10…40%, the optimum value of which is determined in a series of preliminary
experiments, which together leads to dislocation fragmentation of the matrix within the
grains of the above size and, thus, forms the matrix (ferrite) dispersed on two
dimensional levels. It has been indicated above that the described dispersion of the
matrix at each of the used size levels favourably affects the level of cold resisting
properties in the cold-worked and then aged state. Therefore, if the degree of
deformation of the billet during the technological deformation of the finished product
manufacturing is relatively low (as, for example, the die-rolled section finish in the
production of cold-worked reinforcement), then this technological operation 6) follows
directly the technological operation 5), and the next is technological operation 7) cyclic
deformation of the finished cold-worked product and, finally, technological operation
8) final testing of the properties and product certification.
If, however, the deformation degree of the billet during the technological
operation 6) is sufficiently high, then variant V appears, which differs from variant IV
by introducing the technological operation 6) cyclic deformation of the cold-worked
billet according to the technological operating procedure 5), and only then occurs the
technological operation 7) cold deformation associated with manufacturing the product
of a given geometry, technological operation 8) – cyclic deformation of the finished
product, and technological operation 9) final testing and certification of the product.
Thus, it can be said that there are five variants of the technological schemes for
manufacturing steel products hardened by cold deformation, that are based on the new
principles of obtaining the structural state of steel using cold deformation. At the same
time, a unified approach can be used for all the developed variants, both for the
operational control of the structural state of the billet in the course of the technological
process, and for 100% non-destructive testing of properties of the finished products. A
detailed review of the principles for the application and organization of these types of
testing is beyond the scope of this article and is the subject of a separate description,
analysis and use, including the preparation of the applications for patents.
This article just substantiates the possibility of these or other testing methods and
the effects of their application for the developed technologies for manufacturing steel
products hardened by cold deformation.
The method for controlling the change in the structural state of a deformable metal
is based on the analysis of the spectrograms of ultrasonic emission of the deformable
object and the comparison of the "favourable" reference spectrograms with the current
ones, obtained directly in a particular case of deformation, where both the processes of
accumulation of dislocations in the metal and the formation of microcracks are
reflected [22].
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