This study illustrates the influence of different material surface conditions on the absorption characteristics of the laser beam. Flat rolled 5 mm thick locally manufactured Iscor Bennox® wear plate with a similar chemical composition to AISI 1055 was used as base material. This material is within the medium carbon range, which is suitable for transformation hardening. Eight samples were prepared with different surface conditions. Each sample was treated with the same CW CO2 laser using output power settings between 1 and 5 kW. The specimens were sectioned and prepared according to standard metallographic techniques to a surface finish of 1 µm before etching. The size and penetration depth of the heat-affected zone was used as a measure to determine the influence of surface condition on the absorption characteristics of the laser beam. Vickers micro-hardness tests were conducted to confirm that transformation hardening occurred during the laser treatment.

1.
Reed-Hill
,
R.E.
:
Physical metallurgy principles.
Second edition (
1973
),
701
746
2.
Chandler
,
H.
:
Heat treater’s guide
.
Practices and procedures for irons and steels.
Second edition (
2000
),
36-76
,
196
197
3.
Steen
,
W. M.
:
Laser material processing.
Second Edition (
1998
),
222
231
4.
Ready
,
J.F.
:
Absorption of laser Irradiation LIA Handbook of laser materials processing
, (
2001
),
183
184
5.
De Pascale
,
O.
;
Esposito
,
C.
;
Lepore
,
M.
;
Boffi
,
P.
:
Coating Characterization in controlled Surface Temperature Laser Heat Treating
.
Optics and Lasers in Engineering
, (
1988
),
97
108
6.
Ashby
,
M. F.
;
Easterling
,
K. E.
:
The transformation hardening of steel surfaces by laser beams
.
I. Hypo-eutectoid steels; Acta metal.
Vol
32
, No
11
, (
1984
)
1935
1948
7.
Mazumder
,
J.
:
Laser heat treatment: The state of the art
.
Journal of metals
(May
1983
),
18
26
8.
Müller
,
K.
;
Bergmann
,
H.W.
:
Surface treatment: Heat treating
. In:
Ready
,
J.F.
;
Farson
,
D.F
. (Edtrs.):
LIA Handbook of laser materials processing
, (
2001
),
245
246
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