Properties of Cryogenic Treated Cemented Carbides (WC-Co)

2020 ◽  
Vol 403 ◽  
pp. 75-89
Author(s):  
Vojtěch Průcha ◽  
David Bricín ◽  
Antonín Kříž ◽  
Zdeněk Jansa
Keyword(s):  
Fracture Toughness ◽  
Cryogenic Treatment ◽  
The Other ◽  
Coarse Grained ◽  
Cemented Carbides ◽  
Polished Surface ◽  
X Ray Diffraction ◽  
Deep Cryogenic Treatment ◽  
Fine Grained ◽  
Disk Test

The present paper explores the effects of deep cryogenic treatment (DCT) on the properties of WC-Co cemented carbides. The investigation involved four different cemented carbide (CC) grades. Two of them were coarse-grained WC with grain sizes larger than 6 μm and binder fractions of 10 and 15 wt. %. The other two were fine-grained with WC grains of 0.5-0.8 μm and the same binder fractions of 10 and 15 wt. %. Their specimens were ground and polished to prepare them for DCT. In each specimen, one half of this polished surface was used for testing the properties of the CC before cryogenic treatment. The post-DCT properties were then determined on the other half. Properties of the cemented carbides prior to and after DCT were studied using optical and scanning electron microscopy, X-ray diffraction, hardness testing according to Vickers scale followed by calculation of fracture toughness KIC and a ball-on-disk test of the wear resistance of the surface. One of the findings was that cryogenic treatment led to a decrease in residual stresses and to lower fracture toughness KIC in the CC.

Conditional Belief and the Ramsey Test

2002 ◽  
Vol 51 ◽  
pp. 215-232
Author(s):  
Scott Sturgeon
Keyword(s):  
Everyday Life ◽  
Common Sense ◽  
The Other ◽  
Coarse Grained ◽  
Degrees Of Belief ◽  
Conditional Belief ◽  
Ramsey Test ◽  
Fine Grained

Consider the frameS believes that—.Fill it with a conditional, sayIf you eat an Apple, you'll drink a Coke.what makes the result true? More generally, what facts are marked by instances ofS believes (A→C)?In a sense the answer is obious: beliefs are so marked. Yet that bromide leads directly to competing schools of thought. And the reason is simple.Common-sense thinks of belief two ways. Sometimes it sees it as a three-part affair. When so viewed either you believe, disbelieve, or suspend judgment. This take on belief is coarse-grained. It says belief has three flavours: acceptance, rejection, neither. But it's not the only way common-sense thinks of belief. Sometimes it's more subtle: ‘How strong is your faith?’ can be apposite between believers. That signals an important fact. Ordinary practice also treats belief as a fine-grained affair. It speaks of levels of confidence. It admits degrees of belief. It contains a fine-grained take as well. There are two ways belief is seen in everyday life. One is coarse-grained. The other is fine-grained.

scholarly journals [Report on the presentation of two specimens of iron by Professor Stromeyer, Foreign Memb. R. S.]

1837 ◽  
Vol 3 ◽  
pp. 203-205
Keyword(s):  
Royal Society ◽  
Rare Metal ◽  
The Other ◽  
Coarse Grained ◽  
Molybdic Acid ◽  
Fine Grained ◽  
Considerable Portion

Professor Stromeyer, Foreign Memb. R.S., presented two speci­mens, one of the coarse-grained, the other of the fine-grained variety, of the remarkable mass of iron lately discovered near Magdeburg, and an account of which had been laid before the Royal Society of Got­tingen on the 14th of last month. This iron was found, in several de­tached lumps, about four feet below the mould, by Mr. Kote, who considered himself the more authorized to pronounce it meteoric, as, in the chronicles of Magdeburg, the descent of a fiery meteor is re­corded as having happened in the year 938. Professor Stromeyer has subjected this iron to a minute analysis, the results of which are very-interesting, inasmuch as, besides the alloy of nickel and cobalt, usually present in meteoric iron, he unexpectedly found a considerable portion of molybdenum, — a rare metal on our planet, occurring only in two combinations, viz. with sulphur, as glance molybdenum, and, as molybdic acid combined with oxide of lead, in the yellow lead ore of Carinthia and a few other places.

