Alloy 20 CB 3 is an austenitic stainless steel with excellent resistance to hot sulphuric acid and many other aggressive environments that would readily attack stainless steel 316. This alloy exhibits superior resistance to stress-corrosion cracking in boiling 20 to 40% sulphuric acid.
Chemical Composition
| Element | Min % | Max % |
| C | – | 0.07 |
| Si | – | 1.00 |
| Mn | – | 2.00 |
| P | – | 0.045 |
| S | – | 0.035 |
| Cr | 19.00 | 21.00 |
| Mo | 2.00 | 3.00 |
| Ni | 32.50 | 38.00 |
| Cu | 3.00 | 4.00 |
| Nb | 8 x C | 1.00 |
| Fe | bal | |
| Specifications | Designations | Key Features | Typical Applications |
ISO 15156-3 | W.Nr 2.4660 | Excellent resistance to hot sulphuric acid & many other aggressive environments that would attack ST/ST 316 | Chemical and allied industries |
Density | 8.08 g/cm³ | 0.292 lb/in³ |
Melting Point | 1425°C | 2600°F |
Coefficient of Expansion | 14.69 μm/m °C (20 – 100°C) | 8.16 x 10-6 in/in °F (70 – 212°F) |
Modulus of Rigidity | 73.6 kN/mm² | 10675 ksi |
Modulus of Elasticity | 193 kN/mm² | 27993 ksi |
| Heat Treatment of Finished Parts | |||||
| Condition as supplied by Alloy Wire | Type | Temperature | Time (Hr) | Cooling | |
Time (Hr) | Cooling | ||||
Annealed or Spring Temper | Stress Relieve | 250 – 530 | 480 – 990 | 1 | Air |
| Properties | ||||
| Condition | Approx. tensile strength | Approx. operating temperature | ||
N/mm² | ksi | °C | °F | |
Annealed | 600 – 900 | 87 – 131 | -200 to +300 | -330 to +570 |
Spring Temper | 1200 – 1800 | 174 – 261 | -200 to +300 | -330 to +570 |
The above tensile strength ranges are typical. If you require different please ask.
