420MOD High Nitrogen Martensitic Stainless Steel Hardness up to HRC59

420MOD is a high nitrogen martensitic stainless steel that combines the hardness of 440C with the corrosion resistance of 630 stainless steel(17-4PH), while also having much better toughness than commen martensitic stainless steel.
Nitrogen element has been added into 420MOD in order to enhance the hardness and corrosion resistance of the material. 420MOD is especially suitable for operating environments that require both wear resistance and corrosion resistance.
The biocompatibility test of 420MOD was carried out by the laboratory of Soochow University, and all test data met medical requirements, including acute toxicity test, pyrogen test, in vitro cytotoxicity test, skin sensitization test, and intradermal reaction test.

Nominal chemical composition(%, wt)

C: 0.42
Cr: 16.00
Mo: 1.80
V: 0.35
N: 0.20

Main characters

• Consumable electrode remelted martensitic stainless steel combining remarkable corrosion resistance with a very high level of hardness(>440C ).
• The well-balanced composition provides a structure free from coarse carbides resulting in excellent fatigue resistance.
• Excellent contact fatigue resistance.
• Good high-temperature resistance.
• Excellent polishability.

Applications

• Bearings, bearing components, ball-screws.
• Spherical bearings.
• Valve seats.
• Guide collars.
• Spindles.
• Extruder core shafts
• Plastic& glass molds

Heat treatment

Oil or gas quench from 1050°C. Sub zero treatment (-70/-80°C). Temper at 180°C:
- HRC: 59
This is the recommended treatment cycle for maximum hardness and very good corrosion resistance.

Oil or gas quench from 1075°C. Sub-zero treatment (-70/-80°C). Double temper at 500°C.
- HRC: 59
This treatment is recommended for hot work applications, with a high level of hardness and moderate corrosion resistance.

Oil or gas quench from 1050°C. Double temper at 650°C.
- UTS: 1200 N/mm2
- 0.2 % Yield strength: 900 N/mm2
This treatment is recommended where induction hardening of the surface is to be undertaken. The tempering temperature can be adjusted according to the core strength required.