Study on Statistical Giga-cycle Fatigue Property of High Strength Steels and Establishment of Reliability Assurance Engineering

高强钢统计千兆周疲劳性能研究及可靠性保证工程建立

• 批准号: 11650106
• 负责人: SAKAI Tatsuo
• 金额: $ 2.3万
• 依托单位: Ritsumeikan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650106/
• 关键词: High strength steels; Reliability analysis; Statistical fatigue property; Ultra-long life fatigue; Mixed Weibull distribution; Duplex S-N property; Fatigue strength; Fish-eye; FGA; 長寿命疲労特性; フィッシュアイ

Main results in this research are summarized as follows;(1) Two-step S-N curve often reported on several high strength steels and case-hardened steels can be well interpreted as the duplex S-N curves consisting of two different S-N curves for the respective fracture modes of surface induced fracture and interior inclusion induced fracture.(2) Above duplex S-N characteristics in the long life regime are common for the rotating bending and the axial loading but the separation of the respective S-N curves in the rotating bending is distinct more than that in the axial loading.(3) Slope of the S-N curve in the interior inclusion induced fracture is less than that in the surface induced fracture. This aspect can be attributed to the difference of the fatigue crack growth laws in the room air and in the vacuum.(4) Stress intensity factor range at the front of the fine granular area (FGA) around the interior inclusion at the crack origin is corresponding to the threshold value of the fatigue crack propagation of the material ΔK_<th>.(5) Fatigue life distribution at a stress level is well explained as the mixed mode of Weibull distribution consisting of the respective life components of the surface induced fracture and the interior inclusion induced fracture. Statistical fatigue properties can be quantitatively analyzed through the stress dependence of Weibull parameters for the respective fatigue life distribution.(6) Total fatigue life of the bearing steel can be separated into three components for the crack initiation life, the formation life of FGA and the formation life of the fish-eye.

本研究的主要成果总结如下：(1)几种高强度钢和表面硬化钢的两步S-N曲线可以很好地解释为由表面诱发断裂和内部夹杂物诱发断裂两种不同断裂模式的两条不同的S-N曲线组成的双重S-N曲线.(2)在长寿命区，上述二重的S-N特征在旋转弯曲和轴向加载下是常见的，但在旋转弯曲中各自的S-N曲线的分离比在轴向加载时明显更明显.(3)内部夹杂物诱导断裂中的S-N曲线的斜率小于表面诱导断裂中的S-N曲线.这可归因于室内空气和真空中疲劳裂纹扩展规律的不同。(4)裂纹起始处内部夹杂物周围细小颗粒区前沿的应力强度因子范围对应于材料ΔK_(Th)的疲劳裂纹扩展门槛值。(5)应力水平下的疲劳寿命分布可以很好地解释为由表面诱发断裂和内部夹杂物诱发断裂各自的寿命分量组成的威布尔分布的混合模式。通过疲劳寿命分布的威布尔参数的应力相关性，可以定量地分析轴承钢的统计疲劳性能。(6)轴承钢的总疲劳寿命可以分解为裂纹萌生寿命、FGA形成寿命和鱼眼形成寿命三个部分。

项目成果

中島正貴, 酒井達雄, 清水利弘: "高強度鋼SUJ2におけるFish-eye破壊過程の観察"日本機械学会論文集(A編). 65. 2504-2510 (1999)

Masataka Nakajima、Tatsuo Sakai、Toshihiro Shimizu：“高强度钢 SUJ2 鱼眼断裂过程的观察”日本机械工程师学会会议记录（ed. A）65. 2504-2510（1999）。

M. Nakajima, T. Sakai and T. Simizu: "An observation of fish-eye fracture process in high strength steel SUJ2"Transactions of the Japan Society of Mechanical Engineers. Vol. 65-A, No. 640. 2504-2510 (1999)

M. Nakajima、T. Sakai 和 T. Simizu：“高强度钢 SUJ2 鱼眼断裂过程的观察”日本机械工程师学会会刊。

T. Sakai, M. Takeda and N. Oguma: "Effect of strength level on fatigue property of several structural steels in ultra-wide life region"Proc. Fatigue 2002. Vol. 5. 2987-2994 (2002)

T. Sakai、M. Takeda 和 N. Oguma：“超宽寿命区域中强度水平对几种结构钢疲劳性能的影响”Proc。

Tatsuo SAKAI: "Experimental Evidence of Duplex S-N Characteristics in Wide Life Region for High Strength Steels"Proc. 7^<th> International Fatigue Congress. Vol.1. 573-578 (1999)

Tatsuo SAKAI：“高强度钢宽寿命区双相 S-N 特性的实验证据”Proc。

Tatsuo SAKAI: "A Study on Fatigue Property of High Strength Steels for Mechanical Tool Use"Fracture and Damage Mechanics. 15-23 (1999)

Tatsuo SAKAI：“机械工具用高强度钢的疲劳性能研究”断裂与损伤力学。