Coated Sheet 


Terne Sheet and NI-TERNE Sheet
Fabrication Considerations

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.

Typical Applications Application Considerations Fabrication Considerations Tolerances