RA333® (UNS N06333)
RA333® is a high chromium nickel base superalloy with outstanding resistance to high temperature oxidation and carburization. RA333 has an exceptional ability to withstand the repeated thermal shock of oil or water quenching. RA333 is one of the few materials that can withstand corrosive conditions ranging from aqueous to white heat. Upon shutdown, RA333 resists dew point corrosion by sulfuric acid and polythionic acid stress corrosion cracking.
Weld RA333 with matching composition N06333 bare wire or RA333-70-16 AC/DC coated electrodes. Do not preheat, keep interpass temperature below 212°F and use reinforced stringer beads. Machinability rating of RA333 is 12-15% of B1112; turn 20-25 sfm with high speed steel tools.
AMS 5593, AMS 5717
ASTM B 718, ASTM B 719, ASTM B 722, ASTM B 723, ASTM B 726
W. NR./EN 2.4608
RA333® Plate, RA333® Welding Products
Common Trade Names
- Tube supports in refineries and coal fired boilers
- Heat treating muffles, retorts, fan shafts and fixtures
- Carbon Fiber production muffles
- Sulfuric acid plant stack dampers
- Molten glass spinnerets
- Flare tips
- RA333 weld filler for repair welding of cast heat resistant alloys
- Tire Drop Chutes for Cement Kilns
RA333 was originally developed to withstand high temperature carburizing service. It is one of the most carburization resistant materials available. Because of this ability RA333 has been the choice for all types of applications that require heavily carburizing atmospheres. Fabrications including radiant tubes, corrugated boxes and furnace belt pins have all been made from RA333 to withstand the high carbon potentials within these atmospheres. Resistance to metal dusting environments can be attributed to the alloying elements of silicon and tungsten. Simply having a high temperature alloy with chromium and nickel without these elements would be insufficient for a metal dusting application. Along with alloy chemistry, metal dusting resistance is influenced by grain size. A finer grain size greatly increases the rate at which chromium can diffuse to the surface to form a protective film.
310 stainless flight corroded in between two RA333 weld beads in a metal dusting atmosphere.