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
P
Cr
Mo
Al (metallic)
0.10-0.18
0.10-0.35
0.40-0.70
<=0.040
0.70-1.10
0.45-0.65
<=0.02
Mechanical Properties
Tensile Strength
440-590 MPa
Yield Strength
>=275 MPa (0.2 % proof stress)
Elongation
>=22%
Condition
Pipes, N+T, thickness - (first row of Table 3)
More data from IS 1570 (Part 7):1992
From the standard
Mechanical properties at room temperature7 rows
Product
Heat treatment
Thickness (mm)
Hardness (RB)
Rp0.2 min (MPa)
Rm min (MPa)
Rm max (MPa)
Elongation min (%)
KV (J)
Bend test D max
Pipes
N+T
-
-
275
440
590
22
-
-
Plates
N+T
over 3 to 16
-
305
470
620
20
-
3a
Plates
N+T
over 16 to 40
-
305
470
620
20
-
3a
Plates
N+T
over 40 to 63
-
305
470
620
19
-
3a
Plates
N+T
over 63 to 100
-
Note 8
470
620
18
-
3a
Bars, forgings
N+T
-
255
410
560
-
18
-
-
Bars, forgings
Q+T
-
-
375
540
690
15
-
-
Rm and elongation printed once for a group of thickness rows are repeated on each row; Rp0.2 'Note 8' is printed as in the standard; in case of dispute the tensile strength value is deciding.
Source: IS 1570 (Part 7):1992, Table 3
0.2 % proof stress at elevated temperature (guidance only)Rp0.2 min in MPa
Product, heat treatment, thickness
100 deg C
150 deg C
200 deg C
250 deg C
300 deg C
350 deg C
400 deg C
450 deg C
500 deg C
550 deg C
600 deg C
Pipes, N+T, up to 40 mm
240
230
220
210
183
169
164
161
156
151
146
Plates, N+T, up to 60 mm
270
259
248
237
-
203
199
194
188
181
174
Bars, forgings, N+T, Q+T
210
200
192
180
150
135
130
127
124
120
117
For guidance only.
Source: IS 1570 (Part 7):1992, Table 4
Heat treatment9 entries
Normalising temperature (N+T)
900 to 960 deg C
Normalising time
1 to 2 min per 1 mm thickness of forging or pipe wall but not less than 20 min
Normalising cooling
in quiet air
Tempering temperature
640 to 720 deg C
Tempering time
1 to 3 min per 1 mm thickness but not less than 15 min
Stress relief or tempering after bending or welding
660 to 710 deg C, 2 min per 1 mm thickness but not less than 15 min
Quenching temperature
900 to 930 deg C
Quenching medium
oil or water
Tempering temperature after quenching
620 to 720 deg C
Indications are for guidance only except where test samples are reference heat treated; stress relief temperature should be at least 30 deg C below the tempering temperature.
Source: IS 1570 (Part 7):1992, Table 5
Active IS 1570 (Part 7):1992 12Cr4Mo5H Listings on M-EX (For Sale)