28Mn6 / 1.1170 Steel

28Mn6/1.1170 steel is Manganese steel for moderate and lower temperature use in pressure vessels.

Chemical Composition per EN 10083-2

 

GRADE	NUMBER	C	Si	Mn	P	S	Cr	Mo	Ni	Cr+Mo+Ni
28Mn6	1.1170	0.25-0.32	≤ 0.40	1.30-1.65	≤ 0.030	≤ 0.035	≤ 0.40	≤ 0.10	≤ 0.40	≤ 0.63

Applications

Used for weld fabrication of pressure vessels that require improved notch toughness for lower than ambient temperature service. Low and moderately stressed parts for vehicles, machines and engines.

Mechanical properties of   steel   28Mn6 (1.1170)

Nominal thickness (mm):	to 16	16 – 100	100 – 250	250 – 500	500 – 1000
Rm – Tensile strength (MPa) (+N)	630	600	570	540	540

Nominal thickness(mm):	to 16	16 – 100	100 – 250	250 – 500	500 – 1000
Re – Upper yield strength or Rp0.2 – 0.2% proof strength (MPa) (+N)	345	310	290	270	260

KV – Impact energy (J) (+QT)

+20° 40

Nominal thickness (mm):	to 16	16 – 100	100 – 250
A – Min. elongation Lo = 5,65 √ So (%) (+N)	17	18	18

Brinell hardness   (HBW):   (+S)	255
Brinell hardness   (HBW):   (+A)	223

Physical properties (average values) at ambient temperature

Modulus of elasticity [103 x N/mm2 ]: 210

Density [g/cm3 ]: 7.83

Soft Annealing

This will produce a maximum Brinell hardness of 223.

Normalizing

Normalizing temperature: 850-890 degree

Stress Relieving

Stress relieving to remove machining stresses should be carried out by heating to approx. 650o C, holding for 1-2 hours at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment.

Hardening

Harden from a temperature of 830-870 degree followed by water or oil quenching.

Tempering

Tempering temperature: 540-680 degree