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.
| 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 | |
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 Elasticity
193 kN/mm² | 27993 ksi
Modulus of Rigidity
73.6 kN/mm² | 10675 ksi
Heat Treatment of Finished Parts
| Condition as supplied by Alloy Wire | Type | Temperature | Time (Hr) | Cooling | |
| °C | °F | ||||
| 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 |