Favorite  |  Set Home
SCM420 Forged Alloy Steel
 SCM420 alloy structure steel has high hardenability, no tempering brittleness, good weldability, little tendency to form cold crack, good machinability and cold strain plasticity. 

Corresponding to Domestic Grade Name: 20CrMo

Corresponding to Germany Grade Name: 25 crmo4 (1.7218)

Executive Standard: JIS G4053-2003

Features and Scope of Application:

SCM420 is generally used under the condition of quenching and tempering or carburizing. It is used to manufacture high-pressure pipes and various fasteners and advanced carburizing parts, such as gears and shafts, which work in non-corrosive media and medium with nitrogen and hydrogen mixture at working temperature below 250℃.

SCM420 Alloy Structural Steel

Chemical Composition (unit %) :

C: 0.18 ~ 0.23

Si: 0.15 ~ 0.35

Mn: 0.60 ~ 0.90

S: allowable residual content ≤0.030

P: allowable residual content ≤0.030

Cr: 0.90 ~ 1.20

Ni: allowable residual content ≤0.25

Cu: allowable residual content ≤0.30

Mo: 0.15 ~ 0.25

Mechanical Properties (Tempering and Tempering State) :

Tensile Strength σb (MPa) : ≥885(90)

Yield Strength σs (MPa) : ≥685(70)

Elongation Δ5 (%) : ≥12

Section Shrinkage ψ(%) : ≥50

Impact Work AKV (J) : ≥78

Impact Toughness Value α kV (J/ Cm&SUP 2;)A: 98 (10) or

Hardness: 197 hb or less

 

Heat Treatment Specification and Metallographic Structure:

Heat Treatment Specification: Quenching 880℃, water cooling, oil cooling;Tempering 500℃, water cooling, oil cooling.

Delivery Status: Delivered under heat treatment (normalizing, annealing or high temperature tempering) or without heat treatment. The delivery status shall be specified in the contract.