Hardness HRC at a distance from quenched end of test piece(in mm) of
1,5
3
5
7
9
11
13
15
20
25
30
35
40
45
50
25CrMo4 25CrMoS4
+HH
850
max.
52
52
51
50
48
46
43
41
37
35
33
32
31
31
31
min.
47
46
44
41
39
37
34
32
28
26
24
23
22
22
22
+HL
max.
49
49
47
46
43
41
38
36
32
30
29
28
27
27
27
min.
44
43
40
37
34
32
29
27
23
21
20
—
—
min.
53
53
53
53
52
51
51
51
51
50
50
50
50
49
48
min
50
50
50
50
49
48
48
48
48
47
47
47
46
45
44
This table is not applicable to steels ordered with a restricted range of carbon content,see footnote c)in Table C.2.
表C.10-芯部硬度试验中至少应获得90% 马氏体的最大直径 (+ CH等级)
Steel name
Symbol
Austenitizing temperature in the core hardening testa C±5℃
Min.core hardness ( 90 %martensite structure) HRC
Maximum diameter to ensure 90 %of martensite in the coreb mm
25CrMo4
+CH
850
41
13
a As a guideline,a hardening time at temperature of at least 30 min is recommended. The maximum diameters stated are those attainable with the lowest hardenability within each steel grade.Using +HH grades the maximum diameter can be increased.
