Cold Forming EB-450 Plate
The high inherent toughness of EB-450 makes it
possible to cold form the steel at full hardness. EB-450 is best formed with the bend axis transverse to the grain direction of the original mill plate. Press brake bending should be reformed to a minimum inside radius of 5T across the grain and of 12T with the grain direction. AWT indicates the grain direction on
plates by painting a white arrow.
Cold forming to a 90° bend in a single stroke
is generally not recommended. In cold forming that requires bending 90° or more, incremental bending techniques are best. For incremental bending, a 1/2" thick plate for example would be cold formed in a press brake using a 4" diameter bottom die and a 5/8" radius punch. The punch would be impressed upon the plate along parallel forming sites approximately 1-1/8" apart. In this manner, the forming stresses are more uniformly distributed throughout the bend area. For workpiece sections with less that 12" of bend length, reduced forming radii may be used.
The high yield strength of EB-450 requires that
allowance for "spring-back" must be a consideration in cold forming. All flame cut edges should be ground and corners removed before bending.
Hot Forming EB-450 Plate
Hot forming of EB-450 can be performed for
bends too severe to be cold formed. Hot forming may be done in rolls or by press brake. he steel should be heated to 1600°F minimum before forming. Since EB-450 is not air hardenable, full hardness will not be regained after forming without requenching and tempering. For this reason, Astralloy-V®
plate is normally recommended for tight bends.
If EB-450 is quenched, prolonged heating in the
austenitizing temperature region should be avoided or a protective environment should be used to prevent excessive decarburization. Excessive decarburization reduces wear resistance.
In order to estimate the hardness to be
expected after hot forming EB-450 plate without reheat treating, AWT performed a study. A 1-1/2" thick sample of EB-450 was heated to 1650°F and held for 1-1/2 hours and still air cooled. The resulting hardness was measured to be 341
BHN on the surface and 331 BHN throughout the section.
Product Information
Product Specifications
Welding Guidelines
Machining
Heat Treating
Cutting
Printable Specs Sheet
