AISI 8630

It is widely used in heavy-duty applications requiring a balance of strength, ductility, and wear resistance, particularly after heat treatment. AISI 8630 forgings are ideal for components exposed to high stress, shock loads, and cyclic environments.

Descriptions

1. Chemical Composition

AISI 8630 contains nickel, chromium, and molybdenum to enhance core toughness and hardenability, while its moderate carbon content supports heat treatment.

Element	Composition(% by Weight)	Role
Carbon (C)	0.28-0.33	Provides base strength and hardness.
Manganese (Mn)	0.70-0.90	Improves hardenability and deoxidizes steel.
Silicon (Si)	0.15-0.35	Strengthens ferrite and improves cleanliness.
Silicon (Si)	0.40-0.70	Enhances core toughness and impact resistance.
Chromium (Cr)	0.40-0.60	Boosts hardenability and wear resistance.
Molybdenum (Mo)	0.15-0.25	Improves strength and creep resistance.
Phosphorus (P)	0.035 max	Controlled impurity (minimizes brittleness).
Sulfur (S)	0.040 max	Controlled impurity (improves machinability).
Iron (Fe)	Balance	Base metal.

2. Mechanical Properties

AISI 8630 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	620-795MPa	900-1080 MPa	550-700MPa	ASTM E8
Yield Strength (0.2% offset)	415-585MPa	750-950MPa	350-500MPa	ASTME8
Elongation (% in 50mm)	18-22%	12-18%	15-20%	ASTME8
Reduction of Area	50-60%	45-55%	40-50%	ASTM E8
Hardness (Brinell)	197-235HB	285-341HB	170-210HB	ASTME10
Impact Toughness(Charpy V)	50-80J(room temp)	40-60J	60-90J	ASTM E23
Fracture Toughness(K<sub>IC</sub>)	110-140MPaVm	90-120 MPa√m	N/A	ASTME399