AMS6416 300M/4340M alloy steel

300m steel is a kind of low alloy high strength steel, has become the world's highest strength, comprehensive performance is best, the most widely used one of the best gear steel and reputation.Its mechanical properties with high strength, high transverse plastic, high fracture toughness, fatigue performance and good corrosion resistance, etc.In China in the mid - 80 - s began AMS6417 copied by American aerospace material standard, and in 1990 by metallurgical and two joint technical appraisal of aeronautics and astronautics

AISI 4340 ultra high strength tensile steel round bar for aerospace application

Standards:ASTM,JIS,GB,EN(DIN,BS,NF) Or Per as clients’ requires.

Product Basic Information:

Size Range
Round Bar	Diameter(mm)	Length(mm)	--
Round Bar	30~1000	500~12000	--

Chemical Composition(%)
C	Mn	P	S	Si	Cr	Mo	Ni	V
0.38-0.46	0.60-0.90	0.010Max.	0.010max.	1.45-1.80	0.70-0.95	0.30-0.65	1.65-2.00	0.05min.

1.Chemical Composition and Mechanical Properties(In Quenched & Tempered State):

Material		4340M
Chemical Composition		Mechanical Properties(In Quenched & Tempered State)
C	0.38-0.46	Tensile strength(MPA)	1860
Si	0.17-0.37	Yield strength (MPA)	-
Mn	0.60-0.90	Elongation(δ5/%)	-
Cr	0.70-0.95	Reduction in Area (ψ/%)	25
Mo	0.30-0.65	Impact (J)	23
P	≤0.010	Hardness (Anealed Condition)	≤241HB
S	≤0.010
Cu	≤0.30
Ni	1.65-2.00
V	Min 0.05

2.Product Application Areas:

4340M steel USES vacuum arc melting technology to improve purity, plasticity, toughness, etc. AMS6416 standard USES non-vacuum smelting, which is the general aviation quality level. Other parts of the standard use vacuum smelting to achieve high quality aviation quality level.

By the standard heat treatment oil quenching and tempering, the tensile strength of the steel can reach more than 1860MPa, which is currently the highest strength of low-alloy ultra-high strength steel. High strength can reduce the weight of the parts, improving the strength has been one of the main goals of landing gear parts design. The main wing bearing components of the American aircraft are also 300M steel and used to the highest strength level.

3.Cherecteristics:

The fatigue resistance of 4340M steel is obviously better than that of 4340. This is extremely beneficial for the long life of the landing gear and other aircraft components and is the main reason why 300M steel is widely used in aircraft.

It contains 1.5% silicon, which improves the stress corrosion resistance of 300M steel.

4.Produce process:

EAF + LF + VD + Forged + Heat Treatment -Annealed