AISI 4330V

It is widely used in applications requiring exceptional strength-to-weight ratios and reliability under extreme stress, such as aerospace, oil and gas, and heavy machinery. The "V" designation indicates vanadium addition, which refines grain structure and improves mechanical properties.

Descriptions

1. Chemical Composition

AISI 4330V combines chromium, molybdenum, nickel, and vanadium for superior strength and toughness. Vanadium enhances grain refinement and resistance to creep and fatigue.

Element	Composition(% by Weight)	Role
Carbon (C)	0.28-0.33	Increases strength and hardness.
Manganese (Mn)	0.40-0.70	Improves hardenability and deoxidizes steel.
Silicon (Si)	0.15-0.35	Strengthens ferite and improves cleanliness.
Nickel (Ni)	1.65-2.00	Enhances core toughness and impact resistance.
Chromium (Cr)	0.70-0.90	Boosts hardenability and wear resistance.
Molybdenum (Mo)	0.20-0.30	Increases strength and creep resistance.
Vanadium (V)	0.05-0.10	Refines grain structure, improves fatigue strength.
Phosphorus (P)	0.025 max	Controlled impurity (minimizes brittleness).
Sulfur (S)	0.025 max	Controlled impurity (limits segregation).
Iron (Fe)	Balance	Base metal.

2. Mechanical Properties

AISI 4330V forgings achieve optimal performance through heat treatment (e.g., quenching and tempering). Properties vary based on processing methods.

Property	Normalized	Quenched &Tempered	As-Forged	Test Standard
Tensile Strength	760-930 MPa	930-1080 MPa	620-800 MPa	ASTM E8
Yield Strength(0.2%offset)	585-760 MPa	830-950 MPa	415-620MPa	ASTME8
Elongation (% in 50 mm)	18-22%	12-18%	15-20%	ASTME8
Reduction of Area	50-60%	45-55%	40-50%	ASTME8
Hardness (Brinell)	220-260HB	285-341HB	190-230HB	ASTME10
Impact Toughness(Charpy V)	50-80J(room temp)	40-60J	60-90J	ASTME23
Fracture Toughness(K<sub>IC</sub>)	120-150MPa√m	90-120 MPa/m	N/A	ASTME399