This group of alloys are used for their outstanding corrosion and high temperature resistance. Many are metallurgically related to the austenitic stainless steels but are much more highly alloyed, particularly with nickel, chromium and molybdenum in order to enhance their corrosion resistance. These alloys are used resist extremely corrosive conditions in the energy, power, chemical and petrochemical industries.
The term "superalloy" is applied to alloys which have outstanding high temperature strength and oxidation resistance. The nickel-based superalloys contain carefully balanced alloying additions of chromium, cobalt, aluminium, titanium and other elements. Often components are produced by carefully controlled solidification in order to get an optimum directionally solidified or even single crystal structure. These components can have strengths at 1000°C which exceed that of ordinary steels at room temperature. They are essential in the hottest parts of gas turbines both for power generation and aircraft.
Nickel and nickel alloys are used for a wide variety of applications, the majority of which involve corrosion resistance and/or heat resistance. Some of these include:
| Type | Ni | C | Mn | Fe | S | Si | Cu | Cr | Al | Ti | Mg | Cb | Mo | Others | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 200 | 99.5 | .080 | .180 | .20 | .005 | .180 | .130 | - | - | - | - | - | - | - | |||
| 201 | 99.5 | .010 | .180 | .20 | .005 | .130 | .130 | - | - | - | .050 | - | - | - | |||
| 205 | 99.5 | .080 | .180 | .10 | .004 | .080 | .080 | - | - | .030 | - | - | - | - | |||
| 211 | 95.0 | .100 | 4.75 | .380 | .008 | .080 | .130 | - | - | - | - | - | - | - | |||
| 212 | 97.0 | .200 | 2.00 | .750 | .015 | .150 | .20 | - | - | - | - | - | - | - | |||
| 220 | 99.5 | .040 | .100 | .050 | .004 | .030 | .050 | - | - | .030 | .050 | - | - | - | |||
| 230 | 99.5 | .050 | .080 | .050 | .004 | .020 | .050 | - | - | .003 | .060 | - | - | - | |||
| Monel (Nickel-Copper) Alloys. | 400 | 66.5 | 0.15 | 1.00 1.25 0.012 0.25 | 31.5 | ||||||||||||
| Incoloy (Nickel-Chromium) Alloys | |||||||||||||||||
| 600 | 76.0 | 0.08 | 0.5 | 8 | 0.008 | 0.25 | 0.25 | 15.5 | - | - | - | - | - | - | |||
| 601 | 60.5 | 0.05 | 0.5 | 14.1 | 0.007 | 0.25 | 0.5 | 23 | 1.35 | - | - | - | - | - | |||
| 625 | 61.0 | 0.05 | 0.25 | 2.5 | 0.008 | 0.25 | - | 21.5 | 0.2 | 0.2 | - | Ta | 9 | - | |||
| X-750 | 73.0 | 0.04 | 0.5 | 7 | 0.005 | 0.25 | 0.25 | 15.5 | 0.7 | 2.5 | - | 3.65 | - | - | |||
| 751 | 72.5 | 0.05 | 0.5 | 7 | 0.005 | 0.25 | 0.25 | 15.5 | 1.2 | 2.3 | - | Ta | - | - | |||
| 0.95 | |||||||||||||||||
| Ta 0.95 | |||||||||||||||||
| Incoloy (Nickel-Iron-Chromium) Alloys | |||||||||||||||||
| 800 | 32.5 | 0.05 | 0.75 | 46 | 0.008 | 0.5 | 0.38 | 21 | 0.38 | 0.38 | - | - | - | - | |||
| 801 | 32.0 | 0.05 | 0.75 | 44.5 | 0.008 | 0.5 | 0.25 | 20.5 | - | 1.13 | - | - | - | - | |||
| 802 | 32.5 | 0.35 | 0.75 | 46 | 0.008 | 0.38 | - | 21 | 0.58 | 0.75 | - | - | - | - | |||
| 804 | 41.0 | 0.05 | 0.75 | 25.4 | 0.008 | 0.38 | 0.38 | 29.5 | 0.3 | 0.6 | - | - | - | - | |||
| 805 | 36.0 | 0.12 | 0.75 | Sal. | 0.02 | 0.5 | 0.5 | 7.5 | - | - | - | - | 0.50 | - | |||
Titanium alloys are metals which contain a mixture of titanium and other chemical elements. Such alloys have very high tensile strength and toughness (even at extreme temperatures). They are light in weight, have extraordinary corrosion resistance and the ability to withstand extreme temperatures. However, the high cost of both raw materials and processing limit their use to military applications, aircraft, spacecraft, medical devices, connecting rods on expensive sports cars and some premium sports equipment andconsumer electronics
Although "commercially pure" titanium has acceptable mechanical properties and has been used for orthopedic and dental implants, for most applications titanium is alloyed with small amounts of aluminum and vanadium, typically 6% and 4% respectively, by weight. This mixture has a solid solubility which varies dramatically with temperature, allowing it to undergo precipitation strengthening. This heat treatment process is carried out after the alloy has been worked into its final shape but before it is put to use, allowing much easier fabrication of a high-strength product.
