Overview
Monel is a solid-solution binary alloy. As nickel and copper are mutually soluble in all proportions, it is a single-phase alloy. Compared to steel, Monel is very difficult to machine as it work-hardens very quickly. It needs to be turned and worked at slow speeds and low feed rates. It is resistant to corrosion and acids, and some alloys can withstand a fire in pure oxygen. It is commonly used in applications with highly corrosive conditions. Small additions of aluminium and titanium form an alloy (K-500) with the same corrosion resistance but with much greater strength due to gamma prime formation on aging.
Monel is typically much more expensive than stainless steel. Monel alloy 400 has a specific gravity of 8.80, a melting range of 1300–1350 °C, an electrical conductivity of approximately 34% IACS, and (in the annealed state) a hardness of 65 Rockwell B. Monel alloy 400 is notable for its toughness, which is maintained over a considerable range of temperatures. Monel alloy 400 has excellent mechanical properties at subzero temperatures. Strength and hardness increase with only slight impairment of ductility or impact resistance.
The alloy does not undergo a ductile-to-brittle transition even when cooled to the temperature of liquid hydrogen. This is in marked contrast to many ferrous materials which are brittle at low temperatures despite their increased strength.
Specification
ASTM B564-19 Standard Specification for Nickel Alloy Forgings.
| Specifications | ASTM B564 / ASME SB564 |
| Size | 1/2″NB TO 48″NB |
| Standards | ANSI/ASME B16.5, B 16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, etc. |
| Class / Pressure | 150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc. |
| Standard | ANSI Flanges, ASME Flanges, BS Flanges, DIN Flanges, EN Flanges, etc. |
Pipe Smls | Pipe Welded | Tube Smls | Sheet / Plate | Bar | Forging | Fitting |
B165 | B725 | B163 | B127 | B164 | B564 | B366 |
Chemical Requirements
| Grade | Ni | C | Mn | S | Si | Cu | Fe | Al |
| Monel 400 | 63.0 min | 0.3 max | 2.0 max | 0.02 max | 0.5 max | 28.0 - 34.0 | 1.0 - 2.5 | 0.50 max |
Mechanical Properties
Product Form | Condition | Tensile (ksi) | .2% Yield (ksi) | Elongation (%) | Hardness (HRB) |
Rod & Bar | Annealed | 75-90 | 25-50 | 60-35 | 60-80 |
Rod & Bar | Cold-Drawn Stress Relieved | 84-120 | 55-100 | 40-22 | 85-20 HRC |
Plate | Annealed | 70-85 | 28-50 | 50-35 | 60-76 |
Sheet | Annealed | 70-85 | 30-45 | 45-35 | 65-80 |
Tube & Pipe Seamless | Annealed | 70-85 | 25-45 | 50-35 | 75 max* |
Applications
- 1. Chemicals
- 2. Petrochemicals
- 3. Oil & Natural Gas Organization
- 4. Fats, Fertilizers
- 5. Sugar Mills & Distilleries
- 6. Cement Industries
- 7. Ship Builders
- 8. Paper Industries
- 9. Pumps, Automation, Paints
- 10. Steel Industries
