A nickel-iron-chromium grade, RA330® offers an exceptional combination of strength and resistance to carburization, oxidation and thermal shock.
RA330® was created to service the needs of the thermal process industries with a reliable source of a wrought product that could handle high temperature carburizing and nitriding conditions with repeated quenching. RA330® has excellent oxidation resistance up to 1148°C.
| % | Cr | Ni | Si | C | Mn | P | S | Cu | Fe |
|---|---|---|---|---|---|---|---|---|---|
| Min | 18 | 34 | 1 | - | - | - | - | - | Balance |
| Max | 20 | 37 | 1.50 | 0.08 | 2 | 0.03 | 0.03 | 1 | - |
The chemical composition of RA330® has changed over the years to allow for improved performance in the thermal process industry.
RA330® is the workhorse of the heat resistant alloys with good strength and oxidising resistance up to 1148°C. In addition, the alloy is excellent in carburizing and nitriding environments.
The properties of RA330® are enhanced by a nominal 1.25% silicon addition. It has been designed to withstand thermal shock induced by liquid quenching.
RA330® finds wide applications in high temperature environments where good resistance to the combined effect of carburization and thermal cycling conditions are the prime requisite.
RA330® remains fully austenitic at all temperatures so it is not subject to sigma embrittlement. It is highly resistant to chloride-induced stress corrosion cracking and thus an alloy of choice where common stainless grades have failed by stress corrosion cracking.
RA330® can be fabricated and machined using procedures used for stainless steels or nickel-chromium alloys. Heat treatment is not necessary after most forming and welding operations. When required, the recommended full anneal is 1038-1371°C, rapid air cool or water quench. RA330® can be readily welded using RA330-04® or other weld fillers of matching conditions.
RA330® is the registered trademark of Rolled Alloys Inc.
| Mechanical & Physical Properties | 21°C | 538°C | 593°C | 649°C | 704°C | 760°C | 816°C | 871°C | 982°C | 1093°C |
|---|---|---|---|---|---|---|---|---|---|---|
| Ultimate Tensile Strength /MPa | 586.1 | 489.5 | 457.8 | 390.9 | 305.4 | 247.5 | 184.8 | 145.5 | 71.7 | 22.1 |
| 0.2% Yield Strength /MPa | 268.9 | 172.4 | 166.9 | 151.7 | 144.8 | 142.7 | 119.3 | 106.2 | 58.6 | 13.8 |
| Elongation | 47 | 46 | 46 | 43 | 69 | 78 | 56 | 79 | 79 | 28 |
| Minimum Creep 0.0001% per hr /MPa | - | - | - | - | - | 24.8 | - | 14.5 | 3.4 | - |
| 10,000 hr Rupture Strength/MPa | - | - | - | - | 29.6 | - | 11.7 | 4.3 | 1.9 | |
| Coefficient of Thermal Expansion /µm/m⁰C | - | - | - | - | - | 17.46 | - | 17.64 | 18 | - |
| Thermal Conductivity /kcal/(hr.m.°C) | 10.71 | - | - | - | - | 20.39 | - | 21.13 | 21.87 | - |
| Modulus of Elasticity / x105 MPa | 2 | - | - | - | - | 1 | - | 1 | 1 | - |
Proud members of the British Valve & Actuator Association