IS 4367:1991 40Ni6Cr4Mo3 Steel: Specifications & Listings
IS 4367:1991 40Ni6Cr4Mo3: 40Ni6Cr4Mo3 is a steel in IS 4367:1991 (Alloy Steel Forgings for General Industrial Use), which covers forgings in the as forged, heat-treated or machined condition.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Si
Mn
Ni
Cr
Mo
S
P
0.35-0.45
0.10-0.35
0.40-0.70
1.25-1.75
0.90-1.30
0.20-0.35
<=0.035
<=0.035
Mechanical Properties
Tensile Strength
900-1050 MPa
Yield Strength
700 MPa min
Elongation
>=15%
Izod Impact
55 J min
Hardness
266-311 HB
Hardness (soft annealed)
<=230 HB
Condition
Hardened and tempered, ruling section up to 150 mm
Typical Available Sizes
Round Bar
20-350 mm dia
Flat Bar
25-200 mm width
Sizes are indicative. Contact seller for exact availability.
More data from IS 4367:1991
From the standard
Properties by ruling section4 sections
Tensile strength (MPa)
Yield strength, min (MPa)
Elongation, min (%)
Izod impact, min (J)
Hardness (HB)
Limiting ruling section (mm)
900 to 1050
700
15
55
266 to 311
150
1000 to 1150
800
13
48
295 to 341
100
1100 to 1250
880
11
41
325 to 370
63
1200 to 1350
1000
10
30
355 to 399
30
Test condition: hardened and tempered. Maximum hardness in the soft annealed condition: 230 HB.
Source: IS 4367:1991 with Amendments 1 and 2, Table 3
Sulphur, phosphorus and aluminium limitsordering options
Option 1
Sulphur and phosphorus 0.030 max each
Option 2
Sulphur 0.020 to 0.035, phosphorus 0.035 max
Aluminium, when the steel is aluminium killed
0.02 to 0.05
The purchaser orders sulphur and phosphorus under option 1 or option 2.
Source: IS 4367:1991 with Amendments 1 and 2, Table 1, notes 1 and 2