18CrNiMo7-6
| 18CrNiMo7-6 EN 10084-1998, Number: 1.6587 |
Comparison of steel grades |
| JUS |
Ć.4520 |
| DIN |
17CrNiMo6 |
| BS |
- |
| GOST |
- |
| AISI |
4820 |
| UNI |
- |
| NF |
18NCD6 |
Chemical composition (cast analysis)
| Chemical elements |
C |
Si max |
Mn |
P max. |
S |
Cr |
Mo |
Ni |
| %, by mass |
0,15-0,21 |
0,40 |
0,50-0,90 |
0,035 |
≤ 0,035 |
1,50-1,80 |
0,25-0,35 |
1,40-1,70 |
| Permissible deviation |
± 0,02 |
+ 0,03 |
± 0,04 |
+ 0,005 |
+ 0,005 |
± 0,05 |
± 0,02 |
± 0,02 |
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. |
48 |
48 |
48 |
48 |
47 |
47 |
46 |
46 |
44 |
43 |
42 |
41 |
41 |
- |
- |
| min. |
40 |
40 |
39 |
38 |
37 |
36 |
35 |
34 |
32 |
31 |
30 |
29 |
29 |
- |
- |
| +HH |
max. |
48 |
48 |
48 |
48 |
47 |
47 |
46 |
46 |
44 |
43 |
42 |
41 |
41 |
- |
- |
| min. |
43 |
43 |
42 |
41 |
40 |
40 |
39 |
38 |
36 |
35 |
34 |
33 |
33 |
- |
- |
| +HL |
max. |
45 |
45 |
45 |
45 |
44 |
43 |
42 |
42 |
40 |
39 |
38 |
37 |
37 |
- |
- |
| min. |
40 |
40 |
39 |
38 |
37 |
36 |
35 |
34 |
32 |
31 |
30 |
29 |
29 |
- |
- |
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. |
| 255 |
229 |
179 |
229 |
159 |
207 |
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 |
| 860 |
880 to 980 |
830 to 870 |
780 to 820 |
150 to 200 |
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