Steels_ Metallurgy and Applications, Third Edition

Engineering steels 225

0.04

0.02

0

~ , -0.02 -0.04

c3 -0.06

O -O.08

-0.10

-0.12

-0.14

o Centre

o Edge

z Bore

..,

-0.02 -

A -0.04 -

E -0.06 -

c~ -0.08 -

m <3 -0.10 -

-0.12 -

-0.14 -

-0.16

0.12

0.10

E 0.08

o.oe

0.04

0.02

0

0 1.0 2.0 3.0

% Cr

0.01 K-'"r-"- -0.0053 , ,

o.o243 t / o.oo51 [ ( :;1

~------- 0.0114 -0.0109

0.0o86 ~!o.0092 ~/~, ..... <b)l

0.o174;i ~___...'_- o.ooo~ i1 -~176

~,,'0.0471"-,~0.0595

0.0359 1 "~,, ~ I .... ......

( o o~ "~=ooeo3

, ,i]

9 S'

9 0.062 (0.0769

-0.04751 ~O.005i/! l!

-0.0699 I z r! o13'1" " I-o t ~.055 (e)

Figure 3.20 Effect of chromium on dimensional change. Left top: outer diameter change.
Left centre: bore diameter change. Left bottom: thickness change. Right: (a) 1.03% Cr;
(b) 1.5% Cr; (c) 2.05% Cr; (d) 2.55% Cr; (e) 3.03% Cr (After Llewellyn and Cook tS)

Llewellyn and Cook showed that carburizing reduces the amount of movement
that occurs in low-alloy/low-hardenability steels and related the effect to the
depression of the Ms-Mf transformation range in the case-carburized region of a
component. It was observed that carburizing had a smaller effect on dimensional
change in highly alloyed steels and this may be related to the fact that these
steels have low transformation ranges.
Cooling rate from the austenitic range was shown to have a dramatic effect
on dimensional movement and water quenching can virtually eliminate the

'l'hble 3.3

Grade

Steels used to investigate the effect of quenching rate on distortion

C Si Mn P S Cr Mo Ni Al B Ti

637H17 (En 352) 0.18 0.28 0.81 0.011 0.037 0.92 0.1 1.1 - - -
822H17 (En 355) 0.18 0.34 0.6 0.025 0.016 1.4,7 0.2 2 0.056 - -
835H15 (En 39B) 0.14, 0.35 0.42 0.012 0.018 1.13 0.21 3.9 0.03 - -
CM60 0.14 0.26 0.98 0.008 0.049 0.31 0.12 0.15 0.014 0.003 ND ~
CM80 0.19 0.35 1.37 0.009 0.045 0.28 0.12 0.17 0.056 0.003 0.051

aND = not determined.