Applicable requirements in cases where the steel concerned has been ordered with reference to the steel names indicated in
Wire rod
Bar
Wire
T a b les B. 2,B.3,B.4 or B.5
Ta bles B. 2,B.3,B.4,B.5,B.6 or B,7
Optional
As hot-rolled or peeled
+AR or +PE
X
X
X
Chemical composition as specified in Table B.2
Mechanical properties as specified in Ta b le s B.3 ,B.4 and B.5
Chemical compositior as specified in Table B.2
Mechanical properties as specified in Tables B,3, B.4 and B.5
Values for hardenability according to Ta ble s B.6 and B.7
Supplementa- ry or special requirements as specified in Annex Eh
Cold drawn
+AR+C
-
X
X
Cold drawn + spheroidized
+AR+C+AC
-
X
X
Cold drawn + spheroidized+skin passed
+AR+C+AC +LC
-
X
X
Spheroidized or spheroidized+peeled
+AC or +AC +PE
X
X
X
Spheroidized+cold drawn
+AC+C
X
X
Treated to ferrite- pearlite structure and hardness range
+FP
-
X
-
Others
Other delivery conditions may be agreed at the time of ordering
a X=applicable,-=not applicable. b If agreed at the time of the enquiry and order.
2.化学组成
表B.2-表面硬化用钢的化学成分 (适用于铸造分析)
表B.2-表面硬化用钢的化学成分 (适用于铸造分析)
Steel name b
% mass fraction a
C
Si c
Mn
P
S
Cr
Ni
Mo
B
Cu
20NiCrMo7
0,17 to 0,23
0,30
0,40 to 0,70
0,025
0,025
0,35 to 0,65
1,60 to 2,00
0,20 to 0,30
0,25
Elements not quoted in this table should not be intentionally added to the steel without the agreement of the purchaser,except those intended for finishing the heat.All reasonable precautions shall be taken in order to prevent the addition of such elements from scrap or other materials used in the production process,which can affect the hardenability, mechanical properties and applicability To improve the performance of cold heading,it is possible to add Al:0,020 %to 0,050 % a Maximum values unless otherwise indicated. b In the case of steels with hardenability requirements (see Ta bles B. 6 and B.7),minor deviations from the specified limits are permitted (with the exception of sulfur and phosphorus),provided that they do not exceed 0,01 %for carbon and the values indicated in Table 2 for the other elements. c A lower silicon content or a specific silicon range may be agreed at the time of ordering.
3.力学性能
表B.5-合金钢牌号的力学性能
表B.5-合金钢牌号的力学性能 (续)
Steel name
Diameter
Delivery condition
+AC
+FP
+AR+C+AC
+AR+C+AC+LC
+AC+C
above mm
up to mm
Rm max. MPa
Z min %
HB Min.max.
Rm max. MPa
Z min %
Rm max. MPa
Z min. %
Rm max. MPa
Z min. %
20NiCrMo7
2
5
—
—
—
—
5
10
—
680
60
700
55
10
25
—
—
—
—
680
60
—
—
700
55
4.淬透性要求
表B.6-标准淬透性钢种的硬度限值 (H级)
表B.6-标准淬透性钢种 (H级) 的硬度限值 (续)
Steel name
Symbol
Austenitizing temperature °℃±5℃
Limits of range
Hardness HRC at a distance from quenched end of test piece(in mm)of
