Is There a Welding Code for Structural Welding of Aluminum?

Know More About Welding Code for Aluminum

- I have a welding shop that manufactures small to medium-sized welded structures. I have been acquiring some larger contracts lately in both steel and aluminum structures. Some of my larger steel customers have requested that we have welding procedures and qualified welders for some of the structural steelwork. We have used AWS D1.1 Structural Welding Code – Steel to qualify our procedures and welders for steel.

- I am currently trying to increase the amount of aluminum fabrication business and think that I should consider the possibility of producing welding procedures and qualifying my welders for aluminum. Is there a welding code like AWS D1.1 that can be used for aluminum? If so, can I transfer my D1.1 procedures and performance qualifications from steel to aluminum?

Yes, there is a welding code like AWS D1.1 that can be used for welding aluminum. It is AWS D1.2 Structural Welding Code – Aluminum. However, you cannot transfer your procedures and performance qualifications from steel to aluminum. If you want to qualify welding procedures and welders for aluminum welding, your employees will have to seek this qualification independently from their current steel qualification.

The History Behind the Welding Code for Aluminum

AWS has been developing codes for the welding of various steel structures since 1928. In the early 1970s, the need for developing a code for the structural welding of aluminum was recognized. Because of the interest of both The Aluminum Association and AWS, the task of developing a structural welding code for aluminum began in the mid-1970s.

Initially, a task force from The Aluminum Association undertook the effort. In 1979, this task force became a subcommittee of the AWS Structural Welding Committee, and the D1.2 Structural Welding Code – Aluminum resulted from the continued activity of that subcommittee.

The welding code for aluminum structures is AWS D1.2 Structural Welding Code – Aluminum. In many ways, this code is similar to the AWS D1.1 document. However, the similarity of D1.2 to D1.1 is only in format, which has been chosen to match D1.1 for its simplicity of use, especially for welders who use both codes.

However, the two codes are completely independent. This is because of the different characteristics of steel and aluminum relating to their metallurgical structure and reactions during welding, method of welding, design criteria, and inspection and testing requirements.

About AWS D1.2 Structural Welding Code – Aluminum

The current edition of AWS D1.2 is the 2014 edition. This document, divided into sections and annexes, covers the welding requirements for any structure made from aluminum structural alloys, except for aluminum pressure vessels and pressure piping. Let us look into them. 

1. Clauses 1 through 8 constitute a body of rules for regulating welding in an aluminum construction. A commentary on the code is also included in comprehending the code's application.
2. Other sections contain additional rules applicable to specific types of non-tubular and tubular structures and should be used as a supplement to the beginning sections. Key features of each of these sections are the list of dimensional tolerances and the weld quality requirements.
3. These are provided for non-tubular structures under static and dynamic loadings. For tubular structures, two classes of structures are identified. Class I structures are those in the general class of luminaries, traffic signals, and overhead sign supports. All other tubular structures are class II. Many of the requirements (dimensional and weld quality) are more stringent for class II structures.
4. Recommended joint details have been prepared for various complete joint penetration and partial joint penetration groove welded joints. In fact, this is one of the major differences between the Structural Welding Code – Steel and the code for aluminum.
5. While the steel code allows for prequalified welding procedures, the code for aluminum does not. This is because of the many and varied possible welding conditions that can be obtained with the semi-automatic welding variables most often used with aluminum.
6. It’s also due to the wide range of both heat-treatable and non-heat-treatable alloys that may be welded under this code. Therefore, all of the joint details and the welding procedures used with the code should be individually qualified and included in the Welding Procedure Specification (WPS).
7. Procedures and standards are also outlined in the code for several methods of nondestructive testing. Methods included are visual, radiographic, and dye-penetrant. Ultrasonic testing is permitted, but the procedure and acceptance criteria must be specified in the contract documents.
8. Unlike the steel structural code, D1.1, the aluminum structural code, D1.2, does not cover design considerations, such as the allowable stresses for load-carrying members. This information is covered by reference to the Aluminum Design Manual, published by The Aluminum Association.

Why These Codes Are So Important

Working with a welding code or standard for any material is important. It provides an opportunity for the welding fabricator to control quality and improve the reliability of their product. If more manufacturing organizations moved toward the implementation of quality management systems, such as ISO 9000, then welding should also have formal controls.

Like ISO 9000, welding codes and standards can be used by the welding fabricator to assist with the development of their process control system. If you look at the major elements of process control, you’ll notice:

• The first requirement for process control is to have documented procedures defining the manner of production. For welding aluminum, this is the welding procedure specification (WPS).
• The second requirement is criteria for workmanship, which should be stipulated in the clearest practical manner. For welding aluminum, this may be the code or standard quality acceptance criteria.
• The third requirement is the qualification of personnel. For welding aluminum, this is addressed by the code or standard welder performance qualification test.

In adopting a welding code or standard, you can achieve these three main elements of a welding control system. This provides reassurance that the fabricated product has been manufactured in accordance with a nationally recognized standard. It will also be invaluable if you should ever have to defend the integrity of your welded product.