Steels_ Metallurgy and Applications, Third Edition

Engineering steels 283

Table 3.27
, ,,
Country Grade

Tensile properties and hardness of micro-alloy forging steels

Germany 49MnVS3
Gr. Britain BS970-280M01
Gr. Britain (LIES) VANARD 850
Gr. Britain COES) VANARD 1000
Gr. Britain CMV 925
(Austin-Rover)
Finland (OVAKO) IVA 1000
Sweden
(Volvo)
Germany
Germany
Germany
Japan
(Mitsubishi-NKK)

After Korchynsky and Paules. 49

UTS YS

(MPa) (MPa)

750-900 450 min.

780-1080 540-650

770-930 540 min.

930-1080 650 min.

850-1000 560

El (% RA (% BHN

min.) min.)

8 20

18/8 20

18 20 237-277

12 15 269-331

12 15 248-302

1025 750 10 20

V-2906:<90 mm 750-900 500 min. 12

<50 mm 800-950 520 min. 15

44MnSiVS6 950-1100 600 min. 10 20

38MnSiVS6 820-1000 550 rain. 12 25

27MnSiVS6 800-950 500 min. 14 30

720-800 470-550

290

230-275

245-290

Table 3.28

Grade

VANARD 850

VANARD 925

VANARD 1000

VANARD 1100

Steel replaced

0.35% C, 1.5% Mn (216M36)

0.35% C, 1.5% Mn, 0.25% Mo (605M36)

0.4% C, 0.8% Mn, 1% Cr (530M40)

0.35% C, 1.5% Mn, 0.25% Mo (605M36)

0.4% C, 0.8% Mn, 1% Cr, 0.3% Mo (709M40)

0.4% C, 0.8% Mn, 1% Cr, 0.3% Mo (709M40)

grade V2906, 49 MnVS3 has a relatively low manganese content which restricts
the amount of pearlite in the microstructure, and the tensile strengths of these
grades are towards the bottom of the range. In the UK, substantial effort has been
devoted to the development and commercial evaluation of the VANARD range
which is based on the following composition range:

0.3-0.5% C, 0.15-0.35% Si, 1-1.5% Mn, 0.05-0.2% V

Within this composition range, increasing levels of carbon, manganese and vana-
dium are used to provide tensile strengths in the range 850-1100 N/mm 2.
Some of the quenched and tempered, alloy steels that can be replaced by the
VANARD grades are shown in Table 3.28.
Whereas the standard VANARD grades are generally made to a sulphur
specification of 0.05% max., variants are produced with sulphur contents of the
order of 0.08% for improved machinability. Other steels listed in Table 3.26 also
specify enhanced sulphur levels. However, irrespective of the sulphur content, it
is generally claimed that micro-alloy forging steels offer better machinability than