in the very high cycle regime above 10^7 cycles was observed as long as no heat raise occurs in the specimen, and the following results were obtained by using 30 ms duty period and 70 ms pause period. P-S-N diagrams up to the giga-cycle regime were obtained on the S35C and SNCM439 tempered at high temperature by using 150 test pieces. Thus obtained P-S-N diagrams show quite good correlation with the results in the data book by JSMS or NRIM. Furthermore, the S-N curves of the maraging steels, which exhibit no endurance limit, were obtained up to the giga-cycle regime. In the specimens fractured below 10^7 cycles, crack initiation was always from the surface, while it was at subsurface initiation from the inclusions in the specimens survived more than 10^7 cycles. Improvement of the high cycle fatigue properties was achieved by reforming the inclusion size through manufacturing process. Such results that usually take a few years to obtain by a conventional method can be obtained within a few months and it is shown that this method is a powerful tool for developing new materials. Success applications were also made to the bearing steel of SUJ2 and the case hardening steels of SCr220 and SNCM 420 and to the notched specimen.

通过间歇超声疲劳法测定了各种强度钢材料的 S-N 曲线直至千兆循环状态，并将结果与​​传统方法获得的结果进行了比较。证实了该方法作为快速测定疲劳强度的有用性。间歇地施加超声波序列（脉冲模式）的原因是为了避免由于非常高的循环变形而产生的热量导致样品温度升高。只要样品中不发生发热，就观察到工作暂停期对超过 10^7 次循环的极高循环状态下的疲劳性能没有影响，并且通过使用 30 ms 工作期和 70 ms 暂停期获得以下结果。使用 150 个试件在高温回火的 S35C 和 SNCM439 上获得了高达千兆循环范围的 P-S-N 图。由此得到的P-S-N图与JSMS或NRIM数据手册中的结果显示出很好的相关性。此外，还获得了马氏体时效钢的 S-N 曲线，其没有表现出耐久性极限，直至千兆循环状态。在低于 10^7 个周期断裂的样本中，裂纹萌生总是从表面开始，而裂纹萌生则在次表面处，源自存活超过 10^7 个周期的样本中的夹杂物。通过制造工艺改变夹杂物尺寸，实现了高周疲劳性能的改善。传统方法通常需要几年才能获得的结果可以在几个月内获得，这表明该方法是开发新材料的有力工具。在SUJ2轴承钢、SCr220和SNCM 420表面硬化钢以及缺口试样上也取得了成功的应用。

项目成果

Hitoshi Ishii, Yorinori Kumagai and Atsushi Takahashi: "Giga-cycle Fatigue Properties of Carburized and Water Jet Peened Case Hardening Steels"9th International Conference on the Mechanical Behavior of Materials. (2003)

Hitoshi Ishii、Yorinori Kumagai 和 Atsushi Takahashi：“渗碳和水喷丸表面硬化钢的千兆循环疲劳性能”第九届材料机械行为国际会议。

Hitoshi Ishii, Yohei Tagchi, Kazuo Ishii, Hirofumi Akagi: "Ultrasonic bending fatigue testing method for thin sheet materials"International Conference on Advanced Technology in Experimental Mechanics '03. (発行予定). (2003)

Hitoshi Ishii、Yohei Tagchi、Kazuo Ishii、Hirofumi Akagi：“薄板材料的超声波弯曲疲劳测试方法”实验力学先进技术国际会议03（待出版）。

Hitoshi Ishii, Kazufumi Yamanaka and Keiichiro Tohgo: "Giga-cycle Fatigue Strengths in Some High Strength Steel by Ultrasonic Fatigue Testing"Materials Science Research International. STP-1. 59-63 (2001)

Hitoshi Ishii、Kazufumi Yamanaka 和 Keiichiro Tohgo：“通过超声波疲劳测试测定某些高强度钢的千兆循环疲劳强度”国际材料科学研究。

Hitoshi Ishii, Kazufumi Yamanaka, Keiichiro Tohgo: "Giga-cycle Fatigue Strengths in Some High Strength Steel by Ultrasonic Fatigue Testing"Materials Science Research International. STP-1. 59-63 (2001)

Hitoshi Ishii、Kazufumi Yamanaka、Keiichiro Tohgo：“通过超声波疲劳测试测定某些高强度钢的千兆循环疲劳强度”国际材料科学研究。

Hitoshi Ishii, Tooru Yagasaki and Hirofumi Akagi: "Evaluation of giga-cycle fatigue properties of some maraging steels by intermittent ultrasonic loading"Fatigue and Fracture of Engineering Materials and Structures. 25, 8-9. 831-835 (2002)

Hitoshi Ishii、Tooru Yagasaki 和 Hirofumi Akagi：“通过间歇超声加载评估某些马氏体时效钢的千兆循环疲劳性能”工程材料和结构的疲劳和断裂。