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, which forms 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
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Electrical Resistance
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0.60 x10 ^ -6 Ω .m
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Thermal conductivity
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13 W/m-K
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Maximum Temperature: Corrosion
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390℃
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Process Properties
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Machinability
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good
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Hot Forming
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good
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Hardness HB
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424
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Thermal Recovery
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Specific heat capacity
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480 J/kg-K
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Melting point
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1440℃
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Machinability
420 stainless steel offers very good machinability, the highest of commonly available stainless steels. It is best obtained in the subcritical annealed condition.
Weldability
420 (1.4021) round 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.
If the parts are to be used in the "welded" condition, a ductile joint can be obtained using a 309 stainless steel filler rod. AS 1554.6 presets 420 to be welded with Class 309 rods or electrodes.
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Dimensions mm |
| X20Cr13 |
6mm |
up to |
50mm |