Inclusion Rating by Statistics of Extreme for Electron Beam Remelted Super Clean Bearing Steel and Its Application to Fatigue Strength Prediction

Toriyama, Toshiyuki; Murakami, Yukitaka; Yamashita, Teruo; Tsubota, Kazuichi; Furumura, Kyozaburo

doi:10.2355/tetsutohagane1955.81.10_1019

Cited by 23 publications

(11 citation statements)

References 1 publication

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“…One trick to guess at the dimension and number of large-size inclusions that cannot be observed -except by chance -is to execute a statistical sleigh of hand, whereby the distribution of inclusions, measured at small or intermediate dimensions, is extrapolated to the larger sizes (Statistics of extreme values (SEV) method) [27,28]. Practically, there are several inclusion populations in solid steel, due for example to deoxidation, reoxidation, various other contamination mechanisms and process mishaps, and therefore the case for all of them to align along a single distribution curve is fairly weak!…”

Section: Cleanliness Estimation and Measurementmentioning

confidence: 99%

Steel cleanliness and environmental metallurgy

Birat¹

2016

Metall. Res. Technol.

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-Clean steels were "invented" in the middle of the 20th century, at a time when steels started to be produced en masse and when it was understood that quality should also be addressed as a special and important issue, both in terms of the strategy of the sector and as a major research topic for the science and technology that accompanies the industry. The series of Clean Steel conferences, launched in Hungary in 1970 and organized every 4 years since then, with Paul Tardy in the organizing committee or in the lead, have been providing important time markers of this evolution. Since then, major progress was made by the introduction in most steel shops of secondary or ladle metallurgy, which was invented in the process, while steel cleanliness was defined precisely in standards and textbooks. The discoveries of pioneers have become state-of-the art and, today, a steady state situation has been reached, where research continues in using new tools and methods to refine the topic, while new comers, mainly from the BRIC countries, are contributing their understanding of the topic to the international steel community. The distinction between special steels and carbon steels got blurred in this historical process, as similar secondary metallurgy tools were used for making both kinds of steels and, in essence, steel ceased to be a simple commodity and most steels became special to some extend. Clean steels have thus not become much more sophisticated recently, but rather much more common and mainstream. The expression "clean steel" stems from a vision of the purity of the metal in terms of minor elements, which had been controlled until then only at the margin compared to the major elements, iron, carbon, silicon and manganese. This is today a somewhat passéed vision as metallurgy has become a much more holistic and systemic technology, whereby steels are defined in terms of global composition, of distribution of phases, including the minor phases that are known as non-metallic inclusions, of microstructures and, more often than not, in terms of applications and properties in service. Moreover, steels have time extensions, which are discussed as life cycle or value chain and are thus embedded in the anthroposphere and its intersection with the biosphere and the geosphere. This emphasizes the fact that steels are made from raw materials, primary and secondary -thus including scrap from recycling -, that they are transformed into artifacts that participate to the life of society and eventually are disposed of at end of life to feed back into the circular economy. This holistic vision is what we call "environmental metallurgy". It is linked to clean steel production and constitutes another dimension of the cleanliness of steel. Plenary presentation to the 9th International Conference on Clean Steel; 8-10 September 2015; Budapest; Hungary S teel is a metal, which combines a robust set of properties for making a wide variety of things with a fairly "cheap" price. It has thus become ubiquitous.Iron and steel emerged i...

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Section: Cleanliness Estimation and Measurementmentioning

confidence: 99%

Steel cleanliness and environmental metallurgy

Birat¹

2016

Metall. Res. Technol.

