Stainless Steels
- CF8M
- CF8
- CF12M
- CF20
- CK20
- ASTM 743 series
- A351
- A74
PAK 450
Specially developed fully austenitic stainless steel. Producing excellent physical and mechancial properties.Totally non-magnetic, superior strength and corrosion resistance. Can be supplied as casting, forgings and as a rolled product.
PAK 450 was developed as the result of a request to produce an Austenitic cast Stainless Steel material with the same or similar corrosion and mechanical properties of wrought 316 types but, with a magnetic permeability values that were less than the standard for 300 series.
Usual values for these materials range from 1.02 to 1.08 and they are classed as 'nonmagnetic'.
The magnetic permeability of PAK 450 is 1.00, as tested on Dr. Fosters' Magnetic Permeameter, which shows the material to be magnetically inert.
The Alloy PAK 450 was invented by Keith Henley-Smith, who also holds the Patent on the material.
It is intended to be marketed by the Company 'Superstainless PL' and can be supplied in three forms; cast product, forged and rolled.
At the moment PAK 450 is manufactured by Graham Campbell Ferrum, under license to Superstainless PL as a cast product, it can also be supplied in the forged form and rolled product from offshore.
A series of NATA approved tests have been conducted on the material and a summary of the typical resulting data is as follows.
| Mechanical Properties of Cast material | |
| Proof stress | 250 MPa |
| Ultimate tensile strength | 550 MPa |
| Elongation | 51% |
| Magnetic permeability 1.00 | |
| Charpy impact tests - test piece 10x10mm. | |
| Ambient temp - 22C | 400 Joules |
| Temp - minus 40C | 255 Joules |
| Temp - minus 196C | 165 Joules |
| Hardness - 146 HBn | |
| Machinability - Good | |
| Mechanical properties of Forged Material | |
| Roof stress | 350 MPa |
| Ultimate tensile strength | 700 Mpa |
| Elongation | 55% |
| Magnetic permeability 1.00 | |
| Charpy impact tests - test piece 10x10mm. | |
| Test temp - minus 196C | |
| Longitudinal | 131 Joules |
| Transverse | 147 Joules |
| Hardness - 167 HBn | |
| Machinability - Good | |
| Mechanical properties of forged material solution annealed | |
| Roof stress | 401 MPa |
| Ultimate tensile strength | 724 Mpa |
| Elongation | 48% |
| Magnetic permeability 1.00 | |
| Charpy impact tests - test piece 10x10mm. | |
| Test temp - minus 196C | 178 Joules |
| Ambient temp | 233 Joules |
| Hardness - 186 HBn | |
| Machinabilty - Excellent | |
| Mechanical properties of Rolled Material | |
| *Product rolled from 25mm to 6mm | |
| Proof stress | 930MPa |
| Ultimate tensile strength | 980MPa |
| Elongation | 23% |
| Magnetic permeability 1.00 | |
| Charpy impact test test piece 5x10mm. | |
| Test temp - Ambient 21C | 38 Joules |
| Hardness - 340 HBn | |
| Machinability - Good | |
| Mechanical properties of Rolled material | |
| *Product rolled from 25mm to 3mm | |
| Proof stress | 1325MPa |
| Ultimate tensile strength | 1455MPa |
| Elongation | 4% |
| Magnetic permeability 1.00 | |
| Hardness - 380 HBn | |
| Machinability - Good | |
The corrosion resistant properties are superior to those of the 300 series of stainless steels as shown in standard pitting tests as carried out by NATA approved laboratories.
The material shows heat resistant stability to over 1000C
Keith Henley-Smith