l Buderus Plastic Mould Steel 2738 ISO-BM - Buderus Edelstahl GmbH

l Buderus Plastic Mould Steel 2738 ISO-BM
C Si Mn P S Cr Ni Mo
Typical analysis 0.36 0.30 1.50 0.020 0.003 2.00 1.00 0.20
Chemical composition 0.35– 0.20– 1.30– � � 1.80– 0.90– 0.15–
as per SEL
0.45 0.40 1.60 0.030 0.030 2.10 1.20 0.25
Register of European
Steels (SEL)
40 CrMnNiMo 8-6-4
DIN EN ISO 4957 40 CrMnNiMo 8-6-4
AFNOR 40 CMND 8
AISI ~ P 20 + Ni
BS ~ P 20 + Ni
Characteristics
Mould steel for large dimensions > 400 mm thick. Properties as for grade 2311 ISO-BM,
but with improved through-hardening.
Nitridable, hard chrome plateable, fl ame hardenable, polishable, grain-reliable as delivered.
In an extreme dimensional range, and where there is a requirement for
l Higher hardness and better through-hardenability
l Polishability > 320 grit
l Sensitive etch-graining designs (e.g. HNO3) l Higher thermal conductivity
we recommend grade 2738mod.TS(HH).
Figures in % by mass
Applications
Tools for compression and injection moulds, bumpers, dashboards, chairs, rubbish bins, bottle crates,
television cabinets, etc.
Delivered condition
Quenched and tempered to 280–325 HB (� approx. 950–1100 MPa)*
Annealed on request
Physical properties (reference values)
Thermal expansion
coeffi cient (10 –6 /K)
Thermal conductivity
(W/mK)
Young’s modulus
(GPa)
20–100 °C
11.6
20 °C
34.0
20 °C
212
20–250 °C
12.8
250 °C
33.5
250 °C
197
* Surface hardness in Brinell, converted to DIN EN ISO 18265, Table A.1;
we offer no quality guarantee with higher hardness requirements
20–500 °C
14.3
500 °C
33.0
500 °C
175
Buderus Edelstahl GmbH l Steel Bar Sales l Buderusstraße 25 l D-35576 Wetzlar
Telephone +49 (0) 64 41-374 2468 l Fax +49 (0) 64 41-374 2784 l info@buderus-steel.com l www.buderus-steel.com
Buderus Plastic Mould Steel 2738 ISO-BM

l 2738 ISO-BM
Heat treatment
Stress relieving Temperature: Approx. 600 °C in the annealed state
Approx. 550 °C in the quenched and tempered state
Duration: 1 hour per 50 mm wall thickness
Cooling: Furnace
Soft annealing Temperature: 720 °C
Duration: 1 hour per 25 mm wall thickness
Cooling: Furnace
Hardening Temperature: 880 °C
Duration: 1 minute per mm wall thickness
Quenching hardness Max. 54 HRC in oil, hot bath or vacuum
Tempering Temperature: See tempering curve
Duration: 1 hour per 25 mm wall thickness
Cooling: Air
Working hardness 280–325 HB
Tempering curve
Hardness in HRC
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
0 100 200 300 400 500 600 700 800
Tempering temperature in °C
TTT curve (continuous)
Temperature in °C
1200
1100
1000
900
800
700
600
500
400
300
200
100
M s
M f
Average values on samples dia. 25 x 50 mm long
hardened at 880 °C in oil
HB converted from HRC
707 707 707 705 710 650 657 657 642 642 608 514 420 311
HB
(461)
436
413
392
373
354
337
319
303
286
0 1 10 10 2 10 3 10 4 10 5 10 6
Seconds
Austenitising temperature: 880 °C
Ac 3
Ac 1
1
Minutes
10
Time
100 1000 10 000
F
B
P
Through-hardenability (schematic)
Core hardness in HRC
35
34
33
32
31
30
29
28
27
THRUHARD SUPREME® HighHard
Surface hardness = 35 HRC
THRUHARD SUPREME®
Surface hardness = 31 HRC
2738
Surface hardness = 31 HRC
26
2311
Surface hardness = 31 HRC
25
200 400 600 800 1000 1200 1400
Diameter in mm
Legal notice. Buderus Edelstahl GmbH has taken every possible care in compiling this information; the data is nevertheless subject to intervening changes. Buderus Edelstahl GmbH disclaims all liability and any warranty as regards the accuracy, currency,
correctness and completeness of the information provided. The information provided is merely descriptive and indicative in nature, and binding only when expressly agreed as undertakings in a contract made with Buderus Edelstahl GmbH. Buderus Edelstahl
GmbH moreover reserves the right to make changes at any time without prior notice. Buderus Edelstahl GmbH disclaims all liability for loss or damage of any kind, including consequential loss, arising in connection with use of the information provided.
This publication supersedes all previous ones. © Buderus Edelstahl GmbH, Wetzlar, 07/2010