ASTM B898 Overview
After extensive review and input from owner-operators, fabricators, clad manufacturers, and metal suppliers, ASTM’s B10 Reactive Metal Committee approved B898 in 1999. Today, B898 is the internationally recognized specification for clad plate made from a base metal – often steel – that has been metallurgically bonded to titanium, zirconium, tantalum, and niobium.
B898 applies to clad made by any cladding operation to produce a plate that will adjust to the specification requirements, including but not limited to explosion bonding, roll bonding and weld overlay. With a solid-state weld over at least 95% of the plate’s surface and bond shear strength of over 20,000 psi (140 MPa), fabricators have long relied on B898-compliant clad plates for pressure vessels and other industrial processing equipment, which increases the long-term viability, safety and reliability of oil & gas, chemical & petrochemical, power generation, and metals extraction & refining operations, and translates to lower costs over the equipment’s lifetime.
The B898 specification includes detailed technical requirements and added, yet optional, guidance for product quality and testing that, when followed, provide for durable applications that work without imposing unnecessary manufacturing costs and timeline delays on fabricators. Of all the tests, two recently underwent updates – the ultrasonic test and the shear strength test.
First, ultrasonic testing, was revised to a standalone test that includes a more detailed set up procedure coupled with apparatus information such as transducer size, frequency, and a dual, pitch-catch probe design type.
Second, shear strength testing, which measures a clad plate’s ability to withstand forces that cause the dissimilar metals to slide in parallel, opposite directions from one another, has an updated drawing.
By adhering to B898 requirements and partnering with a clad plate manufacturer who has onsite reactive metal testing facilities, large plate project timelines expedite without compromising material and application performance later.
When clad plate is marked with a B898-certified stamp, fabricators and owner-operators can be sure the clad has met rigorous requirements for chemical composition and mechanical properties, and the clad complies with NDE requirements, among others outlined in B898. The certification also verifies the clad plate orientation, thickness, tension, bend and impact testing has been completed in accordance with the base metal specification—and that the clad’s surface is free of excess imperfections and unnecessary materials.