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.
We stock RA330® in a variety of product forms to suit different applications and fabrication methods, including coil, expanded metal, seamless pipe, pipe fittings, plate, round bar, sheet, welding electrode and welding wire. To view available sizes and submit an inquiry, use the dropdown selector below.
| % | 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 | - |
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