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“…One is the statistics of extreme values (SEV) method, which was developed and standardized by Murakami and co-workers. [1][2][3][4] Moreover, Takahashi has studied the relationship between EVD of particle size from the 2D and 3D measurements by using numerical simulations based on the SEV method.…”

Section: Introductionmentioning

confidence: 99%

Estimation of the Maximum Carbide Size in a Hypereutectic High Chromium Cast Iron Alloyed with Titanium

2013

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In this study, in order to obtain complete size distribution results, the maximum carbide size in a Fe-17 mass% Cr-4 mass% C hypereutectic High Chromium Cast Iron (HCCI) produced with different cooling conditions, titanium additions and heat treatment conditions was determined by using the statistics of extreme values (SEV) method. In addition, the shape factor, circularity, was estimated in order to classify the type of carbides (primary M7C3 carbides, TiC carbides and secondary M7C3 carbides). Compared to the smaller size carbides, such as TiC carbides and secondary M7C3 carbides, it was found that the slope of the extreme value distribution (EVD) regression lines is lower for the large sized carbides such as primary M7C3 carbides than for the smaller carbides. Moreover, it was found that the circularity value for the larger size carbides is higher than for the smaller carbides. Furthermore, the estimated and observed maximum carbide sizes were compared with each other for all carbide types. The characteristic of the different carbide types are summarized and classified based on the shape factor. Finally, the relationship between the carbide size distribution including the maximum carbides size and mechanical properties is discussed based on the combination of a size distribution analysis and a maximum size analysis.

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“…Although it showed a fatigue limit of 820 MPa at 5 × 10 9 cycles, which is at a similar level to that of AF400, its fatigue strength at around 10 6 cycles was higher. Figure 9 shows typical FE-SEM images of internal (1), (2) since inclusions were not found on these fracture surfaces, and an EDAX analysis of the initiation sites showed Fe alone. However, a previous report (7) has revealed that, when a hard TiN inclusion is an initiation site, separation from the matrix is not accompanied, unlike the case for Al 2 O 3 , and therefore, only a part of TiN or minor quantities appear on the fracture surface in many cases.…”

Section: ×10mentioning

confidence: 99%

“…However, in high-strength steels with a strength level over 1 200 MPa, internal fractures occur with initiation sites at inclusions and matrix cracks (1), (2) , causing the problem called gigacycle fatigue when the number of cycles exceeds 10 7 . It is known that the fatigue limits of steels are usually approximately onehalf those of tensile strengths (3) .…”

Section: Introductionmentioning

confidence: 99%

Gigacycle Fatigue Properties of V-Added Steel with an Application of Modified Ausforming

Hirukawa

Furuya

Matsuoka

2006

JSME Int. J., Ser. A

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This report reveals gigacycle fatigue properties for a modified-ausformed V-added steel with the chemical composition of 0.3 C-0.3 Si-1.0 Cr-0.7 Mo-0.3 V in mass %. Modifiedausformed and oil-quenched steels were prepared for fatigue tests, followed by tempering at 400• C and 600• C. The tensile strengths of the 600 • C tempered steels were almost equal to those of the 400• C tempered versions because of secondary hardening due to fine precipitation of vanadium carbides. The fatigue properties of the 600• C tempered version of oilquenched steel (QT600) showed little difference from the 400 • C tempered version (QT400) in spite of the fine precipitation of vanadium carbides. The modified-ausformed steels (AF400 and AF600) revealed higher fatigue limits at 5 × 10 9 cycles than the oil-quenched versions (QT400 and QT600), although the difference between AF400 and AF600 was small. The remarkable difference between AF400 and AF600 was fatigue strengths at around 10 6 cycles, i.e. the fatigue strength of AF600 at those cycles was higher than that of AF400. Based on the above results, the effect of the fine precipitation of vanadium carbides was small on the gigacycle fatigue properties, while modified-ausforming could improve those properties. On the other hand, the multiple effects of the fine precipitation and modified-ausforming was large on the fatigue strength at around 10 6 cycles.

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Inclusion Rating by Statistics of Extreme for Electron Beam Remelted Super Clean Bearing Steel and Its Application to Fatigue Strength Prediction

Cited by 23 publications

References 1 publication

Steel cleanliness and environmental metallurgy

Steel cleanliness and environmental metallurgy

Estimation of the Maximum Carbide Size in a Hypereutectic High Chromium Cast Iron Alloyed with Titanium

Gigacycle Fatigue Properties of V-Added Steel with an Application of Modified Ausforming

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