Steels_ Metallurgy and Applications, Third Edition

Engineering steels 227

+0.4

E

E +0.3

~+0.2

C 0

C

.~_ +0.1

c-

O

-0.1

-0.2

(a)

,,=.

o CM80

& CM60

._ o637H17 (En352)

9 835H15 (En39B)

9 822H17 (En355)

.,.=,,

-- 13

ted Water

t ~01 t quench t quenching oll t quench

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

(b)

,,,,,

Water

cool ~ quench t quenching 011 t quench

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

H value for quench

C

e,,. tJ

.o 09

r |

.E_

"o p. -0.1

=[

0.2[- (c)

0.1~ ,,/~

-0.2

~b

Air Slow oll Accelerated Water

t cool ~quench tqu enching ~ lit quench I ,

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

H value for quench

Figure 3.22 Effect of quenching rate on mean dimensional change in (a) outer diameter,
(b) bore diameter and (c) middle thickness (After Llewellyn and Cook 15)

Standard specifications

The major UK standard for engineering steels is BS 970: Part 1' 1996 Wrought
steels for mechanical and allied engineering purposes. It deals with steels of the
following type in the form of blooms, billets, slabs, bars, rods and forgings"