Introduce

420J2 is inexpensive and highly corrosion resistant steel. It has good corrosion resistance in mild atmosphere

Applications

Stainless steel grade 420J2 is used in the following application areas:
Surgical instruments
Daggers and swords
Budget knives and diving knives
Haircutting scissors and domestic scissors

Standard

JIS G4305 Cold Rolled Stainless Steel Strip and Sheet

Chemical component

Mechanical Property Annealed

QT Heat-treatment

cold-rolled steel Sheet thickness:1.5mm
Quenching condition: Air cooling after holding for 15 minutes at 1040ºC
As-quenched hardness (HRC)=57
Holding time for tempering:2 hours

Stainless steel grade 420J2 is machinable both in hardened and tempered conditions such as turning, drilling, and bending; however it is recommended that machining in hardened condition should be avoided as far as possible.

Welding

Welding of stainless steel grade 420J2 is easy. It is recommended that welding in annealed or hardened and tempered conditions should be avoided as it causes formation of brittleness, resulting in cold cracking due to contraction stresses.
Pre-heating and inter-pass temperature control during welding, followed by very slow cooling and post-weld annealing are good measures to take to prevent cracking.

Annealing

Annealing of this material can be performed by heating uniformly to 840-900°C (1544-1652°F) and held until the temperature is uniform throughout the section. Soaking and cooling is required.

Heat Treatment

Stainless steel grade 420J2 has to be heated uniformly to 730-790°C (1346-1454°F) and held until temperature is uniform throughout the section.

Hardening

Stainless steel grade 420J2 can be hardened by heating 950-1020°C (1742-1868°F) and held until temperature is uniform throughout the section. This should be followed by quenching in oil or air cooling. Tempering should be done when it is slightly warm.