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Actual Problems in Machine Building. 2015. N 2
Innovative Technologies
in Mechanical Engineering
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8. Adetunji O.R., Kuye S.I., Alao M.J., Eng B.M. Microstructures of mild steel spring after
heat
treatment
//
The
pacific
journal
of
science
and
technology
/
http://www.akamaluniversity.us/PJST.htm, 2/2013, p. 11-13
CONTROL STRUCTURE ON THE СAST OF RAILWAYS
Chertovskih E.O.
1
, Ph.D. student, e-mail:
chertovskih13@gmail.comGabets A.V.
2
, Ph.D. (Engineering), Development director,
Gerter M.V.
3
, Engineer, e-mail:
gerter-maksim@rambler.ru1
I.I. Polzunov Altai State Technical University, 46 Lenina avenue, Barnaul, Altai region, 656038,
Russian Federation
2
Altai Steel Casting Factory, 116/52 Kalinina st., Barnaul, 656037, Russian Federation
3
Test Center of Technical Equipment, 16 “22 Partszda” st., Novoaltaisk, 658087, Russian
Federation
Abstract
The paper describes an approach to controlled cooling of steel 20GFL, which further ensures the
formation of the expected structural components in the form of ferrite, pearlite, and lower and upper
bainite on heat treatment of large railway castings. Control of intermediate transformation of
austenite was carried out by recording the temperature and time of the front critical points Ar3,
Ar1where increasing the speed of intermediate transformation made it possible to form globular
coagulations of lower bainite. The use of controlled cooling showed decreased sensitivity to mild
steel casting defects in the form of liquation and segregation by forming a favorable structure of
lower bainite. An example of calculating the degree of deformation of t structure-forming elements
after impact tests is given.
Keywords
austenite, pearlite, ferrite, upper bainite, lower bainite, mezoferrit, toughness, mild steel