The 1953 introduction of RA330
In 1953, when Rolled Alloys was founded as an independent company, RA330 was introduced as a wrought alternative to cast HT, which at the time was a 35% Ni, 15% Cr alloy. In 1958, the chemistry was modified by lowering the carbon to 0.08% maximum, while increasing the chromium to the present nominal 19% to maintain strength. At the same time the silicon range was tightened to its current 1.00 to 1.50%. In 1975, RA330 was granted ASME code case approval (1654-1) for use to 800°F, and several years later, approval was granted for use up to 1650°F. The current chemistry of RA330 is shown below.
Despite its age, RA330 is a versatile alloy, which facilitates its use in many applications in heat treating and other industries. With 35% nickel, it is not subject to sigma phase embrittlement. This nickel content is sufficient for resistance to carburization and nitriding. With relatively low carbon and the nickel content, there is sufficient ductility for thermal fatigue resistance. The alloy shows excellent resistance to oxidation up to 2100°F and useful creep strength to 1850°F. All these features make RA330 the preferred alloy choice for heat treating applications, at a relatively low cost. It is also available in a wide range of sizes and shapes for quick delivery. Compared to alloy 600 and 601, RA330 is more economical and is readily available. Rolled Alloys also stocks RA330-04 welding consumables for most types of welding.
With all of these attributes, RA330 has become the primary choice for heat treating rod baskets, heat treating fixtures, retorts, electric element tubes, muffles, corrugated boxes, pearlite expander tubes, flare tips, tube supports, tooling for glass making, and many other specialized applications.
RA330 is in stock and available in plate, sheet, round bar, pipe, expanded metal, fasteners, and welding consumables. In addition, the Rolled Alloys Metallurgical Services (RAMS) team is available during business hours to help answer your questions about RA330.
RA330® is a registered trademark of Rolled Alloys.