Special Features Of Structure Formation Research Articles

Special features of structure formation in sheet low-alloy steel heat treated under industrial conditions

Special features of structure formation in sheet low-alloy steel heat treated under industrial conditions

Structure and properties of the surface of iron-carbon alloys melted by laser radiation

The aim of the work consists in analyzing the special features of structure formation in melted zones (MZ) in laser treatment of iron-carbon alloys with a eutectic.

Special features of the formation of microstructure of heat-treated low-alloy steel

The strength and the operational properties of low-alloy thick-sheet steels is increased by heat treatment in the line of the mill with the use of the rolling or furnace heat. The present work concerns the special features of structure formation and the mechanical properties of rolled stock from sheet structural steel 09G2S with a strength level C345 (σy=325-345 MPa) in a hot-rolled and a normalized state after accelerated cooling from the normalizing furnace and after rolling behind the finishing stand. As a result of the rapid cooling in the line of the mill the sheet acquires properties corresponding to steels with a C390–C440 strength level (σy=390-440 MPa).

Special features of structure formation in and properties of the surface layer of steel irradiated by a beam of relativistic electrons

The effect of various regimes of electron-beam facing on the characteristics of the surface layer of steel is considered. The processes of electron-beam treatment in an accelerator of relativistic electrons and in vacuum are compared.

Special features of structure formation in the operation of unfired bottom articles

Tests of unfired chamotte articles for bottom steel casting prepared by the developed technology showed. their substantial advantages over fired refractories. The former have a high heat resistance and a low erosion. A petrographic analysis of bottom articles after service showed. the formation of a thermostable structure promoting high operational parameters.

Special features of structure formation in steels subjected to surface alloying

In the process of laser surface impregnation the thin surface layer of the molten metal is in contact with the solid metal of the substrate. Its structural components can play the active role of seed crystals determining the structure of the zone of secondary solidification. In order to investigate the effect of the structural and the phase states of the treated material on the processes of structure formation in the zone of laser effect the authors conduct a comparative x-ray phase analysis of different steels subjected to laser boronizing.

Special features of structure formation and atomistic aspect of the interpretation of solid phase reactions in porcelain

It is established on the basis of electrochemical analysis that solid-phase reactions occurring in firing of porcelain, namely, the formation of mullite in decomposition of kaolinite and crystallization of mullite in melting of feldspar, have a topotoxic nature and prove the theory of inheritance in crystalline structures.

Some special features of structure formation in sintering ultradisperse powders of TiN — AlN compositions

Regularities of compaction and changes in the pore structure of ultradisperse powders of pure TiN, AlN, and compositions based on them are investigated during sintering in a wide range of temperatures. It is established that the distribution of pores, against the background of the continuously decreasing total volume of them with increase in temperature, is close to unidimensional, and for an equivolume compositiondav is about 35 nm in a wide range of sintering temperatures. The latter effect can be used for practical purposes.

Special features of structure formation in activated sintering of chromium

Special features of structure formation in activated sintering of chromium

The swelling of filled styrene-divinylbenzene copolymers

IT IS now known that the addition of fillers to polymers, especially rubbers, results in additional network formation. In our earlier studies [1-3] we examined the effect of a filler on structure formation in thermoplastic polymers. Study of the special features of structure formation in the case where formation of the polymer takes place simultaneously with formation of the final material is of great interest. Investigation of the conditions of formation of a crosslinked polymer in the presence of a filler would be of great value, particularly to the production of reinforced plastics. We have previously shown that the structure of a linear polymer formed in the presence of a glass surface differs from the structure of the polymer produced in the absence of a filler [4, 5]. The aim of the present work was to discover some of the specific features of formation of a crosslinked polymer in the presence of glass powder of small particle size. A number of papers has been concerned with the s tudy of polymer networks formed in the presence of a filler [6-11]. The materials studied in these papers were exclusively vulcanizates of natural and synthetic rubbers--butadienestyrene, polyurethane etc. In these studies the kinetic theory of elasticity and the F lory-Rehner theory of swelling [12] formed the basis for investigation of the behaviour of the networks in the presence of a filler. By making use of the well known equation of the latter theory, and making a number of assumptions, it is possible to arrive at an estimate of the number of crosslink points in the network of the filled vulcanizate, and thus to estimate the number of additional points of crosslinking due to polymer-filler interaction. I t seemed of interest to apply the theory of the swelling of filled vulcanizates to the swelling of filled, erosslinked polymers that are not in the high-elastic state under the experimental conditions.