Improving the quality of steel casting

1974 ◽  
Vol 10 (4) ◽  
pp. 362-363
Author(s):  
A. A. Markov
Keyword(s):  
Steel Casting

Using the sonic method for controlling the quality of steel-casting plugs

Refractories ◽  
1963 ◽  
Vol 4 (9-10) ◽  
pp. 503-506
Author(s):  
P. A. Lande ◽  
A. I. Varvarina ◽  
Z. N. Ivanova
Keyword(s):  
Steel Casting ◽  
Sonic Method

scholarly journals Effect of steel casting speed mode on quality of continuously casted billet

2019 ◽  
Vol 75 (4) ◽  
pp. 460-464
Author(s):  
A. M. Stolyarov ◽  
A. M. Retunskaya ◽  
M. G. Potapov ◽  
M. V. Potapova
Keyword(s):  
Casting Speed ◽  
Steel Casting ◽  
Surface Defects ◽  
Continuous Caster ◽  
General Tendency ◽  
Withdrawal Speed ◽  
Metallic Inclusions ◽  
General Quality ◽  
Speed Mode

The speed of billet withdrawal from a continuous caster (CC) mold has a decisive effect on the CC productivity. However, increase of the speed results in an increase of pollution of the CC metal by non-metallic inclusion and increase of surface defects of CC billet. Estimation of steel casting speed mode impact on the degree of different defects formation presented for long products CC billets, casted at a five-strand CC of radial type. Defects of CC billet from Ст3сп steel grade studied for a billet having section of 150×150 mm. The purpose of the study was to determine the degree of influence of withdrawal speed, metal chemical composition and billets cross section dimensions on billets quality. Array of industrial data of more than 550 billets studied, 80.4% of which were casted by an open stream and the balance – by a closed stream. As a result of the CC billets quality study it was confirmed, that during metal casting by an open stream the degree of evolution of form defect, like rhombic defects, internal and surface defects is higher comparing with those when casting by a closed stream. General tendency of increase of the CC metal pollution by non-metallic inclusions at the increase of billet withdrawal speed. The tendency is similar for both casting by an open and by a closed stream. However, during casting by an open stream the increase takes place rather evenly. During casting by a closed stream a sharp increase of billets with defects were observed at the billets withdrawal speed exceeding 2.4 m/min. Linear dependencies of billets withdrawal speed while casting by a closed stream on the degree of liquation cracks evolution and general strips, edge point pollutions and peripheral fine structure metal zone thickness determined. To improve the long products billets surface, casted by a closed stream, it was recommended to restrict the withdrawal speed of the billet from a carbon steel of general quality by the value of 2.4 m/min.

Effect of Continuous Casting Parameters on Quality of Billets Manufactured by UMMC Steel LLC

2017 ◽  
Vol 265 ◽  
pp. 952-961
Author(s):  
A.N. Kalitaev ◽  
V.D. Tutarova ◽  
A.N. Shapovalov
Keyword(s):  
Steel Casting ◽  
Phosphorus Content ◽  
Medium Carbon Steel ◽  
Steel Grade ◽  
Low Carbon ◽  
Medium Carbon ◽  
Axial Porosity ◽  
Billet Quality ◽  
Open Cast

The analysis of the production records on casting 150õ150mm billets at UMMC Steel LLC has made it possible to define the basic factors worsening the billet quality and increasing the rejection of the rolled materials: steel casting in case the sulfur and phosphorus content exceeds 0.015 % and overheat is more than 30°Ñ. In order to minimize the formation of local nonuniformity in the billets manufactured from low carbon and medium carbon steel, open cast by CCM, it is necessary to maintain a maximum [Mn]:[S] ratio with [Mn]:[Si] ratio at the level less than 2-3, which ensures the formation of fusible deoxidation products and prevents the formation of solid conglomerates in steel. In order to reduce the formation of axial porosity it is advisable to retain the carbon content at the lower limit for the steel grade and avoid overheating of steel above the specified values. In order to minimize the consequences of the overheated steel casting it is necessary to adjust the billet casting rate in accordance with the operating procedures.

Evaluation of the quality of cladding deposited on continuous steel casting rolls

2013 ◽  
Vol 104 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Ján Viňáš ◽  
Janette Brezinová ◽  
Anna Guzanová ◽  
Peter Balog
Keyword(s):  
Steel Casting ◽  
Continuous Steel Casting ◽  
Continuous Steel

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

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