EN 10083-1:1991 25CrMoS4 Steel: Specifications & Listings
EN 10083-1:1991 25CrMoS4: A chromium molybdenum alloy steel for quenching and tempering to EN 10083-1:1991 (printed 25 CrMoS 4), with controlled sulphur of 0.020 to 0.040% for better machinability. Supplied as semi-finished products, bars, rod, wide flats, hot rolled strip, sheet and plate, and forgings. Quenched and tempered tensile strength 900 to 1100 MPa for ruling sections up to 16 mm.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Cr
Mn
Mo
P
S
Si
0.22-0.29
0.90-1.20
0.60-0.90
0.15-0.30
<=0.035
0.020-0.040
<=0.40
Mechanical Properties
Condition
Quenched and tempered, ruling section d <= 16 mm
Elongation
12% min
Hardness
Soft annealed: 212 HB max
Tensile Strength
900 to 1100 MPa
Yield Strength
700 MPa min
More data from EN 10083-1:1991
From the standard
Other composition limitsTable III and its notes
Designation as printed
25 CrMoS 4
Pair grade
25CrMo4 has the same limits except sulphur, max. 0.035
Improved machinability
Steels with lead or higher sulphur, up to about 0.100% S, may be supplied on request (Table III, note 3)
Elements not quoted in Table III are not intentionally added without the purchaser's agreement, other than for finishing the heat. With hardenability requirements, slight deviations within Table IV are permitted except for carbon, phosphorus and sulphur.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table III and its notes
Mechanical properties, quenched and tempered4 sections
Ruling section
Yield strength Re, min (MPa)
Tensile strength Rm (MPa)
Elongation A, min (%)
Reduction of area Z, min (%)
Impact KV, min (J)
d <= 16 mm, t <= 8 mm
700
900 to 1100
12
50
45
16 mm < d <= 40 mm, 8 mm < t <= 20 mm
600
800 to 950
14
55
50
40 mm < d <= 100 mm, 20 mm < t <= 60 mm
450
700 to 850
15
60
50
100 mm < d <= 160 mm, 60 mm < t <= 100 mm
400
650 to 800
16
60
45
Re is the upper yield strength or, if no yield phenomenon occurs, the 0.2% proof strength; A on gauge length 5.65 times the root of the original cross section; KV on longitudinal ISO V-notch test pieces, average of 3 values, no single value below 70% of the minimum. Ruling sections as in Appendix B. Sizes not listed are not covered by the standard.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table IX
Maximum hardness by delivery conditionTable VIII
Treated to improve shearability (TS), max
255 HB
Soft annealed (TA), max
212 HB
Values also apply to the grades with hardenability requirements (H, HH, HL); not applicable to continuously cast slabs not further deformed.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table VIII
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
52
52
51
50
48
46
43
41
37
35
33
32
31
31
31
Minimum, HRC
44
43
40
37
34
32
29
27
23
21
20
Applies when ordered with the letter H. End quench test at 850 ± 5 deg C (Table XIII).
Source: EN 10083-1:1991 (UNI EN 10083-1), Table V
Restricted hardenability (HH, HL), HRCTable VII
Limit
1.5 mm
3 mm
5 mm
7 mm
9 mm
11 mm
13 mm
15 mm
20 mm
25 mm
30 mm
35 mm
40 mm
45 mm
50 mm
HH max.
52
52
51
50
48
46
43
41
37
35
33
32
31
31
31
HH min.
47
46
44
41
39
37
34
32
28
26
24
23
22
22
22
HL max.
49
49
47
46
43
41
38
36
32
30
29
28
27
27
27
HL min.
44
43
40
37
34
32
29
27
23
21
20
-
-
-
-
Restricted scatter bands by distance from the quenched end.
Source: EN 10083-1:1991 (UNI EN 10083-1), Table VII
Heat treatmentTable XIII
Quenching
840 to 880 deg C
Quenching agent
Water or oil
Tempering
540 to 680 deg C
End quench test
850 ± 5 deg C
Guidance values except the end quench test temperature, which is binding. Lower quenching temperatures generally for water, upper for oil; austenitizing at least 30 min, tempering at least 60 min (guide values).
Source: EN 10083-1:1991 (UNI EN 10083-1), Table XIII
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