A prehardened mold steel (311-345 HB / 33-37 HRC) with improved machinability
41X40 is a chromium-manganese-molybdenum grade designed for plastic mold industry. This grade is normally delivered in a prehardened condition at a hardness level of 33/37HRC. The grade has a fully homogeneous martensite-bainite microstructure. 41X40 grade has specific sulfur addition (0.060% typical) in order to increase strongly its machinability. Compared to AISI P20 grade, 30% increase in milling speed and 300% increase in drilling speed can be expected. At constant cutting speed, tool life is multiplied a least by 5 when replacing P20 by 41X40 grade.
41X40 is not suitable for polishing requirements.
This grade is typically used for:
1.Plastic injection molds for thermoplastics
2.Extrusion dies for thermoplastics
3.Compression molds
Chemical Analysis
Typical values (weight%)
C
|
S
|
P max
|
Si
|
Mn
|
Cr
|
Mo
|
0.4
|
0.060
|
0.012
|
0.3
|
1.5
|
1.9
|
0.2
|
Mechanical Properties
Typical values for plates air quenched and tempered (thickness 45 mm – 1.8”).
|
Hardness
|
YS 0.2
|
UTS
|
Elongation
|
Reduction
of area
|
Elastic modulus
|
|
HB
|
MPa
|
ksi
|
MPa
|
ksi
|
%
|
Z%
|
GPa
|
ksi
|
Longitudinal
direction
|
320
|
920
|
133
|
1075
|
156
|
9
|
40
|
205
|
29745
|
Longitudinal
direction
|
320
|
900
|
131
|
1060
|
154
|
8
|
35
|
205
|
29745
|
Delivery Conditions
Typical delivery sizes
Thickness
|
Width
|
20 – 120 mm
(.79″ – 4.7″)
|
1500 – 2500 mm
(59 – 98.4″)
|
120 – 600 mm
(4.7″ – 23.6″)
|
1500 – 2100 mm
(49″ – 82.7″)
|