| Trade Name | UNS | Titanium Industry Specifications | Chemical Composition | Min. Tensile (KSI) | Min. Yield (KSI) | Hardness | Modulus of Elasticity | Poisson's Ratio |
|---|---|---|---|---|---|---|---|---|
| Grade 1 | UNS R50250 |
AMS AMS-T-81915, ASTM F67(1), B265(1), B338(1), B348(1), B381(F-1), B861(1), B862(1), B863(1), F467(1), F468(1), F1341, MIL SPEC MIL-T-81556 |
C 0.10 max, Fe 0.20 max, H 0.015 max, N 0.03 max, O 0.18 max, Ti Remaining |
35 | 25 | 14.9 | 103 GPa | 0.34-0.40 |
| Grade 2 | UNS R50400 |
AMS 4902, 4941, 4942, AMS-T-9046, ASTM F67(2), B265(2), B337(2), B338(2), B348(2), B367(C-2), B381(F-2), B861(2), B862(2), B863(2), F467(2), F468(2), F1341, MIL SPEC MIL-T-81556, SAE J467(A40) |
C 0.10 max, Fe 0.30 max, H 0.015 max, N 0.03 max, O 0.25 max, Ti Remaining |
50 | 40 | 14.9 | 103 GPa | 0.34-0.10 |
| Grade 5 | UNS R56400 |
AMS 4905, 4911, 4920, 4928, 4930, 4931, 4932, 4934, 4935, 4954, 4963, 4965, 4967, 4993, AMS-T-9046, AMS-T-81915, AS7460, AS7461, ASTM B265(5), B348(5), B367(C-5), B381(F-5), B861(5), B862(5), B863(5), F1472, AWS A5.16 (ERTi-5), MIL SPEC MIL-T-81556 |
AI 5.5-6.75 max, C 0.10 max, Fe 0.40 max, H 0.015 max, N 0.05 max, O 0.20 max, Ti Remaining, V 3.5-4.5 |
130 | 120 | 16.4 | 114 GPa | 0.30-0.33 |
| Grade 7 | UNS R52400 | ASTM B265(7), B338(7), B348(F-7), B861(7), B862(7), B863(7), F467(7), F468(7) |
C 0.10 max, Fe 0.30 max, H 0.015 max, N 0.03 max, O 0.25 max, Ti Remaining, Other Pd 0.12-0.25 |
50 | 40 | 14.9 | 103 GPa | - |
| Grade 9 | UNS R56320 | AMS 4943, 4944, 4945, AMS-T-9046, ASME SFA5.16(ERTi-9), ASTM B265(9), B338(9), B348(9), B381(9), B861(9), B862(9), B863(9), AWS A5.16(ERTi-9) |
AI 2.5-3.5, C 0.05 max, Fe 0.25 max, H 0.013 max, N 0.02 max, O 0.12 max, Ti Remaining, V 2.0-3.0 |
90 | 70 | 13.1 | 107 GPa | 0.34 |
| Grade 12 | UNS R53400 | ASTM B265(12), B338(12), B348(12), B381(F-12), B861(12), B862(12), B863(12) |
C 0.08 max, Fe 0.30 max, H 0.015 max, Mo 0.2-0.4, N 0.03 max, Ni 0.6-0.9, O 0.25 max, Ti Remaining |
70 | 50 | 14.9 | 103 GPa | - |