Forming
| Joining
| Painting
Forming
U. S. Steel Terne Sheet and U. S. Steel NI-TERNE
Sheet is well suited to drawing and forming. In fact, the soft
lead-tin coating acts as a lubricant, often giving the sheet better
drawability than uncoated sheet. The superior ductility of the
terne coating allows this coated steel product to be used for very
deeply drawn parts. Through the years, this attribute of terne coated
steel sheet has allowed the automotive companies to fabricate very
intricately drawn fuel tanks.
Joining
Soldering
Terne sheet and NI-TERNE sheet can
be readily soldered with non-corrosive fluxes applying normal
procedures. Because it is essentially pre-soldered by the lead-tin
coating, terne coated sheet is frequently chosen for applications where
ease of soldering is an important manufacturing consideration. After
soldering is completed, the flux residue should be removed to prevent
corrosive damage to the coating.
Welding
Terne sheet and NI-TERNE sheet can be
readily welded by various methods. The method most frequently employed
is seam welding. This commonly used welding method has proven to be very
reliable in that weld failure in seam-welded fuel tanks has never been a
significant problem.
As with all coated steels, the welding of
terne coated sheet requires some adjustment of welding parameters from
those applicable to uncoated carbon steel. Care should be taken to
minimize damage to the terne coating so that the corrosion
characteristics are not adversely affected. Waxes or paints are
sometimes used on seamed areas to protect the coating.
Painting
Terne sheet and NI-TERNE sheet can be
readily painted by either continuous coil line prepainting or
post-fabrication spray-painting techniques. The excellent
paint-adherence characteristics of the lead-alloy surface allow painting
with conventional materials, equipment and systems.
Many types of paint are compatible with
the terne-metal surface for painting after fabrication. Often, no primer
or pretreatment is needed. Only the usual removal of dirt, oil,
grease or other contaminants is required. When U. S. Steel Terne
Sheet or U. S. Steel NI-TERNE Sheet is to be painted, it should
not be ordered with a chemically treated surface unless tests are
conducted to confirm that the chemical treatment does not adversely
affect the paint adhesion. It should be ordered dry or with oil only.
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