A martensitic machining bar with machinability enhanced through the addition of Sulphur.
As for most other free-machining stainless steels the improvement in machinability is achieved by addition of sulphur which forms manganese sulphide inclusions; this sulphur addition also lowers the corrosion resistance, weldability and formability to below that of its non-free machining equivalent Grade 410.
Martensitic stainless steels are optimised for high hardness, and other properties are to some degree compromised. Fabrication must be by methods that allow for poor weldability and usually also allow for a final harden and temper heat treatment. Corrosion resistance is lower than the common austenitic grades, and their useful operating temperature range is limited by their loss of ductility at sub-zero temperatures and loss of strength by over-tempering at elevated temperatures.
Chemical Composition
Spec: EN 10088-3:2005 1.4021 Steel
| Chemical Element | % Present |
Carbon (C) | 0.16 - 0.25 |
Chromium (Cr) | 12.00 - 14.00 |
Manganese (Mn) | 1.50 max |
Silicon (Si) | 1.00 max |
Phosphorous (P) | 0.04 max |
Sulphur (S) | 0.03 max |
Iron (Fe) | Balance |
| Physical Property | Value |
Density | 7.75 g/cm³ |
Thermal Expansion | 10.3 x10^-6 /K |
Modulus of Elasticity | 200 GPa |
Thermal Conductivity | 24.9 W/m.K |
Electrical Resistivity | 0.055 x10^-6 Ω .m |
Spec: EN 10088-3:2005
Bar - Up to 160mm Dia / Thickness
| Mechanical Property | Value |
Proof Stress | 500 - 600 MPa |
Tensile Strength | 700 - 950 MPa |
Elongation A | 12 - 13 % |
Alloy Designations
1.4021 is similar, but may not be a direct equivalent to:
420
UNS42000
1.4021, 1.4024, 1.4028, 1.4029, 1.4030, 1.4034
Supplied Forms
Bar
Applications
Typical applications include:
Valve Parts
Pump Shafts
Automatic Screw Machined Parts
Motor Shafts
Washing Machine Components
Bolts and Nuts
Studs
Gears
Shear Blades
Cutlery (Blades)
Surgical Instruments
