The grade 446 stainless steel is a ferritic, non-heat treatable
stainless steel that provides good resistance to high temperature
oxidation and corrosion. The following datasheet provides more
details of grade 446 stainless steel.
Chemical Composition of 446 Stainless Steel
The chemical composition of grade 446 stainless steel is outlined
in the following table.
| Element | Content (%) |
|---|
| Iron, Fe | 73 |
| Chromium, Cr | 23.0 - 27.0 |
| Manganese, Mn | 1.50 |
| Silicon, Si | 1.0 |
| Nickel, Ni | 0.25 |
| Carbon, C | 0.20 |
| Phosphorous, P | 0.040 |
| Sulfur, S | 0.030 |
Physical Properties of 446 Stainless Steel
The following table shows the physical properties of grade 446
stainless steel.
| Properties | Metric | Imperial |
|---|
| Density | 7.80 g/cm3 | 0.282 lb/in³ |
Mechanical Properties of 446 Stainless Steel
The mechanical properties of grade 446 stainless steel are
displayed in the following table.
| Properties | Metric | Imperial |
|---|
| Tensile strength | 550 MPa | 79800 psi |
| Yield strength (@strain 0.200%) | 345 MPa | 50000 psi |
| Elastic modulus | 200 GPa | 29000 ksi |
| Poisson's ratio | 0.27-0.30 | 0.27-0.30 |
| Elongation at break | 20% | 20% |
| Hardness, Brinell (estimated from Rockwell B) | 159 | 159 |
| Hardness, Knoop (estimated from Rockwell B) | 173 | 173 |
| Hardness, Rockwell A (estimated from Rockwell B) | 51.1 | 51.1 |
| Hardness, Rockwell B | 83 | 83 |
| Hardness, Vickers (estimated from Rockwell B) | 159 | 159 |
Thermal Properties of 446 Stainless Steel
The thermal properties of grade 446 stainless steel are given in
the following table.
| Properties | Metric | Imperial |
|---|
| Thermal expansion co-efficient (@0-100°C/32-212°F) | 10.4 µm/m°C | 5.78 µin/in°F |
| Thermal conductivity | 21.6 W/mK | 150 BTU in/hr.ft².°F |
Machinability of 446 Stainless Steel
Machinability of the grade 446 stainless steel is possible at slow
speeds with positive feeds, rigid mounts and sharp tooling
surfaces.
Welding of 446 Stainless Steel
The grade 446 stainless steel can be easily welded using most of
the traditional methods except oxyacetylene
welding. Type 308 welding material can be used if required, but it will
not exhibit scaling resistance equal to the base metal. Differences
in coefficient of thermal expansion of base and weld metal has to
be taken into consideration.
Forging of 446 Stainless Steel
Forging can be started at 1149°C (2100°F) and completed at 871°C
(1600°F). The last 10% of forging has to be performed below 871°C
(1600°F) to gain grain refinement and room temperature
embrittlement.
Hot Working of 446 Stainless Steel
The hot working of grade 446 stainless steel is performed in
between the ranges 1093- 1177°C (2000-2150° F). The last 10% of hot
working has to be performed below 871°C (1600°F) to gain grain
refinement
Cold Working of 446 Stainless Steel
The grade 446 stainless steel is more difficult to cold work than
other stainless steels due to the high level of chromium content.
Annealing of 446 Stainless Steel
Annealing of the grade 446 stainless steel has to be soaked at
816°C (1500°F) and then water quenched. The temperature should not
exceed 900°C (1650°F) at any time and slow cooling below 649°C
(1200°F) can cause loss of ductility.
Applications of 446 Stainless Steel
The grade 446 stainless steel can be used in the following
products:
- X-ray tube bases
- Boiler baffles
- Oil burner components
- Annealing boxes
- Industrial mufflers
- Kiln linings
- Glass molds
- Furnace parts
