SUS420F "tool-grade" martensitic steel, similar to early stainless steels like BHN high-chromium steel. Also used for surgical tools, it can be polished to a high luster. SUS420F (13Cr-0.3C-High S) is a steel grade that improves the machinability of SUS420J2 steel. SUS420F corresponds to China's GB Y3Cr13.

Chemical Composition

Carbon (C): 0.26~0.40

Silicon (Si): ≤1.00

Manganese (Mn): ≤1.25

Sulfur S: ≥0.15

Phosphorus (P): ≤0.060

Chromium (Cr): 12.00~14.00

Nickel (Ni): Allowable content ≤ 0.60

Molybdenum (Mo): Can be added up to ≤0.60

Tensile Strength σb (MPa): Quenched and tempered, ≥735

Condition yield strength σ0.2 (MPa): Quenched and tempered, ≥540

δ5 elongation (%): Quench and temper, ≥12

Section reduction rate ψ (%): Quenching and tempering, ≥40

Impact Energy Akv (J): Hardening and tempering, ≥24

Hardness: Annealed, ≤235HB; Quenched and Tempered, ≥217HB

Heat Treatment Specifications: 1) Annealing, cooled slowly at 800~900℃ or rapidly at about 750℃; 2) Quenching, oil-cooled at 920~980℃; 3) Tempering, rapidly cooled at 600~750℃.

Microstructure: Characterized by Martensitic morphology.

Generally delivered in heat treated condition; the type of heat treatment shall be specified in the contract; if not specified, the goods will be delivered in non-heat treated condition.