1. Introduction
420F stainless steel
name: martensitic stainless steel
420F characteristics and applications:
420F stainless steel is a steel grade that improves the cutting performance of 420J2 steel.
420F chemical composition:
C: 0.30~0.40
Mn:≤1.25
Si:≤1.00
Cr: 12.0~14.0
Ni: ≤0.50
P: ≤0.06
S:≥0.15
Mo:≤0.06
Note: ①Single values are the highest values unless otherwise specified; ②When used in certain pipe making processes, the nickel content of some types of austenitic stainless steels must be slightly higher than the values shown in the table; ③optional; ④The highest Ta content is 0.10%; ⑤The highest content is 0.75%; ⑥The highest content is 0.70%
2. Mechanical properties
Tensile strength σb (MPa): quenched and tempered, ≥735
Conditional yield strength σ0.2 (MPa): quenched and tempered, ≥530
Elongation δ5 (%): quenching and tempering, ≥12
Reduction of area ψ (%): quenching and tempering, ≥40
Impact energy Akv (J): quenching and tempering, ≥24
Hardness: annealing, ≤235HB; quenching and tempering, ≥217HB
3. Heat treatment specifications and metallographic
Heat treatment specifications: 1) Annealing, 800～900℃ slow cooling or about 750℃ fast cooling; 2) Quenching, 920～980℃ oil cooling; 3) Tempering, 600～750℃ fast cooling.
Metallographic structure: The structure is characterized by martensite.
4. Delivery status:
Generally , delivery is in the heat treatment state, and the type of heat treatment is indicated in the contract; if it is not indicated, the delivery is in the non-heat treatment state.