300M steel is a basic structural material used in Air Force and commercial systems. Exhibiting deep hardenability, this alloy is typically used in aircraft landing gear assemblies as well as crankshafts, connecting rods and gearboxes for automotive, industrial and agricultural applications. Improved wear resistance and overall durability of components produced from 300M steel can be realized when surface hardening is achieved while maintaining high ductility throughout the bulk of the material. This paper describes the processing method developed to use laser energy to increase the surface hardness of 300M steel. A study was conducted by the Laser Hardening Materials Evaluation Laboratory (LHMEL) located at Wright Patterson Air Force Base, Ohio, to produce an understanding ofthe interaction of CO2 laser energy with 300M steel. Optical energy coupling efficiency data was matched with the thermal conductance properties of 300M steel to develop a processing method resulting in surface hardening. Surface hardness measurements of 60 Rc are reported with processed region thickness extending to a depth of 1mm. The yield strength, ultimate tensile strength and elongation of the laser hardened test bars were measured and compared to untreated and traditionally hardened specimens. The laser hardening process is described and comparisons made between standard surface treatment methods.

1.
Thornton
,
P. A.
 and
V. J.
Collomselo
 (
1985
).
Fundamentals of Engineering Materials
,
Prentice Hall
,
New Jersey
.
126
–
128
.
Google Scholar
 
2.
Landgraf
,
R. W.
 and
R. H.
Richman
 (
1973
).
Fatigue Behavior of Carburized Steels
.
ASTM Special Technique Publication
569
.
130
–
142
.
Google Scholar
 
3.
Vukovich
,
D.
 and
R.
Pierman
 (
Feb
. 28 -- Mar 4,
1977
).
Laboratory Evaluation of New Alloy Gear Steels
.
SAE Paper 770416
.
Google Scholar
 
4.
D. E.
Diesburg
 (
1971
).
Residual Stress Measurement by X-Ray Diffraction
.
SAE Paper 7849
.
Google Scholar
 
5.
Parrish
,
G.
 (
1976
).
Heat Treatment of Metals
, Vol.
3
.
ASM International, Cleveland, Ohio
. p
73
-
79
.
Google Scholar
 
6.
Sanders
,
O. A.
 (
1992
).
ASM Metals Handbook
, Vol.
4
.
ASM International, Cleveland Ohio
.
286
–
292
.
Google Scholar
 
7.
Mazumdar
,
J.
(
May
,
1983
). Laser Heat Treatment: The State of the Art.
Journal of Metals
.
18
–
26
.
Google Scholar
 
8.
Grotke
,
G. E.
,
G. J.
Bruck
,
J.E.
Smith
 and
J. I.
Nurminen
 (
1984
). A Parametric Study of Surface Transformation Hardening with High-Powered Lasers.
Research and Development Report (AD# A140160)
,
Westinghouse Research and Development Center
.
Google Scholar
 
9.
Saunders
,
R. J.
 (
July
,
1984
).
Laser Metal Working
.
Metallurgical Progress
.
45
–
51
.
Google Scholar
 
10.
Fukuda
,
T.
,
M.
Kikuchi
,
A.
Yamanishi
 and
S.
Kiguchi
 (
March
,
1985
).
Laser Hardening of Spheroidal Graphite Cast Iron Minimizes Distortion While Increasing Wear Resistance
.
Industrial Heating
.
41
–
44
.
Google Scholar
 
11.
Philip
,
T. V.
 and
T. J.
McCaffery
 (
1985
).
ASM Metals Handbook
, Vol.
1
, 10th Edition.
ASM International
, Cleveland Ohio.
430
–
437
.
Google Scholar
 
12.
(
1993
).
Annual Book of ASTM Standards
, Vol.
0301
.
ASTM, Philadelphia PA
.
432
–
455
.
13.
Powell
,
J.
,
H.
Engstrom
 and
C.
Manusson
 (
May
,
1994
).
Laser Surface Treatment, Mechanisms and Techniques -- Part I
.
The Fabricator
.
80
Google Scholar
 
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