Database of statistics of extreme values of inclusion size areamax

Metal Fatigue ◽  
2019 ◽  
pp. 711-716
Keyword(s):  
Extreme Values ◽  
Inclusion Size

Study on the Influence of Inclusion and Void on Fatigue Life of Bearing Steel Using Statistics of Extreme Values

2011 ◽  
Vol 284-286 ◽  
pp. 1258-1261 ◽  
Author(s):  
Chin Chuan Hsu ◽  
Ho Hua Chung
Keyword(s):  
Fatigue Life ◽  
Nonmetallic Inclusion ◽  
Extreme Values ◽  
Energy Dispersive Spectrometer ◽  
Inclusion Size ◽  
Bearing Steel ◽  
Propagation Path ◽  
Void Size ◽  
Inclusion Type ◽  
Bearing Steels

The maximum nonmetallic inclusion size and void of bearing steel has been analyzed using statistics of extreme values (SEV) in this study, and the influence of the maximum nonmetallic inclusion and void size on fatigue life of bearing steel has been discussed as well. Scanning electron microscopy (SEM) was used to measure the inclusion and void size, and the identification of inclusion type has been carried out by energy dispersive spectrometer (EDS). The results show that there are small hard round oxides or sharp TiN inside or beside the soft MnS strip in steels, single MnS strips and small clustered Al2O3 are also present. Most of voids in steels are branched rod-like or feathery, and the size of void is much smaller than inclusion for all steels. Therefore, the void is not the fatigue orgin for bearing steels. By adopting the criterion of return period (T) at 200, a serial analysis shows that the relation between inclusion/void size and fatigue life for steels is inverse proportion except B steel. This results from that larger inclusion could not only initialize crack, but also increase the propagation path of crack and accelerate fracture.

Analysis of Influence of Aluminum Content on Inclusion Characteristic and Fatigue Life of Bearing Steel Using Statistics of Extreme Values

2014 ◽  
Vol 939 ◽  
pp. 11-18 ◽  
Author(s):  
Chin Chuan Hsu ◽  
Ho Hua Chung
Keyword(s):  
Fatigue Life ◽  
Nonmetallic Inclusion ◽  
Aluminum Content ◽  
Extreme Values ◽  
Energy Dispersive Spectrometer ◽  
Inclusion Size ◽  
Bearing Steel ◽  
Dominant Factor ◽  
Bearing Steels ◽  
Alumina Cluster

In this study, we predicted the maximum nonmetallic inclusion size of bearing steel using statistics of extreme values (SEV) approach, and discussed that the influence of aluminum content on the nonmetallic inclusion characteristic and fatigue life of bearing steel. The inclusion size and type was measured and identified by a scanning electron microscopy (SEM) and an energy dispersive spectrometer (EDS) respectively. The result shows that most inclusions in steels are oxysulfide and alumina cluster. A tendency was also found that the alumina size increases with increasing aluminum content, but the oxysulfide size almost remains unchanged. Furthermore, alumina clusters were formed in steel if more deoxidizer aluminum was added to the molten steel during metallurgical process. In addition, the fatigue life of steel is inversely proportional to alumina size, but it seems independent of oxysulfide size. Therefore, this study suggests that the dominant factor of influence on the fatigue life of bearing steel is alumina instead of oxysulfide. The results reported here would be beneficial to steel manufacturers attempting to improve the fatigue resistance of bearing steels.

The Influence of Argon Flow on Inclusion Characteristic and Fatigue Life of Continuous Casting Bearing Steels

2011 ◽  
Vol 418-420 ◽  
pp. 972-976
Author(s):  
Chin Chuan Hsu ◽  
Ho Hua Chung
Keyword(s):  
Fatigue Life ◽  
Continuous Casting ◽  
Extreme Values ◽  
Energy Dispersive Spectrometer ◽  
Casting Process ◽  
Inclusion Size ◽  
Bearing Steel ◽  
Inclusion Type ◽  
Bearing Steels ◽  
Argon Flow

In this study, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) are used to measure the inclusion size and identify the inclusion type respectively. The evaluated maximum nonmetallic inclusion size of bearing steel has been obtained by using statistics of extreme values (SEV). The influence of argon flow of the continuous casting process on the inclusion characteristics of bearing steels has been estimated, the influence of size and type of inclusion of bearing steel on its fatigue life have been discussed as well. It was found that most inclusions in steels are oxysulfide and alumina cluster. With the decreasing of the argon flow, the inclusion size gets larger and the amount of cluster-type inclusion also increases. In addition, by adopting the criterion of return period (T) at 200, the serial analyses show that the relation between predicted inclusion size for max and the argon flow is inverse proportion, but the fatigue life of steel is proportional to argon flow. A correlation among argon flow, inclusion size and fatigue life of bearing steel has been established in this study.

