Weldability of A588 Grade A Weathering Steel

Welding A588 Grade A steel is a high strength, low alloy (HSLA) steel that is highly formable and often used in structural applications. The most common grade of A588 is A588 Grade A. The grade is rated very highly due to its excellent weldability, high tensile strength, and superior corrosion resistance.

Welding A588 Grade A steel is not an easy task. It has a higher-than-normal carbon content and higher mechanical properties, as well as its own unique chemical composition, which needs to be taken into account when welding. As with all HSLA grades of steel, A588 Grade A is prone to hot cracking during welding, which can be avoided with pre- and post-heat treatments. Pre-treatment involves heating the steel over the range 350-400°C for a period of time to soften the material and stress relieve it. Post-treatment involves tempering the steel to a lower temperature than pre-heating to relieve any residual stresses in the steel.

In addition to pre- and post-heat treatments, there are other techniques that can be used to increase both the weldability and the mechanical properties of A588 Grade A steel. These techniques include the use of flux-cored or metal-cored consumables (FCAW and MCAW, respectively) in place of the SMAW or GTAW. These techniques increase the dilution of the weld and the volume of deposited weld metal, resulting in improved weld strength. FCAW and MCAW also have higher deposition rates and are less expensive, making them more economical for most projects.

Another factor to consider when welding A588 Grade A steel is the type of joint used. Butt-joints should be avoided for A588 Grade A steels, as they are prone to hot cracking. As an alternative, T-joints should be used. They have a smaller thermal stress field and are capable of withstanding higher heat inputs.

In addition to ensuring proper joint design and welding technique, correct welding parameters are also important for successful welding of A588 Grade A steel. This includes the use of a low heat input and a relatively slow travel speed. A proper electrode size should also be selected, based on a number of factors including the thickness of the material and the amount of weld being deposited.

A588 Grade A steel is a highly formable and weldable grade of HSLA steel. However, it does have some unique properties relative to other HSLA grades, which should be taken into account when welding. Proper pre- and post-heat treatments should be used, as well as the proper welding techniques and parameters. Taking into account all of these factors will ensure the successful welding of A588 Grade A steel.