scholarly journals Crack-enhanced weathering in inscribed marble: a possible application in epigraphy

2021 ◽  
Vol 33 (2) ◽  
pp. 189-202
Author(s):  
Stylianos Aspiotis ◽  
Jochen Schlüter ◽  
Kaja Harter-Uibopuu ◽  
Boriana Mihailova
Keyword(s):  
Raman Spectroscopy ◽  
Penetration Depth ◽  
Environmental Conditions ◽  
Coarse Grained ◽  
Asia Minor ◽  
X Ray Diffraction ◽  
Western Turkey ◽  
Fine Grained ◽  
Rock Types ◽  
Micro Cracks

Abstract. Raman spectroscopy has been applied to check if there are detectible material differences beneath the inscribed and non-inscribed areas of marble-based written artefacts, which could be further used to visualize lost or hardly readable text via suitable mapping. As a case study, marble segments with ∼ 2000-year-old inscribed letters from Asia Minor (western Turkey) and marble gravestones with 66 ± 14-year-old inscriptions from the cemetery of Ohlsdorf (Hamburg, Germany) have been subjected to Raman spectroscopy, as well as to complementary X-ray diffraction, wavelength-dispersive electron probe microanalysis, and Fourier-transform infrared spectroscopy, to thoroughly study the effect of different environmental conditions, grain size, and inscription age on the nature and penetration depth of marble alteration. The results demonstrate that environmental conditions rule over the type of dominant weathering changes, which are carotenoid molecular inclusions produced by lichen and amorphous carbon for marbles from Hamburg and Asia Minor, respectively. The alteration is much stronger in medium- and coarse-grained than in fine-grained marble, but it is suppressed by letter colouring. In the absence of letter colouring, the weathering-related products in both ancient and modern engraved marbles are more abundant beneath than away from the engraved areas, and the penetration depth is larger due to the enhancement of fissures and micro-cracks around the inscribed areas. We show that the Raman intensity ratio between the strongest peak of the weathering-related product (ν(C=C) ∼ 1520 cm−1 for carotenoids or the G peak ∼ 1595 cm−1 for soot-like carbon) and the strongest peak of marble (CO3 stretching near 1087 cm−1) can serve as a quantitative marker to indirectly map the lateral distribution of cracks induced during the inscribing process and hence can potentially be used to trace lost text on vanished marble inscriptions. This approach can be applied to other rock types, but further studies are required to identify the corresponding autochthonous weathering-related products.

scholarly journals Wear evaluation and microstructure analysis of cryogenically treated AISI 440C Bearing steel

2021 ◽  
Author(s):  
Idayan A ◽  
C. Elanchezhian ◽  
B. Vijaya Ramnath ◽  
Palanikumar K
Keyword(s):  
Wear Resistance ◽  
Cryogenic Treatment ◽  
Research Work ◽  
Bearing Steel ◽  
X Ray Diffraction ◽  
Deep Cryogenic Treatment ◽  
X Ray ◽  
Heat Treated ◽  
Increase Wear Resistance ◽  
Wear Evaluation

In this research work, two types of cryogenic treatment such as deep cryogenic treatment (-196oC) and shallow cryogenic treatment (-80oC) have been adopted for wear resistance to increase in AISI 440C bearing steel. This paper has been focused to increase Wear Resistance (WR) through deep micro structural analyses, and also attention has been made to correlate the microstructure with the wear character of Deep Cryogenic treated (DCT) specimens, Conventional Heat Treated (CHT) specimens and Shallow Cryogenic Treated (SCT) specimens. Micro structural examinations have been carried out in the specimens through Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX) and X-Ray Diffraction (XRD). Wear characteristics of AISI 440C bearing steel has been studied. The outcome of the research disclosed that the DCT specimens have higher wear resistance than SCT and CHT specimens. The effective wear mechanisms recognized were the constitution of white layers and delamination of white layers. The microstructures of the materials have been varied through heat treatment process. The modification of Secondary Carbides (SCs) precipitation characteristics and its reduction of retained austenite in the microstructure have been correlated with wear character and these are the liable mechanism to raise the wear resistance of bearing steels through DCT.

