Stainless Steel - Grade 420B / 1.4028

Description

Stainless Steel Grade 420A/1.4021 is a martensitic stainless steel with a high carbon content, providing high hardness and strength after heat treatment. Known for its excellent corrosion resistance, particularly in mild environments, 420A is commonly used in applications requiring high wear resistance and moderate corrosion resistance. The alloy is versatile, allowing for easy fabrication and is widely employed in industries such as cutlery, surgical instruments, and other tool manufacturing.

Chemical Composition

Element	Min	Max
Carbon (C)	0.26	0.35
Silicon (Si)	-	1.00
Phosphorus (P)	0.03 max
Manganese (Mn)	-	1.50
Silicon (Si)	0.5 max
Phosphorus (P)	-	0.040
Sulfur (S)	-	0.030
Chromium (Cr)	12.0	14.0

Mechanical Properties

Annealed Condition (+A):

Hardness: ≤245 HB

Tensile Strength (Rm): ≤800 MPa

Quenched & Tempered Condition (+QT850):

Yield Strength (Rp0.2): ≥650 MPa

Tensile Strength (Rm): 850-1000 MPa

Elongation (A): ≥10%

Impact Toughness (KV) at 20°C: ≥12J

Thermal & Physical Properties

Density: 7.73 g/cm³

Thermal Expansion Coefficient (20-100°C): 10.2 μm/m°C

Electrical Resistivity: 68 Microhm-cm

Modulus of Elasticity: 195 GPa

Thermal Conductivity (at 20°C): 27.4 W/m•K

Other Designations

DIN: 1.4028 (X30Cr13)

AISI: 420B

EN: X30Cr13

Fabrication and Heat Treatment

Annealing: Heat to 840-900°C, slow furnace cool to 600°C, then air cool

Hardening: Heat to 980-1035°C, oil quench

Tempering: 150-370°C, typically 625-675°C

Applications

420B / 1.4028 is commonly used for surgical and dental instruments, scissors, pump and valve parts due to its excellent hardness and corrosion resistance.

Supplied Forms

Bars (round, square, flat, hexagonal, customized)

Precision ground rods and bars

Features

High Hardness (up to 50 HRC)

Good Corrosion Resistance in mild environments

Magnetic in annealed and heat treated conditions

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