Nov 26 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesThermal PropertiesOther DesignationsFabrication and Heat Treatment Machinability Forming Welding Heat Treatment Forging Hot Working Cold Working Annealing Aging HardeningApplications
Introduction
Super alloys or high performance alloys have good creep and oxidation resistance. They can be used at very high temperatures, can withstand extreme mechanical stress, and also used where high surface stability is required. They can be produced in a variety of shapes. There are three groups of alloys such as nickel-based, iron-based and cobalt-based alloys. Cobalt-based super alloys have higher melting points than nickel-based or iron-based alloys.
Hastelloy(r) C-4 is a wrought nickel-chromium-molybdenum alloy. It has high corrosion resistance. The following datasheet gives an overview of Hastelloy(r) C-4.
Chemical Composition
The chemical composition of Hastelloy(r) C-4 is outlined in the following table.
| Element |
Content (%) |
| Chromium, Cr |
14-18 |
| Molybdenum, Mo |
14-17 |
| Iron, Fe |
3 max |
| Cobalt, Co |
2 max |
| Manganese, Mn |
1 max |
| Titanium, Ti |
0.7 max |
| Silicon, Si |
0.08 max |
| Phosphorus, P |
0.04 max |
| Sulfur, S |
0.03 max |
| Carbon, C |
0.015 max |
| Nickel, Ni |
Remainder |
Physical Properties
The following table shows the physical properties of Hastelloy(r) C-4.
| Properties |
Metric |
Imperial |
| Density |
8.64 g/cm³ |
0.312 lb/in³ |
| Melting point |
1427°C |
2600°F |
Mechanical Properties
The mechanical properties of Hastelloy(r) C-4 are outlined in the following table.
| Properties |
Metric |
Imperial |
| Tensile strength |
738 MPa |
107000 psi |
| Yield strength ( @ 0.2% offset) |
492 MPa |
71400 psi |
| Elastic modulus |
211 GPa |
30600 ksi |
| Elongation at break (in 50.8 mm) |
42% |
42% |
Thermal Properties
The thermal properties of Hastelloy(r) C-4 are displayed in the following table.
| Properties |
Metric |
Imperial |
| Thermal expansion co-efficient (@ 20°C/68°F) |
10.8 µm/m°C |
6 µin/in°F |
| Thermal conductivity (@ 23°C/73°F) |
10.1 W/mK |
70.1 BTU in/hr.ft².°F |
Other Designations
Other designations that are equivalent to Hastelloy(r) C-4 include:
- ASTM B574
- ASTM B575
- ASTM B619
- ASTM B622
- ASTM B626
- DIN 2.4610
Fabrication and Heat Treatment
Machinability
Hastelloy(r) C-4 can be machined using conventional methods.
Forming
Hastelloy(r) C-4 can be easily formed using conventional techniques.
Welding
Except submerged arc and oxy-acetylene welding methods, Hastelloy (r ) C-4 can be welded using all other welding methods.
Heat Treatment
Hastelloy(r) C-4 is heat treated by annealing at 1066°C (1950°F) followed by quenching.
Forging
Hastelloy(r) C-4 is hot forged at 955 to 1177°C (1750 to 2150°F).
Hot Working
Hastelloy(r) C-4 is hot extruded or hot worked similar to that of stainless steels.
Cold Working
Hastelloy(r) C-4 can be cold worked using conventional methods.
Annealing
Hastelloy(r) C-4 is annealed at 1066°C (1950°F) followed by quenching.
Aging
Hastelloy(r) C-4 is aged at 649°C (1200°F) for 10 h in order to improve its yield strength and ductility without decreasing its ultimate tensile strength.
Hardening
Hastelloy(r) C-4 is hardened by cold working.
Applications
Hastelloy(r) C-4 is used for manufacturing chemical process equipments.