Haynes 230 is a superalloy used in aerospace applications. Melting point: 1,301 °C. Tensile strength: 860 MPa.
Haynes 230 is a heat-loving metal designed to stay strong and resist burning up at temperatures that would soften ordinary steel. It is one of the alloys helping a new generation of 3D-printed rocket engines survive the inferno of launch.
Quick facts
- Designation: UNS N06230, sold as “HAYNES 230”
- Maker: Haynes International
- Type: Nickel-based superalloy (a metal blend built to keep working at extreme heat), strengthened by mixing in other metals
- Main ingredients (by weight): about 57% nickel, 22% chromium, 14% tungsten, 2% molybdenum, plus small amounts of iron, cobalt, and a tiny 0.02% pinch of lanthanum
- Sustained service temperature: up to about 1149 C (2100 F)
- Melting range: 1301-1371 C (2375-2500 F)
- Density: about 8.97 g/cm3 (0.324 lb/in3)
What it is and how it works
Haynes 230 is a “solid-solution-strengthened” alloy. That means its strength comes from dissolving large, heavy atoms of tungsten and molybdenum into the nickel, where they get in the way of the metal’s internal structure shifting under heat. Think of it like dropping boulders into a flowing river: the metal can no longer creep or slide apart easily when it is glowing red-hot. This is different from many turbine-blade alloys, which instead rely on “precipitation hardening” (tiny particles that form inside the metal).
To keep from burning up, the chromium forms a tough, tightly bonded skin of chromium oxide (Cr2O3) on the surface, topped by a manganese-chromium layer called a spinel. This skin seals the metal against further oxidation, the chemical “rusting” that happens when hot metal meets oxygen. The tiny lanthanum addition acts like glue, helping that protective skin stick instead of flaking off as the part heats and cools. A controlled amount of carbon forms stable carbides that pin the metal’s grains in place, so it keeps its fine internal structure and toughness even after long, hot use. In plain terms: it stays strong, does not scale or burn, and does not turn brittle when held near 1000 C for a long time.
Why it matters
Rocket and jet engine “hot-section” parts (the components nearest the fire) face temperatures that would soften ordinary steels and many stainless alloys. They must also resist oxidation, thermal fatigue (cracking from repeated heating and cooling), and creep (slowly stretching under load and heat) over many cycles. Haynes 230 hits a sweet spot: excellent oxidation resistance, strong long-term stability, good weldability, and lower thermal expansion than most rival alloys, which reduces the thermal stress that cracks parts. Haynes states it can outlast stainless steels and some nickel alloys by as much as 100-to-1 at high temperature. The trade-off is that it gives up some peak short-term strength compared with precipitation-hardened superalloys like Inconel 718, and its high tungsten content makes it relatively dense and costly. That durability, plus good 3D-printing behavior, makes it attractive for modern, reusable rocket engines.
Where it is used
Its core commercial home is gas-turbine and jet-engine hot sections: combustion liners, transition ducts, flame holders, nozzle guide vanes, and thermocouple sheaths. In spaceflight, it appears in rocket combustion liners and high-temperature exhaust components, where hot, oxygen-rich combustion gases demand an oxidation- and fatigue-resistant metal.
It is also a demonstration material for 3D-printed, channel-cooled rocket nozzles. In these “regeneratively cooled” parts, coolant flows through tiny channels built into the wall to keep the metal below its limit while the engine fires. NASA and industry have demonstrated additively manufactured channel-wall nozzles using Haynes 230 alongside alloys such as Inconel 625, JBK-75, and NASA HR-1, built with techniques like directed-energy deposition and laser powder-bed fusion. (NASA’s channel-wall-nozzle work spans several alloys, so these demonstrations are best credited to that broader technology effort, with Haynes 230 as one of the proven materials.) The same heat-resistant properties also serve industrial furnace and chemical-process hardware operating above roughly 650 C.
Ni 57%, Cr 22%, W 14%, Mo 2%, Fe 3% max, Co 5% max
| DENSITY | 9 kg/m³ |
| TENSILE STRENGTH | 860 MPa |
| YIELD STRENGTH | 390 MPa |
| STRENGTH-TO-WEIGHT | 95875.1 kN·m/kg |
| MELTING POINT | 1,301 °C |
| MAX SERVICE TEMPERATURE | 1,149 °C |
| THERMAL CONDUCTIVITY | 8.9 W/m·K |
| THERMAL EXPANSION | 12.7 µm/m·K |
| CATEGORY | Superalloy |
| DESIGNATIONS | UNS N06230, AMS 5878 |
| MANUFACTURER | Haynes International |
| DENSITY | 9 kg/m³ |
| TENSILE STRENGTH | 860 MPa |
| YIELD STRENGTH | 390 MPa |
| MELTING POINT | 1,301 °C |
| MAX SERVICE TEMP | 1,149 °C |
| THERMAL CONDUCTIVITY | 8.9 W/m·K |
| THERMAL EXPANSION | 12.7 µm/m·K |
| CORROSION RESISTANCE | Excellent |
| WELDABILITY | Good |
| MACHINABILITY | Moderate |
| COST RATING | Very High |
