SCM420 alloy structure steel has high hardenability, no tempering brittleness, good weldability, little tendency to form cold[SCALE STEEL] crack, good machinability and cold strain plasticity.
Corresponding to Domestic Grade Name: 20CrMo
Corresponding to Germany Grade Name: 25 crmo4 (1.7218)
Executive Standard:[SCALE STEEL] 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 [SCALE STEEL]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 [SCALE STEEL]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 [SCALE STEEL]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.