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.
