1.4021

Martensitic processing bar with improved workability with the addition of sulfur .

As with many other free-work stainless steels, improvement in machinability is achieved by the addition of sulfur forming manganese sulfur inclusions ; This sulfur addition also reduces corrosion resistance, weldability, and formability below the non-free machining equivalent 410 (1.4021) round stainless steel grade .

Martensitic stainless steels are optimized for high hardness and other properties are somewhat at risk. Fabrication should be done by methods that allow poor weldability and generally allow a final hardening and tempering heat treatment. Corrosion resistance is inferior to common austenitic grades, and the useful operating temperature range is limited by loss of ductility at sub-zero temperatures and power loss due to excessive tempering at high temperatures .

UNS42000

Electrical Properties

Process Features

Thermal Recovery

Machinability

420 stainless steels offer very good machinability , the highest of commonly available stainless steels . It is best obtained in the subcritical annealed state.

Weldability

420 (1.4021 ) square stainless steel has poor weldability .

Preheat to 150-320 ° C and postheat at 610-760 ° C. Class 420 coated welding rods are recommended for high strength joints where post-weld hardening and tempering heat treatment will be performed.