Evaluation of Maximum Inclusion Size and Fatigue Limit for High Strength Steel in Rotating Rending

2012 ◽  
Vol 482-484 ◽  
pp. 1622-1627
Author(s):  
Ping Wang ◽  
Wei Li ◽  
Dong Ming Wang
Keyword(s):  
Fatigue Limit ◽  
High Strength Steel ◽  
Extreme Values ◽  
Control Volume ◽  
High Strength ◽  
Inclusion Size ◽  
Fracture Surfaces ◽  
Fatigue Design ◽  
Rotating Bending ◽  
Very High

Based on the observation of fracture surfaces for a low-alloy high strength steel under rotating bending in very high cycle regime, a newly defined method about inspection plane under rotating bending was developed in this paper. By using the statistics of extreme values (SEV) method, the maximum sizes of inclusion and FGA corresponding to the control volume of specimen are evaluated to be about 41.38 μm and 58.51 μm on the basis of this newly defined inspection plane, and the corresponding values of fatigue limit are evaluated to be 690 MPa and 654 MPa, respectively. It should be noted that fatigue design based on former involves a certain amount of risk in very high cycle regime.

Study on the Influence of Reduction in Area on Fatigue Life of Bearing Steel Using Statistics of Extreme Values

2011 ◽  
Vol 189-193 ◽  
pp. 3592-3595 ◽  
Author(s):  
Ho Hua Chung ◽  
Chin Chuan Hsu
Keyword(s):  
Fatigue Life ◽  
Nonmetallic Inclusion ◽  
Extreme Values ◽  
Energy Dispersive Spectrometer ◽  
Inclusion Size ◽  
Rolling Process ◽  
Bearing Steel ◽  
Inclusion Type ◽  
Hard Inclusion ◽  
Reduction In Area

The maximum nonmetallic inclusion size and type of bearing steel has been analyzed using statistics of extreme values (SEV) in this study, and the influence of reduction in area on the maximum nonmetallic inclusion size and the fatigue life of bearing steel have been discussed as well. Scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) are used to measure the inclusion size and identify the inclusion type respectively. By adopting the criterion of return period (T) at 200, a serial analysis shows that with increasing the reduction in area of steel, the predicted inclusion size for √area max is decreasing, and the fatigue life is prolonging. This results from the defragment of hard inclusion during rolling process, and the decrease of concentration of stress around the inclusion.

Study on the Influence of Oxygen Content on Fatigue Life of Bearing Steel Using Statistics of Extreme Values

2011 ◽  
Vol 287-290 ◽  
pp. 879-882 ◽  
Author(s):  
Ho Hua Chung ◽  
Chin Chuan Hsu
Keyword(s):  
Fatigue Life ◽  
Nonmetallic Inclusion ◽  
Oxygen Content ◽  
Extreme Values ◽  
Energy Dispersive Spectrometer ◽  
Inclusion Size ◽  
Rolling Process ◽  
Bearing Steel ◽  
Inclusion Type ◽  
Hard Inclusion

In this study, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) are used to measure the inclusion size and identify the inclusion type respectively. The evaluated maximum nonmetallic inclusion size of bearing steel has been obtained using statistics of extreme values (SEV), and the influence of oxygen content on the maximum nonmetallic inclusion size and the fatigue life of bearing steel have also been discussed. By adopting the criterion of return period (T) at 200, the serial analyses show that the predicted inclusion size formax is proportional to the oxygen content of steel, but the relation between fatigue life and oxygen content of steel is inverse proportion. This results from the defragment of hard inclusion during rolling process, and the decrease of concentration of stress around the inclusion.

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