TITLE:
Effects of Laser Hardening Process Parameters on Case Depth of 4340 Steel Cylindrical Specimen—A Statistical Analysis
AUTHORS:
Noureddine Barka, Abderrazak El Ouafi
KEYWORDS:
Laser Heat Treatment, Cylindrical Specimen, Hardness Profile, Case Depth
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.5 No.3,
June
10,
2015
ABSTRACT: Laser heat treatment is considered to be one of best-performing manufacturing processes used
currently due to its flexibility and its ability to develop parts with complex geometries. In fact, this
process is able to produce reliable parts with hard, thin martensite and compressive residual
stresses. This paper explores the heat treatment applied to 4340 cylindrical parts heated using a
Nd: Yag 3 kW laser source. In this case, the hardness profile is correlated to process parameters
such as the laser source power, the beam scanning speed and the revolution speed of the part
during heating. Based on preliminary tests stipulating that each parameter is varied alone within
a specific range, a systematic design of final tests is performed using Taguchi matrix. The obtained
results are analyzed using ANOVA method to extract the effects, the contributions and the interaction
between the factors. The results are then exploited to study the sensitivity of the case depth
according the variation of the process parameters. The developed model exhibits good potential
for converging towards a robust model able to predict the hardness curve and to generalize it for
other dimensions of cylindrical parts.