AR550

AR550 is an abrasion-resistant steel grade in the AR family, designed for high wear resistance in material-handling and mining applications. The AR naming convention denotes abrasion resistance, while the 550 suffix indicates a high level of hardness relative to lower AR grades; the material is typically specified with a nominal hardness around 550 on the Brinell scale. Produced by various steel mills, AR550 is commonly supplied as plates and sometimes sheet products used where wear from abrasive particulates is a major concern.

Mechanical properties vary by producer and heat treatment, but AR550 is intended to offer a balance of hardness and toughness suitable for wear parts. It provides excellent resistance to gouging and abrasion from hard rock and other particulates, while retaining adequate impact strength in plate form.

Processing and fabrication: AR550 plates are usually processed by standard steel manufacturing routes and can be cut, formed, and welded with appropriate care. Because of the high hardness, fabrication often requires preheating, controlled heat input, and post-weld heat treatment, as well as the use of low hydrogen filler metals to minimize cracking.

Applications: The grade is widely used for wear parts in mining and construction, including liners, chutes, dump truck bodies, excavator or loader buckets, and wear plates in conveyors and hoppers.

Limitations: While very wear resistant, AR550 can be tougher to form and weld than lower-hardness steels and may exhibit reduced toughness at very low temperatures. Designers select AR550 when wear resistance is prioritized over maximum ductility.