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20NiCrMo2-2
EN 10084-1998, Number: 1.6523
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Comparison of steel grades
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JUS
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Č.7422, Č.75201
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DIN
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21NiCrMo2
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BS
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805M20
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GOST
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-
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AISI
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A322; 8720
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UNI
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20NiCrMo2
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NF
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20NCD2
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Chemical composition (cast analysis)
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Chemical elements
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C
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Si
max
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Mn
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P
max.
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S
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Cr
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Mo
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Ni
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%, by mass
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0,17-0,23
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0,40
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0,65-0,95
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0,035
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≤ 0,035
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0,35-0,70
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0,15-0,25
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0,40-0,70
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Permissible deviation
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± 0,02
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+ 0,03
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± 0,04
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+ 0,005
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+ 0,005
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± 0,05
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± 0,02
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± 0,02
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Hardness limits for
steel
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Hardness HRC at a distance from
quenched end of test piece (in milimetres) of
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mm
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1,5
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3
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5
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7
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9
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11
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13
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15
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20
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25
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30
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35
|
40
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45
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50
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+H
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max.
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49
|
48
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45
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42
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36
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33
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31
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30
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27
|
25
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24
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24
|
23
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-
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-
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min.
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41
|
37
|
31
|
25
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22
|
20
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-
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-
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-
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-
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-
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-
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-
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-
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-
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+HH
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max.
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49
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48
|
45
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42
|
36
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33
|
31
|
30
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27
|
25
|
24
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24
|
23
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-
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-
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min.
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44
|
41
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36
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31
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27
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24
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22
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21
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-
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-
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-
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-
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-
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-
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-
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+HL
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max.
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46
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44
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40
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36
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31
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29
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27
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26
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23
|
21
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20
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20
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-
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-
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-
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min.
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41
|
37
|
31
|
25
|
22
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20
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-
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-
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-
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-
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-
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-
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-
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-
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-
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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)
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Brinell hardness in the condition
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+S max.
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+A max.
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+TH
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+FP
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min.
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max.
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min.
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max.
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*
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212
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161
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212
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149
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194
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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)
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D (mm)
Bars Diameter d (mm)
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K
Total characteristic value K
(oxides) for the individual cast
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140 < d 200
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K 4 ≤ 50
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100 < d ≤ 140
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K 4 ≤ 45
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70 < d ≤ 100
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K 4 ≤ 40
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35 < d ≤ 70
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K 4 ≤ 35
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17 < d ≤ 35
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K 3 ≤ 40
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8 < d ≤ 17
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K 3 ≤ 30
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d ≤ 8
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K 2≤ 35
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Conditions for heat treating test
bars and treatment of the steels
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End quenchh test
Quenching, 0C
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Carbunnzing temperature,
0C
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Core-hardening
temperature, 0C
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Case-hardening
temperature, 0C
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Tempering, 0C
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920
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880 to 980
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860 to 900
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780 to 820
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150 to 200
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 |
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Zeljezara Niksic - Niksic, Montenegro
Phone: (+382) 20 234-616, (+382) 40 202 900 | Fax: (+382) 40 202-023
 | Website: www.znksteel.com
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