Bozhong 220: Medium hardness steel (440 HB) for blast protection

Bozhong  220 armour steel is dedicated to modern vehicles structures for protection against mines.

Bozhong  220 grade has the aimed mechanical properties hardness, thoughness, ductility for protection against mines explosions, while keeping an excellent workablilty, particulary bending and welding for realization of specific complex designs defined for blast protection.

Standard
Bozhong  220
Bozhong  220 satisfies requirements of following specifications:
• France : NF A 36-800 THD1
• Germany : TL 2350 Quality O
• U.K. : DEF STAN 95-24 Class 3A (420-480HB)
• USA : MIL 12560 Class 4a (420-460HB)

Chemical Analysis

	C	S	P	Si	Mn	Ni	Cr	Mo	B
4 to 50 mm (.16″ to 2″)	≤ .22	≤ .005	≤ .015	≤ .5	≤ 1.5	≤ 2.0	≤ 1	≤ .6	≤ 0.005
>50 to 80 mm (2″ to 3.15″)	≤ .24	≤ .005	≤ .015	≤ .5	≤ 1.5	≤ 5	≤ 1	≤ .6	≤ 0.005

Mechanical Properties

	As supplied	Hardness	Yield Strength		UTS		Elongation	Charpy V -40°Transversal to rolling direction
		HB	MPa	ksi	MPa	ksi	5d(%)	J	ft.lbs
4 to 50 mm (.16″ to 2″)	Required by spécifications	400 – 480	≥1100	≥ 160	≥ 1250	≥ 182	≥ 10	≥ 27	≥ 20
	Typical values	440	1150	165	1450	210	13	48	35
>50 to 80 mm (2″ to 3.15″)	Minimal Values	≥400	≥800	≥115	≥1300	≥188	≥9	≥20	≥15