IS 11169 (Part 1):2022 31Cr2Mo1BT Steel: Specifications & Listings
IS 11169 (Part 1):2022 31Cr2Mo1BT: Cold heading quality boron alloyed steel 31Cr2Mo1BT to IS 11169 (Part 1):2022 for quenching and tempering after cold heading or cold extrusion, supplied as wire rod, bars or wire of 2 to 100 mm. Maximum tensile strength annealed is 570 MPa. It can be ordered with hardenability requirements (H, CH).
Cold heading and cold extrusion of parts that are quenched and tempered; the standard covers bars, wire rods and wires of 2 to 100 mm (clause 1.1, Annex C)
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
B
C
Cr
Cu
Mn
Mo
P
S
Si
0.0008-0.005
0.28-0.33
0.40-0.55
<=0.25
0.90-1.20
0.10-0.15
<=0.025
<=0.025
<=0.30
Mechanical Properties
Core Hardness (CH)
>=45 HRC up to 30 mm
Tensile Strength, annealed (+AC)
<=570 MPa (over 5 to 40 mm)
More data from IS 11169 (Part 1):2022
From the standard
Other composition limitsfrom the table notes and clauses
Values
Maximum unless a range is given (ladle analysis)
Silicon
Lower silicon contents may be agreed when ordering, with due regard to the effect on properties such as hardenability
Aluminium
0.020 to 0.050 percent may be added to improve cold heading
Ordered with hardenability
Small deviations from these limits are allowed (not for sulphur and phosphorus): up to 0.01 percent for carbon and the Table 1 values for other elements
Deoxidation
Aluminium killed (clause 6.2)
Elements not listed are not added intentionally without the purchaser's agreement, except those used to finish the heat.
Source: IS 11169 (Part 1):2022, Table C.3 and its notes, clause 6.2
Tensile strength and reduction of area by delivery conditionby delivery condition and size
Delivery condition
Diameter (mm)
Tensile strength, max (MPa)
Reduction of area, min (%)
+AC or +AC+PE
over 5 to 40
570
61
+AR+C+AC
2 (incl.) to 5
570
63
+AR+C+AC
over 5 to 40
550
63
+AR+C+AC+LC
2 (incl.) to 5
610
61
+AR+C+AC+LC
over 5 to 40
590
61
+AC+C
over 5 to 40
690
56
Codes: +AR as hot rolled, +PE peeled, +C cold drawn, +AC annealed to spheroidized carbides, +LC skin passed. For non-circular sections the properties are agreed between manufacturer and purchaser. In the +AR condition the tensile values do not suit the whole composition range; take care that they match the hardenability needs. Table C.7 heads the last reduction of area column as maximum; shown here as minimum.
Source: IS 11169 (Part 1):2022, Table C.7
Hardenability, end quench test (H)Hardness band
Hardness band (HRC, minimum to maximum) by distance from the quenched end (mm)
1.5
3
5
7
9
11
13
15
20
25
30
35
40
45
50
Distance from quenched end (mm)
1.5
3
5
7
9
11
13
15
20
25
30
35
40
45
50
Maximum, HRC
54
54
54
53
53
52
51
51
48
43
41
-
-
-
-
Minimum, HRC
48
48
47
47
45
45
41
39
31
27
25
-
-
-
-
Applies when ordered with the symbol H; otherwise for guidance only. Jominy test as per IS 3848, austenitizing at 860 ± 5 °C.
Source: IS 11169 (Part 1):2022, Table C.10
Core hardening (CH)CH ordering
Austenitizing temperature
860 °C ± 5
Minimum core hardness, 90 percent martensite
45 HRC
Maximum diameter for 90 percent martensite in the core
30 mm
Applies when ordered with the symbol CH. The diameter is the one reached with the lowest hardenability of the grade; HH grades allow a larger diameter. A hardening time of at least 30 minutes at temperature is recommended.
Source: IS 11169 (Part 1):2022, Table C.12, clauses 8.2.4 and 8.2.6
Active IS 11169 (Part 1):2022 31Cr2Mo1BT Listings on M-EX (For Sale)