1 results listed
The results of modelling of temperature
fields, kinetics of deposition of layers of dissimilar metals
and nature of structural transformations in formation of
multi-layer structure of 17G1S and 30KhGS steels are
presented. Computer modelling was performed using
COMSOL Multiphysics package. The work takes into
account effect of temperature on thermal and physical
parameters of steels. To increase productivity of additive
process the work has studied simultaneous effect of 3 arcs
on process of deposit formation, kinetics of structural
transformations and diffusion processes of alloying
elements redistribution. The calculations show that
preheating of the substrate by arc in the beginning of the
process before application of deposited material is
necessary in order to decrease a stress level between
additive deposit and substrate to 50 MPa. It is shown that
the time of passing between neighbor arc heat sources
shall be kept in 5- 30 s range. It is determined that low
power of arc (1 kW) mainly provokes formation of
ferrite-bainite structure in the deposit, portion of bainite
in which makes 71 %, ferrite 28% and martensite 1%.
Application of larger power arc (5 kW) forms in the
deposit bainite-martensite structure, portion of bainite in
which makes 50%, portion of martensite rises up to
40% and that of ferrite to 10%. Increase of arc power
results in rise of maximum temperature of liquid pool to
1750-1850 C, growth of cooling rate to 15 – 25 C/s , and,
as a consequence, increase of martensite portion in the
structure of deposited layers. Developed software can be
used for mathematical modelling of metallurgical additive
process of formation of products from different steels,
titanium, aluminum etc. alloys.
International Iron & Steel Symposium
UDCS
КОSTIN V.A
LAUKHIN D.V
ROTT N.O.