|
18CrMo4
EN 10084-1998, Number: 1.7243
|
|
Comparison of steel grades
|
|
JUS
|
-
|
|
DIN
|
-
|
|
BS 970
|
708M20
|
|
GOST
|
-
|
|
AISI
|
-
|
|
UNI 7846
|
18CrMo4
|
|
NF A35-551-86
|
18CD4
|
Chemical composition (cast analysis)
|
Chemical elements
|
C
|
Si
max
|
Mn
|
P
max.
|
S
|
Cr
|
Mo
|
-
|
|
%, by mass
|
0,15-0,21
|
0,40
|
0,60-0,90
|
0,035
|
≤ 0,035
|
0,90-1,20
|
0,15-0,25
|
|
|
Permissible deviation
|
± 0,02
|
+ 0,03
|
± 0,04
|
+ 0,005
|
+ 0,005
|
± 0,05
|
± 0,03
|
-
|
Hardness limits for
steel
|
Hardness HRC at a distance from
quenched end of test piece (in milimetres) of
|
|
mm
|
1,5
|
3
|
5
|
7
|
9
|
11
|
13
|
15
|
20
|
25
|
30
|
35
|
40
|
45
|
50
|
|
+H
|
max.
|
47
|
46
|
45
|
42
|
39
|
37
|
35
|
34
|
31
|
29
|
28
|
27
|
26
|
-
|
-
|
|
min.
|
39
|
37
|
34
|
30
|
27
|
24
|
22
|
21
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
+HH
|
max.
|
47
|
46
|
45
|
42
|
39
|
37
|
35
|
34
|
31
|
29
|
28
|
27
|
26
|
-
|
-
|
|
min.
|
42
|
40
|
38
|
34
|
31
|
28
|
26
|
25
|
22
|
20
|
-
|
-
|
-
|
-
|
-
|
|
+HL
|
max.
|
44
|
43
|
41
|
38
|
35
|
33
|
31
|
30
|
27
|
25
|
24
|
23
|
22
|
-
|
-
|
|
min.
|
39
|
37
|
34
|
30
|
27
|
24
|
22
|
21
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
Hardness requirements for products
delivered in the conditions ’’treated to improve shearabilita’’ (+S), ’’anneled
to maximum hardness requirements’’ (+A), ’’treated to hardness range’’ (+TH) or
’’treated to ferrite-pearlite structure and hardness range’’ (+FP)
|
Brinell hardness in the condition
|
|
+S max.
|
+A max.
|
+TH
|
+FP
|
|
min.
|
max.
|
min.
|
max.
|
|
*
|
207
|
156
|
207
|
140
|
187
|
Non-metallic
inclusions
Requirements for microscopic degree of purity when
tested in accordance with
DIN 50 602 (method K) (valid for oxidic non-metallic
inclusions)
|
D (mm)
Bars Diameter d (mm)
|
K
Total characteristic value K
(oxides) for the individual cast
|
|
140 < d 200
|
K 4 ≤ 50
|
|
100 < d ≤ 140
|
K 4 ≤ 45
|
|
70 < d ≤ 100
|
K 4 ≤ 40
|
|
35 < d ≤ 70
|
K 4 ≤ 35
|
|
17 < d ≤ 35
|
K 3 ≤ 40
|
|
8 < d ≤ 17
|
K 3 ≤ 30
|
|
d ≤ 8
|
K 2≤ 35
|
Conditions for heat treating test
bars and treatment of the steels
|
End quenchh test
Quenching, 0C
|
Carbunnzing temperature,
0C
|
Core-hardening
temperature, 0C
|
Case-hardening
temperature, 0C
|
Tempering, 0C
|
|
880
|
880 to 980
|
860 to 900
|
780 to 820
|
150 to 200
|
|
18CrMo4
EN 10250-3:1999, Number: 1.7243
|
|
Comparison of steel grades
|
|
JUS
|
-
|
|
DIN
|
-
|
|
BS 970
|
708M20
|
|
GOST
|
-
|
|
AISI
|
-
|
|
UNI
|
-
|
|
NFA35/551/86
|
18CD4
|
Chemical analysis -% by mass*
|
Chemical elements
|
C
|
Si
|
Mn
|
P
max.
|
S
max.
|
Cr
|
Mo
|
-
|
-
|
|
% , by mass
|
0,15- 0,21
|
£ 0,40
|
0,60-0,90
|
0.035
|
0.035
|
0,90-1,20
|
0,15-0,25
|
-
|
-
|
|
Permissible deviation
|
± 0,02
|
+ 0,03
|
± 0,04
|
+ 0,005
|
+ 0,005
|
± 0,05
|
± 0,03
|
-
|
-
|
* At
the option the manufacturer the elements aluminium, titanium, vanadium and
niobium may be added singly or in combination for grain control
purposes. Elements not quoted in tables shall not be added intentionally to
the steel without the agreement of the purchaser, except for the purpose
of finishing the heat.
Mechanical properties in the
quenched and tempered condition
|
Thickness of ruling
section tR
|
|
Diameter in mm
|
tR ≤ 160mm
|
|
160< tR
≤330mm
|
330<tR≤660mm
|
|
Re min (N/mm2)
|
275 (Rp 0.2)
|
|
-
|
-
|
|
Rm (N/mm2)
|
485-660
|
|
-
|
-
|
|
A % min.
|
l-longitudinal
|
20
|
|
-
|
-
|
|
tr - transverse
|
20
|
|
-
|
-
|
|
KV min (J)
|
l-longitudinal
|
50
|
|
-
|
-
|
|
tr - transverse
|
50
|
|
-
|
-
|
1N/mm2=1MPa
Heat treatment conditions ****
|
Quenching temperature,
0C
|
Tempering temperature, 0C
|
|
850 to 880
|
595 to 700
|
****
Quenching
from hardening may be carried out in oil, water, or water based solutions. Caution
should be observed in the use of water as a
quenching medium to avoid the risk of cracking the forgings |
 |
|
|
Zeljezara Niksic - Niksic, Montenegro
Phone: (+382) 20 234-616, (+382) 40 202 900 | Fax: (+382) 40 202-023
 | Website: www.znksteel.com
|
|
