Properties of Weldable Alloy Steel AISI 4320

Steel 4320 is a steel alloy that has casting, machining and welding capability. It is called a low alloy steel, with low carbon content. The carbon amount allows it to be forged, welded and machined. The manganese component allows for better machinability and better hardening properties. The 43xx steel alloys are used in pins, plates, valves and castings.

AISI 4320

Category	Steel
Class	Alloy steel
Type	Standard
Common Names	Nickel-chromium-molybdenum steel
Designations	United States: ASTM A322 , ASTM A331 , ASTM A505 , ASTM A519 , ASTM A535 , SAE J404 , SAE J412 , SAE J770 , UNS G43200

Composition Properties

The 4320 alloy steel contains the following alloy materials, including the weight percentage of the material:

Element	Weight %
C	0.17-0.22
Mn	0.45-0.65
P	0.035 (max)
S	0.04 (max)
Si	0.15-0.30
Cr	0.40-0.60
Ni	1.65-2.00
Mo	0.20-0.30

Mechanical Properties

At room temperature, with steel 4320 that was annealed at 850C, tensile strength is 579.2 MPa, which converts to 5906.2 kgf/cm^2. Yield strength, where permanent deformity occurs, is 609.5 MPa, which converts to 6215.17 kgf/cm2.

Properties		Conditions
		T (°C)	Treatment
Density (×1000 kg/m3)	7.7-8.03	25
Poisson's Ratio	0.27-0.30	25
Elastic Modulus (GPa)	190-210	25
Tensile Strength (Mpa)	579.2	25	annealed at 850°C
Yield Strength (Mpa)	609.5
Elongation (%)	29.0
Reduction in Area (%)	58.4
Hardness (HB)	163	25	annealed at 850°C
Impact Strength (J) (Izod)	109.8	25	annealed at 850°C

Testing at room temperature steel that has been annealed at 850C. Elongation of this steel is 29 percent. Reduction in area is 58.4 percent. Hardness of this steel using a Brinell hardness test is 163 HB.

Source: ehow.com, efunda