Machinability of A588 Grade A Weathering Steel sheet

Machinability of A588 Grade A Weathering Steel

A588 Grade A is a weathering steel, otherwise known as a high-strength low-alloy steel, which was developed to eliminate the need for painting. The name of the steel originates from its primary use—building structures exposed to weathering elements, such as bridges, skyscrapers and outdoor monuments. This type of steel is considered to have superior strength and corrosion resistance when compared to traditional carbon steels. A588 Grade A is an essential alloying element in many industries, mostly due to its machinability.

The machinability of A588 Grade A weathering steel can be characterized as good, although slight adjustments in cutting speeds, feed rates, and tool selection must be considered when machining this steel. The weathering steel’s unique chemical composition, which includes copper, nickel, and chromium, makes it difficult to machine compared to traditional carbon steel. However, with careful planning, machining A588 Grade A weathering steel is fairly straightforward.

The machinability of A588 Grade A weathering steel can be further improved by preheating to around 200-250˚F (93-121˚C) prior to machining and then cooling with an external coolant, when possible. This helps to reduce the amount of “work hardening” of the steel during the machining process. Work hardening occurs when a workpiece is subjected to repeated incidences of plastic deformation during machining, which makes it increasingly more difficult to cut. By preheating the steel and cooling it with an external coolant, the risk of work hardening is reduced.

For drilling, reaming, tapping, and other machining operations, it is best to use cutting tools made of high-speed steel or cobalt steel. Carbide-tipped tools should also be considered. In general, carbide-tipped tools are considered to be more durable, as they are better able to withstand the steel’s high hardness as well as cutting forces. Regularly sharpened cutting tools and properly set speeds and feeds are essential to achieve the best machining performance. Additionally, a light cutting oil should be used any time tools are drilling, reaming, or tapping. The oil helps the tools to better penetrate the steel and cool the area being machined.

When cutting A588 Grade A weathering steel, it is important to take into account the varying degrees of hardness of the alloy, as it will have a direct effect on the cutting performance. Additionally, a factor of safety should always be taken into consideration when machining this steel.

In short, machinability of A588 Grade A weathering steel can be considered good, but some extra planning and consideration should be taken into account when preparing to work with this material. By preheating the steel and using the correct cutting tools, speeds, feeds, and lubricants, one can expect to achieve excellent results when machining A588 Grade A weathering steel.