SMn420 steel

SMn420 steel
SMn420 is an alloy structural steel with a hardness ≤187HB. The executive standard is Japan JIS G4053-2003.
 
 
Product Introduction
Alloy structural steel: SMn420
Executive standard: Japan JIS G4053-2003
 
Characteristics and scope of application
SMn420 steel has medium strength, high plasticity during cold deformation, and good low temperature performance. Compared with carbon steel with corresponding carbon content, its hardenability is higher. Generally used as parts with smaller cross-sections, equivalent to 20Cr steel, can be used for carburizing pinions, small shafts, steel sleeves, piston pins, diesel engine sleeves, automobile steering roller shafts, valve jacks, etc.; can also be used for quenching and tempering For steel, such as cold heading bolts or large cross-section quenched and tempered parts.
 
 
Chemical composition

Standard	Grade	Chemical composition,%
		C	Si	Mn	S	P	Cr	Ni	Cu
JIS G4053	SMn420	0.17～0.23	0.15～0.35	1.20～1.50	≤0.030	≤0.030	≤0.35	≤0.25	≤0.30

 

 
Mechanical properties

Standard	Grade	Mechanical properties
		Tensile strength (MPa)	Yield strength (MPa)	Elongation  (%)	Reduction of area  (%)	Impact energy (J)	Impact toughness value (J/cm2)	Hardness
JIS G4053	SMn420	≥785(80)	≥590(60)	≥10	≥40	≥47	≥59(6)	≤187HB

 
 
 
● Heat treatment specification and metallographic structure:
Heat treatment specifications: 1) Quenching at 850℃, water cooling, oil cooling; tempering, 200℃, water cooling, air cooling. 2) Quenching at 880℃, water cooling, oil cooling, tempering, 200℃, water cooling, air cooling.
 
●Delivery status: delivery in the heat treatment (normalizing, annealing or high temperature tempering) or non-heat treatment status, the delivery status should be indicated in the contract.