jiachuancasting Yeni Üye


Kayıt Tarihi: 2022-22-Nisan Ülke: Avustralya
Aktif Durum: Pasif Gönderilenler: 2
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Gönderen: 2022-22-Nisan Saat 11:53 | Kayıtlı IP
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casting/">Carbon cast steel is a kind of steel material,
and carbon is the main element that affects the mechanical
properties of carbon cast steel. With the increase of carbon
content, both the yield point and tensile strength of carbon
cast steel increased, and the tensile strength increased more
than the yield point. In addition, as the carbon content
increases, the ductility and toughness of carbon cast steel
decrease. When the carbon content in carbon cast steel exceeds
0.45%, the yield point rises very little, while the ductility
and toughness decrease significantly. As the carbon content
increases, the solidification temperature of carbon cast steel
decreases, and the fluidity and casting properties of molten
steel become better.
Compared with iron/">cast iron, carbon cast steel has poor casting
performance. Carbon cast steel has a high freezing point, poor
fluidity, large solidification shrinkage, and high inhalation,
so it is easy to form pores, sl*g inclusions, shrinkage holes,
looseness, hot cracking, cold cracking and cold insulation.
Higher casting temperatures can be used to improve fluidity, and
larger casting risers can be used to compensate for
solidification shrinkage.
Carbon steel castings are not suitable for direct use due to
their low as-cast plasticity and toughness. In order to improve
the properties of carbon steel castings, heat treatment is often
required to refine the grains, eliminate the Widmanstler
structure and casting stress, and improve the mechanical
properties. Carbon steel castings with complex shapes that are
prone to deformation and cracking should be annealed; carbon
steel castings with simple shapes and not too large wall
thickness should be normalized; carbon steel castings with
larger sizes generally use After normalizing, tempering
treatment; carbon steel castings with simple shapes and high
mechanical properties should be quenched and tempered. Annealing
or normalizing is generally carried out before the quenching and
tempering treatment, and some are directly quenched and tempered
in the as-cast state. The latter has the advantages of simple
process, short production cycle and low cost. During heat
treatment, the heating rate of carbon steel castings with large
size or complex shape should not be too fast, otherwise the
carbon steel castings will easily cause deformation or cracking.
The heating rate of large carbon steel castings is generally
limited to 50-100°C/h, and the small ones can be controlled at
100-200°C/h. The annealing and normalizing temperature of
carbon steel castings should be appropriately higher than that
of carbon steel hot-worked parts of the corresponding grades,
and the holding time should be appropriately longer to ensure
uniform composition and structure.
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