Welding
Weathering Steel is readily weldable by the submerged-arc, shielded metal-arc, gas metal-arc, and flux-cored arc welding processes.. Procedures are similar to those used for other low-alloy structural steels. Low-hydrogen electrodes are specified by the American Welding Society for welding Weathering Steel. Suggestions on minimum preheat are contained in the ANSI/AWS 'Structural Welding Code" D1.1-92, and the ANSI/AASHTO/AWS "Bridge Welding Code" D1.5-88.

For bare steel applications when the weld is required to have strength, corrosion resistance, and weathered appearance similar to that of the base metal, special electrodes must be used.

When matching strength is the only requirement and color match and corrosion resistance are not important, E70, E80, E90, E100 or E110 low-hydrogen electrodes may also be used. These electrodes may also be used for the underlying passes in multiple-pass welds. However, when color match and corrosion resistance are required, appropriate alloy electrodes must be used for the final two exposed top layers.

All welding should be consistent with AWS recommended procedures including adequate edge preparation and preheating, the selection of proper flux (when applicable) , and the use of properly dried, low-hydrogen electrodes and fluxes.

Oxygen Cutting
Weathering Steel can be cut with conventional oxygen-gas equipment employing the same general procedures used for other structural steels. The workmanship requirements outlined in ANSI/AWS D1.1 and ANSI/AASHTO/AWS D1.5, Part 3 should be observed.

Mechanical Fasteners
Fasteners used to join or attach Weathering Steel should provide a corrosion resistance and weathered appearance comparable to that of the base material. High-strength structural bolts, including appropriate nuts and hardened washers, are available in Weathering Steel.

However, it may be desirable in certain circumstances to use another type of fastener. Galvanized fasteners have been used in some applications, such as highway guardrail. Whereas fundamental electrochemical and thermodynamic considerations would lead one to predict a decreased life of the galvanized coating, this does not appear to be a limiting factor. Part of this success can be attributed to the thick coatings applied in hot-dip processing-typically 3 to 5 mils-giving a long life expectancy. A light colored stain on the weathering steel just beneath the galvanized fasteners, which results from the rundown of zinc corrosion products, should be considered if appearance is critical.

In bolted connections, the space between two surfaces of Weathering Steel will usually seal itself with the typical tight oxide if the joint is tight and immobile. If the joint will have some movement, both surfaces should be coated with protective material and filled with a suitable sealant to avoid progressive corrosion.

Bolt Spacing
In making an riveted, bolted or welding joint, fastener spacing should be such that the joint is tight and moisture cannot enter between the plys of material. If moisture enters the joint, corrosion may cause prying of the joint ( also called "packout") or fastener failure. AASHTO provides guidelines with respect to fastener patterns and spacing to prevent his problem.

Overlapping Surfaces
In overlapping joints, such as those common in utility distribution poles and high mast light poles, water can be drawn into the joint area by capillary action. This will cause a breakdown of the normal oxide formation and "pack rust" will form. These joints should either be sealed to prevent water intrusion or the lap area contact surfaces should be coated to prevent rust formation.

Forming and Fabricating
Weathering Steel can be fabricated with conventional equipment, tools, and methods normally used for other steels with the same strength level.

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