DIROS 500

Alloy Digest ◽  
2011 ◽  
Vol 60 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Physical Properties ◽  
Pressure Vessel ◽  
High Strength ◽  
Heat Treating ◽  
The Other ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Fine Grained ◽  
Sour Service

Abstract Diros 500 is a fine-grained pressure vessel steel delivered in two grades: one as high strength, the other for sour service. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-630. Producer or source: Dillinger Hütte GTS.

The Influence of Post-Quenching Deep Cryogenic Treatment on Tempering Processes and Properties of D2 Tool Steel. Studies of Structure, XRD, Dilatometry, Hardness and Fracture Toughness

2006 ◽  
Vol 258-260 ◽  
pp. 415-420 ◽  
Author(s):  
Ignacy Wierszyłłowski
Keyword(s):  
Fracture Toughness ◽  
Cryogenic Treatment ◽  
Cryogenic Temperatures ◽  
Deep Cryogenic Treatment ◽  
Treated Steel ◽  
The Matrix ◽  
Xrd Studies ◽  
Number Of Publications ◽  
D2 Steel ◽  
Tetragonal Martensite

A significant increase in durability of cryogenically treated tools after quenching was reported by a number of publications [1, 2]. As research studies show [4, 5, 6, 7], the main reason for this is the kind of carbides precipitated during tempering at temperature range of 150 –200 0C, which is different than in the case of conventional treatment. These carbides are finer and more evenly distributed in the matrix of steel. The number of carbides is higher than in conventionally treated steels because of higher fraction of martensite in cryogenically treated steels produced by retained austenite transformation at cooling to deep cryogenic temperatures. The number of carbides precipitated from martensite at low temperatures of tempering is proportional to shrinkage produced at the same temperatures of tempering. Calculations on the basis of dilatometric experiments show that the shrinkage difference between the same D2 steel cryogenically and conventionally treated is higher than that which results from the increased fraction of martensite in cryogenically treated steel. The XRD studies of cryogenically treated steel show a presence of two kinds of martensites differing in tetragonality. Low temperature tempering of cryogenically treated steel produced two types of carbides – ε carbide and η carbide. The conventionally treated steel consists of one kind of tetragonal martensite and one kind of carbide - the ε carbide. The hardness of cryogenically treated samples was somewhat higher than in conventionally treated ones, while fracture toughness of conventionally treated samples was somewhat higher than in cryogenically treated ones. The results obtained were discussed in reference to literature data.

The Mid-Atlantic ridge near 45° N. VII. Magnetic properties and opaque mineralogy of dredged samples

1970 ◽  
Vol 7 (2) ◽  
pp. 239-256 ◽  
Author(s):  
C. M. Carmichael
Keyword(s):  
Magnetic Properties ◽  
Remanent Magnetization ◽  
Complex Structure ◽  
Magnetic Anomalies ◽  
Natural Remanent Magnetization ◽  
Coarse Grained ◽  
X Ray Diffraction ◽  
Field Polarity ◽  
Fine Grained ◽  
Mid Atlantic Ridge

Measurements of the magnetic properties, paleomagnetic field intensity, and the inferred paleomagnetic field polarity have been made using fine grained basalt and coarser grained rock samples dredged from the mid-Atlantic ridge near 45° N and supplied by the Geological Survey of Canada. The opaque mineralogy of the samples was studied by microscope, Curie point, and X-ray diffraction techniques. The natural remanent magnetization of the basalt is of the order of 5 to 10 × 10−3 e.m.u./cm3 with some values from the center of the median valley reaching 10−1 e.m.u./cm3. Magnetic anomalies over the ridge can be accounted for by the remanent magnetization of a few hundred meters of this basalt. The coarse grained rocks were relatively weakly magnetized, and while they contribute little to the magnetic anomalies, their diverse character suggests that the major portion of the oceanic crust, below a thin veneer of fine grained basalt, has differentiated into a complex structure.

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