1) acceptance testing of the billet;
2)*** – intensive active cold deformation of the billet using different deformation
schemes in a certain sequence;
3)
heating
– high-speed heating of the cold-worked billet;
4)
cooling
– quenching;
5)
ACD
– active cold deformation of the "hardened" billet;
6)
CD
– cyclic deformation;
7)
CD
– active cold deformation with manufacturing the product of final geometry
according to the deformation of the billet scheme;
8)
CD
– cyclic deformation of the cold-worked product;
9)
fnl.test.
– final testing and product certification.
Note: Also see the text on p.p. 14-15.
CONCLUSION
Comparative analysis of the known technologies for manufacturing hardened
steel products using the methods of heat hardening and the methods of
thermomechanical hardening shows that the developed technology favourably differs
from the others by using only one type of hardening – deformation, which gives better
logistics and ecology due to exclusion of the technological operations of high-
temperature heating and rapid cooling; reduces the price of the billet, since the cold
deformation does not require alloying; we may speak of the universal billet used for
manufacturing many types of the cold-worked products. The new technology in
comparison with the known ones can be attributed to energy-saving technologies by
the specific energy consumption, especially if we take into account the possibility of
reducing the cold deformation resistance and its degree. The essential advantage of the
new technology, as already noted above, is the principal possibility of organizing the
operational control of the process of structural state forming of the billet and the
finished product with the organization of 100% non-destructive testing of their
properties (increase in the nondefective yield, decrease in metal consumption). The
combination of the technological deformation with additional hardening of the product
and the possibility of giving the product a form at which the principles of geometric-
and-structural hardening are realized, gives significant advantages both in energy
consumption and in product properties [14]. Manufacturing a product of precise
dimensions with a low surface roughness additionally increases its operational
reliability, and the resulting structural state is one of the most important performance
characteristics – the resistance to cyclic loading [21].
If we outline the advantages of the new technology concisely, they are the
following:
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