AISI 4130

AISI 4130 is a chromium-molybdenum (chromoly) low-alloy steel known for its high strength, toughness, and excellent weldability. It is widely used in applications requiring a balance of strength-to-weight ratio and resistance to fatigue.

Descriptions

1. Chemical Composition

AISI 4130 is alloyed with chromium and molybdenum to enhance hardenability, strength, and corrosion resistance. Its composition supports heat treatment for tailored mechanical properties.

Element	Composition (% by Weight)	Role
Carbon (C)	0.28-0.33	Increases strength and hardness.
Manganese (Mn)	0.40-0.60	Improves hardenability and deoxidization.
Silicon (Si)	0.15-0.35	Enhances strength and deoxidizes molten steel.
Chromium (Cr)	0.80-1.10	Boosts hardenability and corrosion resistance.
Molybdenum (Mo)	0.15-0.25	Improves high-temperature strength and creep resistance.
Phosphorus (P)	0.035 max	Residual element (impurity control).
Sulfur (S)	0.040 max	Residual element (impurity control).
Iron (Fe)	Balance	Base metal.

2. Mechanical Properties

AISI 4130 forgings achieve superior mechanical performance through heat treatment (e.g., quenching and tempering). Properties vary based on processing conditions.

Property	As-Forged	Normalized &Tempered	Quenched &Tempered	Test Standard
Tensile Strength	670-850 MPa	760-930 MPa	930-1080 MPa	ASTME8
Yield Strength (0.2% offset)	435-620 MPa	620-760 MPa	830-950MPa	ASTME8
Elongation (%in 50 mm)	15-20%	18-22%	12-18%	ASTME8
Reduction of Area	45-55%	50-60%	40-50%	ASTME8
Hardness (Brinell)	197-235 HB	220-260HB	285-341HB	ASTME10
Impact Toughness (Charpy V)	40-60J(room temp)	50-70J	30-50J	ASTME23