ASTM A48 Class 25 Cast Iron
ASTM A48 class 25 is a material grade of
gray cast iron in USA, which is higher than class 20, but lower than
class 30. Its UNS number is F11701. There are four specific grades
as ASTM A48 class 25A, 25B, 25C
Mechanical Properties of A48 Class 25 Cast Iron:
Its minimum tensile strength is 172 Mpa.
The gray cast iron is
brittle, so there is no requirements to yield strength and
elongation. Its hardness range is BH 170-229.
Although gray iron has bad tensile
strength, but their production costs are low, and easily
manufactured, moreover, this material has good Vibration reduction,
abrasive resistance, and low notch sensitivity. In addition, they
could be machined easily.
Chemical Composition of A48 Class 25 Cast Iron:
C%: 3.20-3.50, Si%: 1.60-2.40, Mn%: 0.60-0.90, P% ≤ 0.20, S% ≤ 0.15,
We have talked about this issue for many
times in the past. In all international standards, there is no
compulsive stipulation to the chemical composition range. This is
very different with cast steel. As for gray iron and ductile iron,
the chemical composition is just for reference. The iron foundries
could adjust the composition as long as the mechanical properties
could meet the requirements.
Heat Treatment of ASTM A48 Class 25 Gray Iron:
The heat treatment can not change the structure of graphite, so can
not improve their mechanical properties, however, the annealing
treatment could reduce the internal force, and chilling
organization, stable the deformation, and improve the abrasive
resistance. However, the heat treatment will cause more production
costs, so most of grey iron castings will not be heat treated,
unless some special application.
Main Application of ASTM A48 Class 25 Gray Iron:
Class 25 gray iron could be used to produce casting parts as machine
base, frames, supports, cases, machine body, bearing support,
foundation plates, belt pulley, end caps, pump bodies, valve bodies,
pipe fittings, fly wheels, gears etc.
The followings are some casting products
manufactured by our iron foundry.