AISC


8.7. Other General Information

8.7.1. When a box of welding electrodes is opened, what precautions are required for their protection from contamination?

From AWS D1.1:2004 Sections 5.3.1.4 and 5.3.1.5, “Welding consumables that have been removed from the original package shall be protected and stored so that the welding properties are not affected. Electrodes shall be dry and in suitable condition for use.” In addition, AWS D1.1:2004 Section 5.3.2 contain provisions for storage and baking for low-hydrogen electrodes, which are more susceptible to moisture absorption.

last modified 1 January 200

8.7.2. When dual-certified material (i.e., A36/A572 Grade 50) is specified, should welding be performed in accordance with AWS Group I or Group II requirements?

ASTM A36 steel is classified as AWS Group I material and, as such, may be welded with non-low-hydrogen processes. In contrast, ASTM A572 Grade 50 steel is classified as AWS Group II material, which, because of its higher yield strength, must be welded using low-hydrogen processes. Because dual-certified steel, by definition, meets the chemistry and strength requirements of ASTM A572 Grade 50 steel, welding should be performed using low-hydrogen processes, unless the suitability of an appropriate weld procedure specification using a non-low-hydrogen process can be demonstrated through qualification testing.

last modified 18 September 2002

8.7.3. How are seal welds sized and made?

Seal welds are sometimes made to provide a water- or air-tight joint that otherwise would not be. In building construction, seal welded joints are rarely required to withstand internal pressures as would be common in steel tanks and piping circuits. Consequently, they can be sized for any load transfer requirements or from minimum size requirements in AWS D1.1. 

An alternative to seal welds is to caulk with a clear silicone to keep water out.

In most case, seal welds commonly assume a fillet weld profile. Any aesthetic requirements for seal welds should be specified in the contract documents.

last modified 1 January 2006

8.7.4. Is steel in older existing structures weldable?

Possibly. If the chemical properties of steel to be welded are known, either by valid mill certification or by laboratory sample testing, its weldability can be judged by computing the carbon equivalent value. A more obvious approach would be to examine the existing structure for evidence of original welding. Alternatively, an on-site investigation could be performed to address weld ductility and base-metal hardening. Other factors should also be considered, such as past history of the structure, the nature of the loads, weather conditions, and whether the members to receive welds are loaded; refer to Ricker1.

[1]Ricker, D.T., 1988, "Field Welding to Existing Structures," Engineering Journal, Vol. 30, No. 1, (1st Qtr.), pp. 44-55, AISC, Chicago, IL.

last modified 18 September 2002

8.7.5. The term matching weld metal is used in the 2005 Specification Section J2. To what are these weld metals matched and in what document are the matching weld metals defined?

Weld metals are matched to the steel grade being welded. Matching weld metals are specified in AWS D1.1:2004 Table 3.1.

last modified 1 January 2006