Introduction
Stainless steel grade 445 is one of the most widely used precipitation hardening grade steels. Although this material is soft and ductile in the solution annealed condition, it is very capable of good properties with a single precipitation or aging treatment. This steel possesses good corrosion resistance, high harness, toughness and strength.
The following datasheet provides an overview of stainless steel grade 445.
AISI 445 stainless steel is a ferritic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 445 is the AISI designation for this material. S44500 is the UNS number.
It has a moderately high ductility among the wrought ferritic stainless steels in the database.
The graph bars on the material properties cards below compare AISI 445 stainless steel to: wrought ferritic stainless steels (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Chemical Composition of 445 Stainless Steel
The chemical composition of grade 445 stainless steel is outlined in the following table.
| Grade | C | Si | Mn | P | S | Cr | Ni | Fe |
| 445 | 0.02 | 1.00 | 1.00 | 0.04 | 0.012 | 19.0-21.0 | 0.60 | Bal |
Mechanical Properties of 445 Stainless Steel
The mechanical properties of grade 445 stainless steel are displayed in the following table.
| Properties | Metric | Imperial |
| Tensile strength | 427 MPa | 61931 psi |
| Yield strength | 205 MPa | 29732 psi |
| Modulus of elasticity | 190-210 GPa | 27557- 30457 ksi |
| Poisson’s ratio | 0.27-0.30 | 0.27-0.30 |
| Elongation at break | 22% | 22% |
| Hardness | 83 | 83 |
Manufacturing Process
The 445 stainless steel grade can be machined into long gummy chips. For heat treatment of this material, it must be soaked at 1038°C (1900°F) for 30 min and then cooled below 16°C (60°F) for complete martensite transformation. Common fusion and resistance methods can be used to weld grade 445 steel. Oxyacetylene welding should be avoided. AWS E/ER630 filler metal is recommended. The material has to be soaked for 1 h at 1177°C (2150°F) for performing forging. The material should not be worked below 1010°C (1850°F). Before final hardening, post-work solution treatment is required.
