A 540 Grade B21 Class 4 chemical information,mechanical properties, physical properties, mechanical properties, heat treatment, and Micro structure, etc. It also contains the use of A 540 Grade B21 Class 4

SAE A 540 Grade B21 Class 4

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This page is mainly introduced the A 540 Grade B21 Class 4 chemical information,mechanical properties, physical properties, mechanical properties, heat treatment, and Micro structure, etc. It also contains the use of A 540 Grade B21 Class 4,such as it is commonly used in bars, sheet,plates, steel coils, steel pipes,forged and other materials application.
Alloy-Steel Bolting Materials for Special Applications

Chemical composition(mass fraction)(wt.%)

Elements Min.(≥) Max.(≤) Similar Remarks
C   0.05
Si   0.20
Mn   0.50
P  
S  
Ni   remaining
Cr 15.00  17.00
Al 4.00  5.00
Cu  
Ti   0.50
Fe 2.00  4.00
N  
Mo   0.50
B   0.006
Zr   0.05

Mechanical Properties

Tensile strength 559~550 σb/MPa
Yield Strength 944 σ 0.2 ≥/MPa
Elongation 59 δ5≥(%)
ψ - ψ≥(%)
Akv - Akv≥/J
HBS 534~751 -
HRC 30 -

Physical Properties

Thermal expansion 68-45 e-6/K
Thermal conductivity 32-12 W/m.K
Specific heat 450-460 J/kg.K
Melting temperature 8774-0267 째C
Density 4202-7216 kg/m3
Resistivity 0.50-0.60 Ohm.mm2/m
     

Heat Treatment Regime

Annealing

Quenching

Tempering

Normalizing

Q & T

Size Availability

Steel Grade Specification Processing range(mm)
A 540 Grade B21 Class 4 Stainless Steels Round Bar and Hollow Bar Φ1 to Φ2000
Square and Flat Steel Φ10 to Φ100
Plate and Sheet 0.08-800(Thickness)*10-1500(Width)*Length
Tube or Pipe OD:Φ4-410; WT:1-35 mm; Lenght:10-12000
Coil and Strip Steel THK:0.1mm Width:1500mm
Forged Ring/Cylindrical/Disk

Technical specification/standard for download