Fabrication Conditions A Determinant In Steel Weldability

The ability to join two pieces of metal together using heat has been known to mankind for thousands of years, and archeologists have actually discovered jewellery with forge-welded joints. Of course, a lot of development and innovation has taken place since those ancient times, and we now have the welding technology available to build huge structures such as dams, bridges, transmission towers, skyscrapers and pipelines traversing thousands of kilometers. Today welding is used in the fabrication of every metal product, and cellulosic manual metal arc welding, which was developed in the 1920s, is still used in pipeline steel pipe welding in Australia.

The Australian pipeline industry relies on steel manufacturers to understand fabrication conditions in developing steel products suitable for use as steel pipe Brisbane. This is because there are three things to address when using welding as a construction technique, one of which is the conditions under which the fabrication will take place. The other two considerations are the weldability of the steel itself and its performance in service.

In terms of pipeline construction, the ability of the steel to be welded successfully, or its weldability, is the heart of the construction process. However, within the industry, this is a term that is fairly generic and can have different meanings depending on the context. To clarify this issue, the Australian Standards set down a definition specific to the pipeline steel pipe welding process, and this is where the three considerations mentioned above originate from.

Dealing further with the first consideration, i.e. the conditions under which fabrication will take place, it must be remembered that this will vary with almost every project. For example, many pipeline projects will be partially completed in an engineering facility, then transported to site for final welding, while some projects will be fabricated completely on site, with welding taking place in remote locations such as the middle of a desert, or a jungle-covered region in the tropics.

These conditions will determine the type of steel that will be used. Some steels can only be welded under controlled conditions in a workshop, but pipeline steels must have weldability under typical fabrication conditions. These conditions include being able to weld in all positions around the pipe using cellulosic electrodes, no necessity to preheat, adverse loadings and demanding production standards.

In typical pipe fabrication projects, experienced welders are accustomed to working in these conditions, and are able to continuously extend the length of the pipeline to meet the production deadlines. The other two considerations that combine with fabrication conditions to meet the standard definition of weldability should also be examined to get the full picture.

The three conditions must be present to ensure that a finished pipeline will meet all design and manufacturing standards, and operate in accordance with specifications. The weldability of the steel itself, and its performance in service are the two remaining conditions that determine overall weldability.